Omg thing that I found that works is instead of pushing the object into the silicone, lay the object down, then push the silicone onto the object. This gives the final a smooth backing and keeps the thickness very close because it doesn’t “roll” over the back of the object. Plus you can put a little more pressure on the silicone and force more air out resulting in higher detail. Nice job! The owl was my favorite
I was going to say, lay it down too. I've made lots of moulds this way. I redo furniture and lots of the scrolls are either cracked or missing so I use the original to make copies. Waaaaay cheaper than buying ready made 👍
Just a note to clear something up for people. Acetic acid curing silicon (the type of silicon used here) does not get accelerated by dish soap. The soap does nothing other than stop it sticking to your hands. The acetic acid in the silicon reacts with water to cure/set. If you read the tube you will see something along the lines of "cures with moisture from the air". So your dish soap does not matter. What matters is mixing the silicon correctly to get the water into the silicon and trap it. The soap does not help to do this. Problems you may run in to with this method. 1. You bought a silicon that does not have acetic acid in it. It is easy to figure out which ones do. Either it will say so on the tube, will read "cured by moisture..." or you will smell a harsh vinegar smell from it. 2. You did not mix in the water correctly which potentially trapped internal sections without any moisture to cure the silicon for larger chunks. Or you did not mix in enough to allow for fast curing. Personally the better method is the corn starch method. Why? 1. it is more controlled and easier for a novice. 2. the corn starch adds volume to the silicon. If you silicon is far more expensive per gram than your corn starch then it makes sense for doing many molds. 3. it is easier and cleaner to work with since your hands don't get covered in silicon and you don't need gloves at any point. Adding the corn starch makes a more tough mold. You get slightly less spring to it (about 10% less spring). But the strength goes up (by a good 50-100% based on weight squish and pull tests, but varies based on how much corn starch you add). This is good for certain applications where you need a tougher rubber. 4. adding corn starch helps it to release easier from rough surface molds. For example a 3d printed mold can be hard to remove from something with the water only method. The cornstarch method helps with release when set. 5. It is easier to know when a corn starch and silicon mold is ready. It self releases from surfaces and sets uniformly. 6. The corn starch gives you the ability to make 100% opaque moldings. For example, if you had a plastic mold of something and you wanted it made of silicon and be opaque you could do it with corn starch. 7. I find you get greater mold resolution from the corn starch. 8. Corn starch silicon is easier to control the sizing, lip etc. A great example of putting some of these benefits into place would be creating a silicon foot for a subwoofer. They are heavy so you need that extra strength. Otherwise you would end up with a much larger and slightly more ineffective at sound dampening silicon foot. You could also make it opaque to hide it or make it stand out. For example, a solid black or white foot. Both would be hard to do with the water method. Requiring a lot of ink which can be expensive (especially whitening ink). I am sure I am forgetting or don't know some more benefit's. However I am sure that sums it up well.
Ryan Spencer hi. Yes you could do that. How much silicon you would need is very specific to how large the cylindrical toy is however. Just remember a tube of silicon does go a long way. Especially since it increases in volume with the corn starch. Also remember that the more corn starch you add the stiffer and harder to compress the mold will be. Now specifically the biggest decision/issue you are going to have is what type of filling methods you should use. There are quite a few ways. Some more suited to certain things than others. Parts that must be solid with no seam. Not even a slight seam. Then you will want to look up "block molds" on UA-cam. You will find they use liquid silicon. But with a slightly smaller amount of corn flower it will be easy to mash it into whatever container you use. And I do suggest using a container. Something roughly the shape you are going for. Or if you can't do that. Just make sure the walls around what you are making a mold of, are really thick. 2-3cm or about an inch. At the least. You need it thick enough to be able to hold the weight of the filling you are going to put in and also to be able to be demold without breaking. If you do go with the block mold then you need to make sure you add a spout to fill the mold. Otherwise if a seam is not an issue then go with a 2 part mold or a half mold if you part if symmetrical. Look up punished props academy on UA-cam. He does silicon molds very well. There is a Tested video on UA-cam as well with Bill from punished props where they did a lightsaber. They used liquid silicon. But if you kind of use similar methodology by making a block and then squishing your part into it then that will work. Really it depends on your model. Feel free to message me if you need some more help.
Martin B, well done. Thanks to your overly precise, lengthy & acurate comment I am forced to "like" this video. This, will enable me to find your comments & instructions again.
Awesome! I'm a preschool teacher and my students LOVE painting plaster of Paris! I was having such a hard time finding appropriate molds...now I can just make my own! Thank you!
Have kids bring their favorite objects from home (more than one) then give them as a Valentine gift or Christmas ornament. Put a piece of a plastic straw in to keep a hole open for a cord, rope, chain or ribbon.
Excellent video. I've done set design work at a community college for degree credits, and there was nothing like this. It's a great way to borrow items, and create the props with realistic texture for the actors to use. I've known about these techniques, but only helped out with them on jobsites for construction, using the silicon to mold parts for all different kinds of construction or reconstruction. I've even seen it used to restore old detailed work, and been taught how. When you are trying to get detail, the key point you have to remember is "consistent and constant weighted pressure". This is where dowels or something similar would come in handy with your coin or almost any mold. Also, it's best if your molds are "Contained" or bounded by something with firm substance. The widest bottle cap or jar lid you can find would work. The reasoning is that you don't want the mold to get too soft around the object in some places, you want it to be firm and equally so, all over the entire mold surface. That way, when the object you're molding is placed within, the silicone gets compacted instead of spreading away, putting back pressure on the object and filling into the detail rather than spreading flat away from it. When you get a flat plastic piece the same size as the inner container, you can utilize that. By placing a weight on top of the center, you allow it to press the object into the mold when first making it. If you use clamps, it may be necessary to use four in direct cross, two exactly opposite one another, to keep the flat even. Again, this compresses the silicone, and pushes air bubbles around the detail out of the way. When you fill in the resin, you should also put the plastic over and put a small weight on top. This will maintain the firmness of the mold, and the resin will set with greater detail. There are some other tricks that, when used together with the above, allow you to make a two-side recreation, using only a clamp to hold two sides together, allowing for the material to dry as two sided, with only a little excess in a few places. With little work, excess is removed, keeping the details. If you cut a slice into the mold at the outer edge, with a ruler or something similar, and use the same implement on an opposite side, you can align a two sided mold later, making a two sided object with the sides aligned. To do this with many molds, you could use the same ruler or object for making the silicate molds, and the same lids, with a slice taken out. You can use similar lids, slightly cut away, but aligned the same way, for resin setting with single or double-side molds.
I use the GE brand 100% waterproof all purpose clear silicone 1 caulk to make my molds - both soap and cornstarch methods, depending on the application. Recently i mixed in a few drops of glycerine with a little acrylic paint for glow in the dark and blacklight glow molds! I plan to try talcum powder instead of cornstarch - its chemical composition should react with acetic acid with h2o as a biproduct.. might make for an interesting race against the cure clock! Here's some notes I've taken: The retardant is the acetic acid in these 'condensation cure' type silicones - slows the cure, thins the caulk, vinegar smell during cure. The soap is to wash away the retardant and make the silicone pliable, knead in water for quick cure. Cornstarch/Glycerine also speed the cure by distributing moisture, however the smell is much worse if the retardant was not washed out, prior. Glycerine adds elasticity, much faster cure. Cornstarch adds rigidity, next fastest cure. Soap adds pliability, lightens and allows for moisture incorporation. Refrain from casting metal, oops, as the acetic acid will react with it - discoloring the mold, worsening the odor/fumes. Refrain from using latex gloves, enamel paint, anything with sulphur - inhibits cure, stays sticky icky. Now go, and become the mold making guru you were meant to be! 😂
"Refrain from using latex gloves, enamel paint, anything with sulphur - inhibits cure, stays sticky icky." All of the molds i made left the resin pieces very sticky...Mess! what did i do wrong! the pieces i used was metal!
This tutorial is awesome! I do body casting for fun and profit. All my pieces are one of a kind, but making a mold this way is SO much easier than the moldmaking materials that are sold. I've GOT to play with this!
That's useful to know about caulking. I'll give that a whirl. Thanks for sharing. For future reference: in order to get fine details in the centre of the star ornament, it would be best to glue the original (face up of course) to a smooth backboard. Mold the silicone into a ball with a slight peak. Press the peak into the deepest recess in the centre and then press the silicone ball over the whole, flattening it onto your pattern. This ensures that the recess is filled and the air is forced out (it was trapped air that prevented the silicone from making firm contact with the pattern). Peel the mold off when hardened. This will give the mold a clean flat edge, allowing for a neater casting. There. I hope this tip will be as useful to you as your tip is to me. Thanks again.
Instead of pressing the moulding flat, make a dome... So when you press down - Like with the snowflake - the star in the middle hits the mould first and then you press it down to create the mould ;)
That's what I was going to say. The star in the middle of the snowflake clearly got messed up by trapped air. This was also the case for the coin, and the lettering on the Hufflepuff pin.
I'm thinking I can duplicate missing hardware off antique dresser I've had since childhood to help restore it. I'm going to try it. thanks for video. cool!
Yes, this should work! I've done exactly that to repair a broken antique lamp piece, though I used a store-bought silicone putty at the time. You can see those results here on the blog, plus I share some tips on how to attach it to metal and repair the seams, if you have any: www.epbot.com/2017/03/molding-casting-to-repair-worlds.html
I was thinking the same thing. We have a Martha Washington sewing table that is missing a drawer knob. I was going to mix sawdust with glue and put it into a mold.
Cool tutorial, and I like the molds you and your husband painted! Can think of lots of things to make with the recipe, like molds for furniture, charms for journals, pens for gifts. Thanks so much for doing this!
Thanks for demonstrating this! I needed a molding material to recreate a wood detail that is missing from an old piece of furniture. Just what I needed!
Great video. You are really great at giving the viewer good clear instructions. I hope you don't mind me giving you a little advice from my own experiences with molding. I do believe though that with more time and practice, you can get more details from what you are taking molds of. I found that laying flat backed on a smooth surface and then gently pressing the silicone onto the top of the item to be molded helps to get a better-detailed mold and press it down around the edges so you get a nice smooth and flat top to the edges of the item being molded. Then use something flat to press down from the top of the silicone, to form a flat bottom to the mold. It also helps if you can try and make sure that the surface of the silicone that will be making contact with the item is as smooth as possible too so you're not introducing extra textures that shouldn't be there. You could also place the item into something like a cookie cutter and do the same as I mentioned above, inside the cookie cutter to get a more uniformed shape to the edge of the mold. Any, I really hope this is of use for either yourself or any of your viewers. All the best, Diane xx
balacollie ⬅️ I was wondering if anyone was going to address this "reverse" process of pressing the media onto the mold object & using a barrier ring container for compressing & leveling the mold itself for greater detail & uniformity. The next step is making mold-halves for 3-D objects that can be banded together. Thank you for bringing this up! Greatly appreciated! I would really like to know if there is heat generation during curing, as I would like to make 4" x 1-1/2" cylinder candles... Suggestions?
The advantage of working upside down is also the top of the mold is flat. Particularly useful when filling the mold with plaster of paris and striking the filling off to produce flat backed roses for repeat use along a cornice, since they need to all be exactly the same depth.
I use silicone nearly every day. I would never have thought of doing that with it. Try wax polishing the objects before putting them in the silicone mould. The better the polished shine the better the copy is. It's the wax componds in soap that stops it sticking. It releases from the mould easier with out as much damage to the fine detail. Cool video. Thank you.
Hello...thanks so much for making this video. I was always trying to find a way to add 3D "ephemora" to my art projects...and this has solved the issue. I am making an abstract painting for a mechanic friend and was able to mold some bolt heads and create some 3D bolts to add to my project! Thanks again. Ignore the haters. They exist, but can never keep an artist down. We already have beaten so many odds just to make art, and sell art, and be recognized as artists, that no hater can get us get the best of us! Good luck to you and your lovely assistant.
Super informative, great visual tutorial, and I'm really glad you showed what the end results could look like when detailed. A lot of the time that crucial step is left out and leaves the tutorial feeling unfinished. Great Job!
Wow! Thank you!!! On a budget this is awesome for a project I have been pondering and trying to figure out how to do this without spending time looking and finding what I need... perfect!!!! I already have everything I need at home!! No more shopping online for the answer...I found it in this video!! Again, THANK YOU!
Thanks for showing this. I have been trying to figure out a way to do a mold for a replacement part on an old doll. I'm going to give this a shot. Thanks again
I’ve watched a ton of videos trying to decide if I wanted to try the dishwashing detergent with silicone or the cornstarch method. Your tutorial is by FAR the best video of them all.. Definitely the most helpful, and you sold me! I have been sitting here for a week with all the ingredients trying to decide. I wish I had watched your video to begin with. Thank you so much! I am subscribing to your channel now. 😘
Miranda, me too. I've watched videos on both methods and have all of the ingredients trying to decide. I'm going with the cornstarch method because someone stated above that it is a little more rigid than the soap version. I will be making texture plates for polymer clay, so the silicone "mold" will have to be flat and relatively thin. BTW, did you see the video with the cute hunting/para-military dude doing this with silicone and corn starch?
I just wanna say,, great demo,, definitely gonna try this out. I've cast with smooth on before,, mostly two part molds. I wanted to touch on that because the two part mold process can be used on a one surface piece. So,, if you revisit this like the seahorse or hufflepuff pin you could have clay be your base,, mush the back of the pin into the clay and make it flush then place your silicone over it yielding cleaner results.
You did a great job ! I worked making silicon molds omg they take hours to do plus hours to cure. Then the special equipment to do it all. I took a master mold making class just to make them. Your way is fast easy to do I love it !
perfect. thanks. Ive used commercial mold material but since I don't qualify at professional volume for discounts, it becomes very expensive. This is a great answer to my needs! As a contractor I have very good pricing on silicone caulk. In fact I routinely use a product I can't wait to try. I will email epbot the results of my trials with it.
Very nice video, and I learned something unusual today, many thanks! The fact that people are writing passionate dissertations on the properties of silicon shows how much interest your video has generated. Well done! Very nice work. Some great tips from others below too. What a great thing to pool our knowledge like this. But it all started with your video!
This is an interesting technique although I don't do this sort of craft. I saw another comment about making a dome. I also think that if you made a half-ball out of the silicon initially, it would allow air to escape rather than being trapped by placing the object flat into the silicone. A slight vibration motion as you press the item down would help the silicon migrate to all the areas and allow the air to escape. I may give this a try myself. Thanks.
Thank you for that, very nicely explained, l bought the silicone today & tried it out, l found it very easy, inexpensive & had good results, thanks again for sharing your experience. 👍
Excelant video. I am definately going to try this. Have you ever tried making a mold using the caulk mixed with corn starch ? You just incorperate as much corn starch in with the silicon as possible and eventually you end up with a mixture about the cinsistancy of silly putty that you can pick up with your hands to work with.
Caulking guns have a metal wire on them that you can fold out and use to perforate the foil seal inside a tube of caulk, that way you don't get your screwdriver end coated in caulk.
Ive done some 2 part mold making using the expensive silicone supplies and this concept caught my eye. I believe your results, which were not bad at all, could be improved by changing your application technique. With one sided items like you are experimenting with you compromise the level of detail by pressing the item into the mold media and making those small adjustments to level or further embed the item. Try mounting the item on something non stick and pressing the mold media over/down onto the part. That way you never mash the part in too deep nor do you make thicker parts than wanted because you can never go too deep. The owl pin would have retained the open holes in the background doing things this way. Not a bad quick alternative to the real stuff!
Important! The soap you use must contain glycerine in order for it to catalyze the silicone. Lol I started with dish soap but ended up using my shampoo because it was the only soap in the house with glycerine.
So is it just the glycerin itself that is needed so you could use pure vegetable glycerin? Also to prevent the silicone from sticking to your gloves out of the water try dipping your hands in your gloves in isopropyl alcohol, it will help keep it from sticking to your gloves, if it starts to get tacky reapply the alcohol to your gloves.
These are quite impressive.... the ones that didn’t come out ‘so great’, just appear to be aged, more ‘antique-y’ lol.... I have that exact same owl head, it came off of and old keychain... this is so do-able and your video is very good, the tone of effort shows. Can’t wait to check out some additional videos of yours. Thank you for sharing this with us.. take care.
Way cool, never saw this method before.... have seen the protoputty (similar idea silicon and corn starch). Have some do-dads I want moulds of for other props. Have to try this method as well.... always willing to try a new way as it might suit a specific need :)
To help with getting the finer details you should think about gluing the pieces down, make a border of some kind then press the silicone on top of the piece. Also it's better to do it in two steps. First pull some silicone off the mass and firmly press it into the finer details then put the mass of the silicone on top and firmly press it on starting on one side and moving to the other side then when all the silicone is in press all at he same time with something that fits almost perfectly in between the borders with I tiny gap around the edges to let air eacape. This works best with flat back items. If you have uneven objects you will need to use something like oil based clay to build up the back side of the objectso it sits flat. This is mostly used for a two part mould.
Thank you for taking the time to make your video . It was very informative and creative . I definitely want to try that in the future. It's a slow wet day on the Mississippi gulf coast that's how I found your video thanks again,😀
Nice video. I fully can recommend getting a small 10 oz. container of Composimold for this type of mold making. It's completely non toxic to handle and use -- even food safe -- and is reusable forever! Just melt and pour around blank. For smallish stuff it's the answer if you can get it. Casts in perfect detail from anything from silicone, resin, to cement. Not spons.
I think it would help to keep the shape of mold and some of the definition of the casting if you place the silicone into a container , soap dish or spray can lid. When you press the item into the silicone mold it will not deform.
"You could pipe this with a piping bag" Yup! The Sweets Deco/Decoden community has been doing this for years. It's called Whip. Silicone makes some really pretty icing and you don't need the soap mess to do it either. It can be as simple as buying a small tube of silicone (that doesn't need a gun) and taping an icing tip to the tube's mouth and boom instant creme! You should peek around decoden videos to see some cool ways of sprucing up silicone. Like mixing paint in to tint the colour or adding glitter to clear silicone with a hint of paint to make beautiful pastel glitter whip.
This is a great tutorial. Thank you for uploading! I think I might start collecting tiny things to turn to silicone molds. I love the owl and snowflake. The coin you made looks kind of old and antiqued. The non-detailed parts just add to that! I have a few questions. Is this silicone food-safe or is food-safe unfolded silicone available for a similar craft? Can you please do a tutorial for making silicone molds of 3D objects such as a crystal wand or a doll’s head? Can you also show us how you mix and pour resin without the dreaded air bubbles?
This hardware store silicone I'm using is NOT food-safe, but I've been told there is a food-safe version. I'm sure that's a specialty thing online; you'll have to ask Google. :) 3D objects require a 2-part mold, which I've never tackled - but maybe someday! If you're using clear resin, then pass a flame from a candle lighter over it; pops the bubbles like a charm. Casting resin doesn't have the bubble problem nearly as much, but make sure you pour it slow, and fish around the mold with a toothpick to make sure the resin has reached every little nook and cranny in there.
I’ve not seen the soap and water method before. Thanks for that. I’ve used the Grant Thompson (King of Random) method with cornstarch and food coloring. Works well.
This is cool idea. Just a suggestion, when removing the silicone from the water should put in a disposable container and only then put the part that will mark the mold - purpose? have a well-made and neat mold and there is no tendency for the mold to widen when the piece is laid
16:45 it miss on on details because you pushed it horizontaly down in the silikone, trapping air between the part and the silicone. If you point the silikon up, before pressing down, the air could kreep out beyond when getting gradualy sidewards contact with the silicone nice video!
Interesting video and comments, thanks for posting. I'm a tad confused by the terms, however, because commenters tend to use mold, mould, silicon and resin interchangeably. For the following I will use the English spelling of "mould" to refer to the shaped mass of silicon into which the "resin" is poured to make the part. I need to make a replacement knob for one that is missing on an antique radio. The originals were made of plastic, are cylindrical in shape with ridges down the side for better grip, and are the color of light wood. They are also drilled from the back to accept a 1/4" diam shaft. From what I've read so far I think I need to: 1. Use silicon caulk (acetic acid variety), cornstarch, water and dish soap to make the mould. Does the cornstarch replace the water or the soap (this point is unclear in the comments)? 20% to 60% by volume seems to be the recommended amount so I assume that means it is to be mixed directly into the silicon in a cup of some sort prior to being kneaded in the soapy water, is this correct? Can I further assume that cornstarch can also be brushed into the mould cavity to serve as a resist prior to pouring in the resin? 2. What resin should I use to make the part? The resin should be hard and durable, like hard plastic, and not become brittle in time. Is the stuff you use the same as epoxy glue or is it more like the stuff brushed into fiberglass cloth for covering boats? 3. Can additives be put in the resin to strengthen the part? I know that cornstarch is used to stiffen the mould, can it also be put in the resin to strengthen the part? Could an alternative like glass micro-balloons available in hobby stores (normally used to make strong yet light structures for model airplanes) be used instead? 4. How can the resin be colored? I'd like to match the original light-brown color as much as possible without resorting to paint. I have no interest in coloring the mould, which I think caused some additional confusion in the comments. I live outside the US so I will have to find local substitutes for your usual brands, which makes your use of "common household items" very appealing. Thanks for any guidance you can give!
Sincerely Yours Hi, Sincerely! I’m not the original poster of this video, but I think I can offer a few things that may help you out with your project. 1). As this video doesn’t use the cornstarch method, but still produces a good quality mould, I would skip the cornstarch, as it just adds one more layer of cost and complexity to a relatively simple and straightforward process. Since the part you are trying to reproduce is relatively small with almost no amount of overly complex detail, stiffening the mould would serve no real purpose. If you were planning on going into business producing these vintage stereo knobs on a mass scale, I would understand wanting to make strong durable moulds, but it sounds more like you are just making a one-off project, so the method shown in this video should do nicely. Likewise, for the same reasons (and more), I would not add anything to the resin to strengthen it. A stereo knob doesn’t have a whole lot of force applied to it. If you were making parts for the space station, I’d say go for it. 2)., 3). & 4). Any commercially available 2 part epoxy resin made for casting should work well, but I would steer clear of using epoxies sold as adhesives, as they tend to be thick when mixing, which makes it more difficult to remove air bubbles. As for mixing, follow the manufacturer’s instructions and don’t add any additional ingredients, as this will affect the way the epoxy sets up (or more likely, fails to set up). An exception to this is that you can add a pigment to the resin, just make sure that the pigment you purchase is compatible with the resin you use. These pigments are available in a wide range of colors. When mixing, stir slowly to avoid air bubbles, as these will also affect the final outcome. What I would do is make several moulds, using the original knob to make them one at a time. This way, you can mix a larger amount of resin, which aids in avoiding air bubbles, and pour several new knobs at once. This will allow you to pick the best looking knob of the bunch, and also gives you a few backups if drilling the hole for the shaft doesn’t go well on the first try. Do not dust the mould with anything, as the silicone will release nicely from the resin without it, and the dust would affect the final outcome of the part. I hope this helps. Best of luck with your knob!
@@mrimmortal1579 Thanks Ben, all sound advice. Not mentioned in my post (because I didn't know it until just now) is the fact that I'll have to drill a side hole as well for a setscrew to hold the knob onto its D-shaped shaft. Not a difficult task but it means that whatever resin I use will have to be tappable, or use an insert of some kind if I can find one. Making several knobs is therefore good advice as well. Thanks again.
This is called Condensation curing.With Condensation curing you either have a surplus water molecule or acetic acid (vinegar). Latex can inhibit the set of silicone. I was in R&D in the1970`s using Addition cured silicone.which is far more accurate.This was in respect of Dental impressions. O course this was sent to a Dental Laboratory to be cast in Plaster-of-Paris.It was also used to cast using epoxy resin with a high filler.:)
Overall a great presentation, one thing you should mention is that it has to be 100% silicone with no anti fungal additives. otherwise it may stay a sticky mess. Also if you want super fine detail you can thin out the silicone with something like MEK. Its quite a nasty solvent so do outdoors or wear a proper mask.You can then bush on a thin layer and once that is set you can apply the rest of the silicone normally.
Can you please make a video of you painting the resin molds? The spray paint and the acrylic? By the way im new 2 ur channel this is the first vid i saw n i am lookn 4ward 2 see more of ur vids
Funny. I was going to tell her the same thing. It's a long push pin attached to the actual glue GUN, for construction workers. I have 3 sons that do construction, they showed me. Saves time going to find a wooden skewer from the kitchen. After it dries on the pin don't forget to pull it off.
No here in Australia. All caulking/silicone/glue tubes like this I have ever come across come without nozzles, and just have a nipple to cut off, then screw on a nozzle, which can be removed so the tube can be sealed with a cap.
Thank you, Lady! This is incredible. And all the kind people who wrote in adding advice? Wonderful. I'll use this with my polymer clay. One question. The cornstarch method smells pretty bad and I do that outside. Does the water method have a smell? Thanks again!
Soap is not acting as a catalyst but as a slippery agent😊 but by removing the acetic acid from the silicone it allows it to rapidly set. Great for mould making
If you look around the caulk gun, most of them have a little metal rod on a hinge attached that you can use to puncture the tube of caulking. Keeps you from getting a bit of caulking on the screwdriver, or needing one handy at all. ;)
Flattening the silicone much thinner, and pushing it down over the object can pick up more detail, but can something not pick up any detail, you have to really careful to work it into all the crevices. Alternatively, if you're pushing the object into the silicone, fill a container, or if you don't have an appropriate size - make a box out of Lego bricks, soap or powder the Lego first, so the expansion of the silicone is restricted, and forces the silicone into every detail.
I waa going to suggest holding a flashlight under the mold shining upwards to show the detail of the mold when you pulled the items out. Maybe like a colored light or black light. Thank you for the ideas.
Excellent tutorial, thanks very much! I’ve been spending ridiculous amounts on silicone molds and it has cost me a fortune. I know what I’ll be doing now! How long do you knead the silicone for, and what temperature does the water have to be? Cheers, Sean
Omg thing that I found that works is instead of pushing the object into the silicone, lay the object down, then push the silicone onto the object. This gives the final a smooth backing and keeps the thickness very close because it doesn’t “roll” over the back of the object. Plus you can put a little more pressure on the silicone and force more air out resulting in higher detail. Nice job! The owl was my favorite
Thanks that's really helpful tip.
I was going to say, lay it down too. I've made lots of moulds this way. I redo furniture and lots of the scrolls are either cracked or missing so I use the original to make copies. Waaaaay cheaper than buying ready made 👍
That only works if you have a flat back, though. The pins/brooches she moulded wouldn't work that way
Thank's Uke.!
@@poisonedflowers Just an idea: prior to casting non-flat-back'd items, mold an actual back onto the item to be molded(?)
Just a note to clear something up for people. Acetic acid curing silicon (the type of silicon used here) does not get accelerated by dish soap. The soap does nothing other than stop it sticking to your hands.
The acetic acid in the silicon reacts with water to cure/set. If you read the tube you will see something along the lines of "cures with moisture from the air".
So your dish soap does not matter. What matters is mixing the silicon correctly to get the water into the silicon and trap it. The soap does not help to do this.
Problems you may run in to with this method.
1. You bought a silicon that does not have acetic acid in it. It is easy to figure out which ones do. Either it will say so on the tube, will read "cured by moisture..." or you will smell a harsh vinegar smell from it.
2. You did not mix in the water correctly which potentially trapped internal sections without any moisture to cure the silicon for larger chunks. Or you did not mix in enough to allow for fast curing.
Personally the better method is the corn starch method. Why?
1. it is more controlled and easier for a novice.
2. the corn starch adds volume to the silicon. If you silicon is far more expensive per gram than your corn starch then it makes sense for doing many molds.
3. it is easier and cleaner to work with since your hands don't get covered in silicon and you don't need gloves at any point. Adding the corn starch makes a more tough mold. You get slightly less spring to it (about 10% less spring). But the strength goes up (by a good 50-100% based on weight squish and pull tests, but varies based on how much corn starch you add). This is good for certain applications where you need a tougher rubber.
4. adding corn starch helps it to release easier from rough surface molds. For example a 3d printed mold can be hard to remove from something with the water only method. The cornstarch method helps with release when set.
5. It is easier to know when a corn starch and silicon mold is ready. It self releases from surfaces and sets uniformly.
6. The corn starch gives you the ability to make 100% opaque moldings. For example, if you had a plastic mold of something and you wanted it made of silicon and be opaque you could do it with corn starch.
7. I find you get greater mold resolution from the corn starch.
8. Corn starch silicon is easier to control the sizing, lip etc.
A great example of putting some of these benefits into place would be creating a silicon foot for a subwoofer. They are heavy so you need that extra strength. Otherwise you would end up with a much larger and slightly more ineffective at sound dampening silicon foot. You could also make it opaque to hide it or make it stand out. For example, a solid black or white foot. Both would be hard to do with the water method. Requiring a lot of ink which can be expensive (especially whitening ink).
I am sure I am forgetting or don't know some more benefit's. However I am sure that sums it up well.
Can you make a 2 part mold this way? For a cylindrical toy object. Perhaps using 2 tubes fo silcone for each mold part? Should I try this?
Ryan Spencer hi. Yes you could do that. How much silicon you would need is very specific to how large the cylindrical toy is however. Just remember a tube of silicon does go a long way. Especially since it increases in volume with the corn starch.
Also remember that the more corn starch you add the stiffer and harder to compress the mold will be. Now specifically the biggest decision/issue you are going to have is what type of filling methods you should use. There are quite a few ways. Some more suited to certain things than others. Parts that must be solid with no seam. Not even a slight seam. Then you will want to look up "block molds" on UA-cam. You will find they use liquid silicon. But with a slightly smaller amount of corn flower it will be easy to mash it into whatever container you use. And I do suggest using a container. Something roughly the shape you are going for. Or if you can't do that. Just make sure the walls around what you are making a mold of, are really thick. 2-3cm or about an inch. At the least.
You need it thick enough to be able to hold the weight of the filling you are going to put in and also to be able to be demold without breaking. If you do go with the block mold then you need to make sure you add a spout to fill the mold.
Otherwise if a seam is not an issue then go with a 2 part mold or a half mold if you part if symmetrical. Look up punished props academy on UA-cam. He does silicon molds very well. There is a Tested video on UA-cam as well with Bill from punished props where they did a lightsaber. They used liquid silicon. But if you kind of use similar methodology by making a block and then squishing your part into it then that will work.
Really it depends on your model. Feel free to message me if you need some more help.
Martin B, well done. Thanks to your overly precise, lengthy & acurate comment I am forced to "like" this video. This, will enable me to find your comments & instructions again.
brr johnsonlol. no problem. If you need to know anything else just pop me a message. There is always something new to add. New techniques and such.
do you have a recipe for the cornstarch and silicon mould that you could share?
Awesome! I'm a preschool teacher and my students LOVE painting plaster of Paris! I was having such a hard time finding appropriate molds...now I can just make my own! Thank you!
Have kids bring their favorite objects from home (more than one) then give them as a Valentine gift or Christmas ornament. Put a piece of a plastic straw in to keep a hole open for a cord, rope, chain or ribbon.
Excellent video. I've done set design work at a community college for degree credits, and there was nothing like this. It's a great way to borrow items, and create the props with realistic texture for the actors to use. I've known about these techniques, but only helped out with them on jobsites for construction, using the silicon to mold parts for all different kinds of construction or reconstruction. I've even seen it used to restore old detailed work, and been taught how.
When you are trying to get detail, the key point you have to remember is "consistent and constant weighted pressure". This is where dowels or something similar would come in handy with your coin or almost any mold.
Also, it's best if your molds are "Contained" or bounded by something with firm substance. The widest bottle cap or jar lid you can find would work. The reasoning is that you don't want the mold to get too soft around the object in some places, you want it to be firm and equally so, all over the entire mold surface. That way, when the object you're molding is placed within, the silicone gets compacted instead of spreading away, putting back pressure on the object and filling into the detail rather than spreading flat away from it. When you get a flat plastic piece the same size as the inner container, you can utilize that. By placing a weight on top of the center, you allow it to press the object into the mold when first making it. If you use clamps, it may be necessary to use four in direct cross, two exactly opposite one another, to keep the flat even. Again, this compresses the silicone, and pushes air bubbles around the detail out of the way. When you fill in the resin, you should also put the plastic over and put a small weight on top. This will maintain the firmness of the mold, and the resin will set with greater detail.
There are some other tricks that, when used together with the above, allow you to make a two-side recreation, using only a clamp to hold two sides together, allowing for the material to dry as two sided, with only a little excess in a few places. With little work, excess is removed, keeping the details.
If you cut a slice into the mold at the outer edge, with a ruler or something similar, and use the same implement on an opposite side, you can align a two sided mold later, making a two sided object with the sides aligned. To do this with many molds, you could use the same ruler or object for making the silicate molds, and the same lids, with a slice taken out. You can use similar lids, slightly cut away, but aligned the same way, for resin setting with single or double-side molds.
Great explanation
Very detailed instructions, thanks
Such a great video, i come back every now and then to refresh on this and it never fails
I use the GE brand 100% waterproof all purpose clear silicone 1 caulk to make my molds - both soap and cornstarch methods, depending on the application. Recently i mixed in a few drops of glycerine with a little acrylic paint for glow in the dark and blacklight glow molds! I plan to try talcum powder instead of cornstarch - its chemical composition should react with acetic acid with h2o as a biproduct.. might make for an interesting race against the cure clock!
Here's some notes I've taken:
The retardant is the acetic acid in these 'condensation cure' type silicones - slows the cure, thins the caulk, vinegar smell during cure.
The soap is to wash away the retardant and make the silicone pliable, knead in water for quick cure.
Cornstarch/Glycerine also speed the cure by distributing moisture, however the smell is much worse if the retardant was not washed out, prior.
Glycerine adds elasticity, much faster cure. Cornstarch adds rigidity, next fastest cure. Soap adds pliability, lightens and allows for moisture incorporation.
Refrain from casting metal, oops, as the acetic acid will react with it - discoloring the mold, worsening the odor/fumes.
Refrain from using latex gloves, enamel paint, anything with sulphur - inhibits cure, stays sticky icky.
Now go, and become the mold making guru you were meant to be! 😂
*j.g i80
"Refrain from using latex gloves, enamel paint, anything with sulphur - inhibits cure, stays sticky icky." All of the molds i made left the resin pieces very sticky...Mess! what did i do wrong! the pieces i used was metal!
This tutorial is awesome! I do body casting for fun and profit. All my pieces are one of a kind, but making a mold this way is SO much easier than the moldmaking materials that are sold. I've GOT to play with this!
Becky Jamin I'm hoping to make a mold that can withstand up to 520 degrees to make a ring
That's useful to know about caulking. I'll give that a whirl. Thanks for sharing.
For future reference: in order to get fine details in the centre of the star ornament, it would be best to glue the original (face up of course) to a smooth backboard. Mold the silicone into a ball with a slight peak. Press the peak into the deepest recess in the centre and then press the silicone ball over the whole, flattening it onto your pattern. This ensures that the recess is filled and the air is forced out (it was trapped air that prevented the silicone from making firm contact with the pattern). Peel the mold off when hardened. This will give the mold a clean flat edge, allowing for a neater casting.
There. I hope this tip will be as useful to you as your tip is to me. Thanks again.
Instead of pressing the moulding flat, make a dome... So when you press down - Like with the snowflake - the star in the middle hits the mould first and then you press it down to create the mould ;)
great tip thank you
That's what I was going to say. The star in the middle of the snowflake clearly got messed up by trapped air. This was also the case for the coin, and the lettering on the Hufflepuff pin.
Great tip! ❤️
@Figueroa Rury Laquinta uncultured swine
I'm thinking I can duplicate missing hardware off antique dresser I've had since childhood to help restore it. I'm going to try it. thanks for video. cool!
Yes, this should work! I've done exactly that to repair a broken antique lamp piece, though I used a store-bought silicone putty at the time. You can see those results here on the blog, plus I share some tips on how to attach it to metal and repair the seams, if you have any: www.epbot.com/2017/03/molding-casting-to-repair-worlds.html
I was thinking the same thing. We have a Martha Washington sewing table that is missing a drawer knob. I was going to mix sawdust with glue and put it into a mold.
Well that was fantastic, I never new that we could make your own molds with silicone, TFS, Cheers Anna.
Cool tutorial, and I like the molds you and your husband painted! Can think of lots of things to make with the recipe, like molds for furniture, charms for journals, pens for gifts. Thanks so much for doing this!
Thanks for demonstrating this! I needed a molding material to recreate a wood detail that is missing from an old piece of furniture. Just what I needed!
I am doing exactly the same!
Ditto! Except it’s to repair a buffet leg that the dog chewed on!
Great video. You are really great at giving the viewer good clear instructions. I hope you don't mind me giving you a little advice from my own experiences with molding. I do believe though that with more time and practice, you can get more details from what you are taking molds of. I found that laying flat backed on a smooth surface and then gently pressing the silicone onto the top of the item to be molded helps to get a better-detailed mold and press it down around the edges so you get a nice smooth and flat top to the edges of the item being molded. Then use something flat to press down from the top of the silicone, to form a flat bottom to the mold. It also helps if you can try and make sure that the surface of the silicone that will be making contact with the item is as smooth as possible too so you're not introducing extra textures that shouldn't be there. You could also place the item into something like a cookie cutter and do the same as I mentioned above, inside the cookie cutter to get a more uniformed shape to the edge of the mold. Any, I really hope this is of use for either yourself or any of your viewers. All the best, Diane xx
Oooh, great advice! Will definitely keep these in mind for next time, thanks.
great advice from both of you! Thank you
balacollie ⬅️ I was wondering if anyone was going to address this "reverse" process of pressing the media onto the mold object & using a barrier ring container for compressing & leveling the mold itself for greater detail & uniformity. The next step is making mold-halves for 3-D objects that can be banded together. Thank you for bringing this up! Greatly appreciated!
I would really like to know if there is heat generation during curing, as I would like to make 4" x 1-1/2" cylinder candles... Suggestions?
The advantage of working upside down is also the top of the mold is flat. Particularly useful when filling the mold with plaster of paris and striking the filling off to produce flat backed roses for repeat use along a cornice, since they need to all be exactly the same depth.
I use silicone nearly every day. I would never have thought of doing that with it. Try wax polishing the objects before putting them in the silicone mould. The better the polished shine the better the copy is. It's the wax componds in soap that stops it sticking. It releases from the mould easier with out as much damage to the fine detail. Cool video. Thank you.
What kind of wax?
Holy crap girl. That is unbelievable and sooo simple and do-able. So quick for that great of results.
I was going to make a silicone mold of a wagon wheel. I'm glad I found this video because it will make the job a whole lot easier.
Hello...thanks so much for making this video. I was always trying to find a way to add 3D "ephemora" to my art projects...and this has solved the issue. I am making an abstract painting for a mechanic friend and was able to mold some bolt heads and create some 3D bolts to add to my project! Thanks again. Ignore the haters. They exist, but can never keep an artist down. We already have beaten so many odds just to make art, and sell art, and be recognized as artists, that no hater can get us get the best of us! Good luck to you and your lovely assistant.
This was one of the best step by step tutorials I've ever watched. The results were very impressive👍❤️
Super informative, great visual tutorial, and I'm really glad you showed what the end results could look like when detailed. A lot of the time that crucial step is left out and leaves the tutorial feeling unfinished. Great Job!
Wow! Thank you!!! On a budget this is awesome for a project I have been pondering and trying to figure out how to do this without spending time looking and finding what I need... perfect!!!! I already have everything I need at home!! No more shopping online for the answer...I found it in this video!! Again, THANK YOU!
Thanks for showing this. I have been trying to figure out a way to do a mold for a replacement part on an old doll. I'm going to give this a shot. Thanks again
I can't wait to try this...I do a wide variety and can't find molds of certain things so I have a starting point. Thank you for the great video.
Wow! This is a great tutorial! I can't tell you how excited I was to learn how to do this -and, I don't even do this kind of stuff! A++ from me! 👍👍👍
This is very cool. I work with polymer clay and I'm seeing all kinds of possibilities!!!! Thank you.
I’ve watched a ton of videos trying to decide if I wanted to try the dishwashing detergent with silicone or the cornstarch method. Your tutorial is by FAR the best video of them all.. Definitely the most helpful, and you sold me! I have been sitting here for a week with all the ingredients trying to decide. I wish I had watched your video to begin with. Thank you so much! I am subscribing to your channel now. 😘
Miranda, me too. I've watched videos on both methods and have all of the ingredients trying to decide. I'm going with the cornstarch method because someone stated above that it is a little more rigid than the soap version. I will be making texture plates for polymer clay, so the silicone "mold" will have to be flat and relatively thin. BTW, did you see the video with the cute hunting/para-military dude doing this with silicone and corn starch?
I just wanna say,, great demo,, definitely gonna try this out.
I've cast with smooth on before,, mostly two part molds. I wanted to touch on that because the two part mold process can be used on a one surface piece.
So,, if you revisit this like the seahorse or hufflepuff pin you could have clay be your base,, mush the back of the pin into the clay and make it flush then place your silicone over it yielding cleaner results.
THIS IS SO COOL! The owl is my favorite!! Great job with the video.
You did a great job ! I worked making silicon molds omg they take hours to do plus hours to cure. Then the special equipment to do it all. I took a master mold making class just to make them. Your way is fast easy to do I love it !
perfect. thanks. Ive used commercial mold material but since I don't qualify at professional volume for discounts, it becomes very expensive. This is a great answer to my needs! As a contractor I have very good pricing on silicone caulk. In fact I routinely use a product I can't wait to try. I will email epbot the results of my trials with it.
Very nice video, and I learned something unusual today, many thanks! The fact that people are writing passionate dissertations on the properties of silicon shows how much interest your video has generated. Well done! Very nice work. Some great tips from others below too. What a great thing to pool our knowledge like this. But it all started with your video!
Water is actually the catalyst for silicon. I think the soap is a lubricant. If you want your mold more firm add corn starch.
can the molds be heated for sculpy?
The most beneficial & informative video I've seen on making molds!
I love the results of the coloring! The possibilities are endless.
I love that you can make your own silicon moulds. Thanks for sharing this great vid.
This is an interesting technique although I don't do this sort of craft. I saw another comment about making a dome. I also think that if you made a half-ball out of the silicon initially, it would allow air to escape rather than being trapped by placing the object flat into the silicone. A slight vibration motion as you press the item down would help the silicon migrate to all the areas and allow the air to escape. I may give this a try myself. Thanks.
Thank you for that, very nicely explained, l bought the silicone today & tried it out, l found it very easy, inexpensive & had good results, thanks again for sharing your experience. 👍
This is super! Another cool thing to do with my art class!
The best video on making molds,can't wait to make them to be use on my cake decorations. Thank you so much.
You saved me like a grip of money
I love your silicone recipe for tinting and they came out pretty good over all. Thanks for sharing. New sub
Excelant video. I am definately going to try this. Have you ever tried making a mold using the caulk mixed with corn starch ? You just incorperate as much corn starch in with the silicon as possible and eventually you end up with a mixture about the cinsistancy of silly putty that you can pick up with your hands to work with.
Caulking guns have a metal wire on them that you can fold out and use to perforate the foil seal inside a tube of caulk, that way you don't get your screwdriver end coated in caulk.
Ive done some 2 part mold making using the expensive silicone supplies and this concept caught my eye. I believe your results, which were not bad at all, could be improved by changing your application technique. With one sided items like you are experimenting with you compromise the level of detail by pressing the item into the mold media and making those small adjustments to level or further embed the item.
Try mounting the item on something non stick and pressing the mold media over/down onto the part. That way you never mash the part in too deep nor do you make thicker parts than wanted because you can never go too deep. The owl pin would have retained the open holes in the background doing things this way.
Not a bad quick alternative to the real stuff!
Important! The soap you use must contain glycerine in order for it to catalyze the silicone. Lol I started with dish soap but ended up using my shampoo because it was the only soap in the house with glycerine.
So is it just the glycerin itself that is needed so you could use pure vegetable glycerin?
Also to prevent the silicone from sticking to your gloves out of the water try dipping your hands in your gloves in isopropyl alcohol, it will help keep it from sticking to your gloves, if it starts to get tacky reapply the alcohol to your gloves.
I wish instructables would bring back the app. I loved that app.
Very nice clearly explained video with a pretty cool trick with silicone, many thanks just what I was looking for, cheers Ross
Those came out great, I can hardly wait to make some molds myself.
These are quite impressive.... the ones that didn’t come out ‘so great’, just appear to be aged, more ‘antique-y’ lol.... I have that exact same owl head, it came off of and old keychain... this is so do-able and your video is very good, the tone of effort shows. Can’t wait to check out some additional videos of yours. Thank you for sharing this with us.. take care.
Thank you. This video showed me what I wanted and more! Very Good job!
Oh Heck Yeah!!! Awesome video and thanks for sharing!! Subscriber from NW FL.
Good job. I will try making a mold of my candles.
Way cool, never saw this method before.... have seen the protoputty (similar idea silicon and corn starch).
Have some do-dads I want moulds of for other props. Have to try this method as well.... always willing to try a new way as it might suit a specific need :)
What a fantastic idea. I've been buying silicon moulds and i use uv resin. Using your idea we can make copies of anything. Thanks for the great video
To help with getting the finer details you should think about gluing the pieces down, make a border of some kind then press the silicone on top of the piece. Also it's better to do it in two steps. First pull some silicone off the mass and firmly press it into the finer details then put the mass of the silicone on top and firmly press it on starting on one side and moving to the other side then when all the silicone is in press all at he same time with something that fits almost perfectly in between the borders with I tiny gap around the edges to let air eacape.
This works best with flat back items. If you have uneven objects you will need to use something like oil based clay to build up the back side of the objectso it sits flat. This is mostly used for a two part mould.
I don't know if someone pointed out, but you can use a muffin tray to pour the silicon so it won't spread out as much.
Magaly Santiago I have a question doesn't isn't sure it's the silicone that she's using toxic cuz silicone has acid in it that can burn your hands
@@sunshinemurphy1493 That's the _acetoxy_ (vinegary) type silicone.
Oh man, I'm so excited to try this for my mini brick molds! 😄
Thank you for taking the time to make your video . It was very informative and creative . I definitely want to try that in the future. It's a slow wet day on the Mississippi gulf coast that's how I found your video thanks again,😀
That owl came out so great!
Nice video. I fully can recommend getting a small 10 oz. container of Composimold for this type of mold making. It's completely non toxic to handle and use -- even food safe -- and is reusable forever! Just melt and pour around blank. For smallish stuff it's the answer if you can get it. Casts in perfect detail from anything from silicone, resin, to cement. Not spons.
BEST video, and thank you for doing a complete video.
Helpful video. Thank you! I just wish I could see the whole process including filling up stage and painting.
Cool facets on the Owl eye.
I think it would help to keep the shape of mold and some of the definition of the casting if you place the silicone into a container , soap dish or spray can lid. When you press the item into the silicone mold it will not deform.
Pretty sweet how well that worked!!
"You could pipe this with a piping bag"
Yup! The Sweets Deco/Decoden community has been doing this for years. It's called Whip. Silicone makes some really pretty icing and you don't need the soap mess to do it either. It can be as simple as buying a small tube of silicone (that doesn't need a gun) and taping an icing tip to the tube's mouth and boom instant creme! You should peek around decoden videos to see some cool ways of sprucing up silicone. Like mixing paint in to tint the colour or adding glitter to clear silicone with a hint of paint to make beautiful pastel glitter whip.
This is a great tutorial. Thank you for uploading!
I think I might start collecting tiny things to turn to silicone molds. I love the owl and snowflake. The coin you made looks kind of old and antiqued. The non-detailed parts just add to that!
I have a few questions. Is this silicone food-safe or is food-safe unfolded silicone available for a similar craft? Can you please do a tutorial for making silicone molds of 3D objects such as a crystal wand or a doll’s head? Can you also show us how you mix and pour resin without the dreaded air bubbles?
I was going to ask the same question, I'd love to know
This hardware store silicone I'm using is NOT food-safe, but I've been told there is a food-safe version. I'm sure that's a specialty thing online; you'll have to ask Google. :)
3D objects require a 2-part mold, which I've never tackled - but maybe someday!
If you're using clear resin, then pass a flame from a candle lighter over it; pops the bubbles like a charm. Casting resin doesn't have the bubble problem nearly as much, but make sure you pour it slow, and fish around the mold with a toothpick to make sure the resin has reached every little nook and cranny in there.
the long steel rod under the frame of the caulking gun is for puncturing the mylar seal in the caulk tube
Thank you for this video. I loved it, it was fun to watch. Omg, molds are sooo expensive. Thanks.
Great video! Thanks for all the info. I will definitely be trying this out myself.
I love the reverse "My lovely assistant John"
I’ve not seen the soap and water method before. Thanks for that. I’ve used the Grant Thompson (King of Random) method with cornstarch and food coloring. Works well.
Great job! Great results! Thx. Gonna try w/ some 3D prints!:)...
I had no idea you had a UA-cam channel! Just saw the Epbot logo!
This is cool idea. Just a suggestion, when removing the silicone from the water should put in a disposable container and only then put the part that will mark the mold - purpose? have a well-made and neat mold and there is no tendency for the mold to widen when the piece is laid
Manuela Mendonca
16:45 it miss on on details because you pushed it horizontaly down in the silikone, trapping air between the part and the silicone. If you point the silikon up, before pressing down, the air could kreep out beyond when getting gradualy sidewards contact with the silicone
nice video!
Thank you for a very detailed and informative video! Well done 😊
Interesting video and comments, thanks for posting. I'm a tad confused by the terms, however, because commenters tend to use mold, mould, silicon and resin interchangeably. For the following I will use the English spelling of "mould" to refer to the shaped mass of silicon into which the "resin" is poured to make the part.
I need to make a replacement knob for one that is missing on an antique radio. The originals were made of plastic, are cylindrical in shape with ridges down the side for better grip, and are the color of light wood. They are also drilled from the back to accept a 1/4" diam shaft. From what I've read so far I think I need to:
1. Use silicon caulk (acetic acid variety), cornstarch, water and dish soap to make the mould. Does the cornstarch replace the water or the soap (this point is unclear in the comments)? 20% to 60% by volume seems to be the recommended amount so I assume that means it is to be mixed directly into the silicon in a cup of some sort prior to being kneaded in the soapy water, is this correct? Can I further assume that cornstarch can also be brushed into the mould cavity to serve as a resist prior to pouring in the resin?
2. What resin should I use to make the part? The resin should be hard and durable, like hard plastic, and not become brittle in time. Is the stuff you use the same as epoxy glue or is it more like the stuff brushed into fiberglass cloth for covering boats?
3. Can additives be put in the resin to strengthen the part? I know that cornstarch is used to stiffen the mould, can it also be put in the resin to strengthen the part? Could an alternative like glass micro-balloons available in hobby stores (normally used to make strong yet light structures for model airplanes) be used instead?
4. How can the resin be colored? I'd like to match the original light-brown color as much as possible without resorting to paint. I have no interest in coloring the mould, which I think caused some additional confusion in the comments.
I live outside the US so I will have to find local substitutes for your usual brands, which makes your use of "common household items" very appealing.
Thanks for any guidance you can give!
Sincerely Yours
Hi, Sincerely!
I’m not the original poster of this video, but I think I can offer a few things that may help you out with your project.
1). As this video doesn’t use the cornstarch method, but still produces a good quality mould, I would skip the cornstarch, as it just adds one more layer of cost and complexity to a relatively simple and straightforward process. Since the part you are trying to reproduce is relatively small with almost no amount of overly complex detail, stiffening the mould would serve no real purpose. If you were planning on going into business producing these vintage stereo knobs on a mass scale, I would understand wanting to make strong durable moulds, but it sounds more like you are just making a one-off project, so the method shown in this video should do nicely. Likewise, for the same reasons (and more), I would not add anything to the resin to strengthen it. A stereo knob doesn’t have a whole lot of force applied to it. If you were making parts for the space station, I’d say go for it.
2)., 3). & 4). Any commercially available 2 part epoxy resin made for casting should work well, but I would steer clear of using epoxies sold as adhesives, as they tend to be thick when mixing, which makes it more difficult to remove air bubbles. As for mixing, follow the manufacturer’s instructions and don’t add any additional ingredients, as this will affect the way the epoxy sets up (or more likely, fails to set up). An exception to this is that you can add a pigment to the resin, just make sure that the pigment you purchase is compatible with the resin you use. These pigments are available in a wide range of colors. When mixing, stir slowly to avoid air bubbles, as these will also affect the final outcome.
What I would do is make several moulds, using the original knob to make them one at a time. This way, you can mix a larger amount of resin, which aids in avoiding air bubbles, and pour several new knobs at once. This will allow you to pick the best looking knob of the bunch, and also gives you a few backups if drilling the hole for the shaft doesn’t go well on the first try.
Do not dust the mould with anything, as the silicone will release nicely from the resin without it, and the dust would affect the final outcome of the part.
I hope this helps. Best of luck with your knob!
@@mrimmortal1579 Thanks Ben, all sound advice. Not mentioned in my post (because I didn't know it until just now) is the fact that I'll have to drill a side hole as well for a setscrew to hold the knob onto its D-shaped shaft. Not a difficult task but it means that whatever resin I use will have to be tappable, or use an insert of some kind if I can find one. Making several knobs is therefore good advice as well. Thanks again.
This is called Condensation curing.With Condensation curing you either have a surplus water molecule or acetic acid (vinegar).
Latex can inhibit the set of silicone.
I was in R&D in the1970`s using Addition cured silicone.which is far more accurate.This was in respect of Dental impressions.
O course this was sent to a Dental Laboratory to be cast in Plaster-of-Paris.It was also used to cast using epoxy resin with a high filler.:)
Overall a great presentation, one thing you should mention is that it has to be 100% silicone with no anti fungal additives. otherwise it may stay a sticky mess. Also if you want super fine detail you can thin out the silicone with something like MEK. Its quite a nasty solvent so do outdoors or wear a proper mask.You can then bush on a thin layer and once that is set you can apply the rest of the silicone normally.
Can you please make a video of you painting the resin molds? The spray paint and the acrylic? By the way im new 2 ur channel this is the first vid i saw n i am lookn 4ward 2 see more of ur vids
On the underside of your caulk gun there should be a wire on a screw, and that is for puncturing the membrane inside the caulk gun.
Funny. I was going to tell her the same thing. It's a long push pin attached to the actual glue GUN, for construction workers. I have 3 sons that do construction, they showed me. Saves time going to find a wooden skewer from the kitchen. After it dries on the pin don't forget to pull it off.
No here in Australia. All caulking/silicone/glue tubes like this I have ever come across come without nozzles, and just have a nipple to cut off, then screw on a nozzle, which can be removed so the tube can be sealed with a cap.
That owl pin is amazing.
What beautiful results! Very nice finishing work as well. What paint did you use for the metallic appearance? Is it sprayed or brushed on?
More than likely, the tool to punch the seal on the tube after you have cut the tip, is actually on the caulking gun laying flat against it.
Sometimes they are. Those cheapo ones like she's got though you usually have to find something or other.
Thank you, Lady! This is incredible. And all the kind people who wrote in adding advice? Wonderful. I'll use this with my polymer clay. One question. The cornstarch method smells pretty bad and I do that outside. Does the water method have a smell? Thanks again!
Yeah it reeks like vinegar, if it's the right kind of silicone :)
Soap is not acting as a catalyst but as a slippery agent😊 but by removing the acetic acid from the silicone it allows it to rapidly set. Great for mould making
Well Done! I feel like I could do this now.
Thank yoooou! I'm going to save so much money by making my own molds now :D
Can you use these molds for soap making?
I'm super impressed with your creativity and genuine curiosity.
Yes you can- another UA-camr did it and showed her molded soap result at the end. I'm sure you know that by now but just in case 🙂
this would be awesome for gallium molds, thanks!
Thank you for this tutorial. I make jewelry and this will be great!
i really like the coint.. they all look good.. thanx for showing it :D
If you look around the caulk gun, most of them have a little metal rod on a hinge attached that you can use to puncture the tube of caulking. Keeps you from getting a bit of caulking on the screwdriver, or needing one handy at all. ;)
Flattening the silicone much thinner, and pushing it down over the object can pick up more detail, but can something not pick up any detail, you have to really careful to work it into all the crevices.
Alternatively, if you're pushing the object into the silicone, fill a container, or if you don't have an appropriate size - make a box out of Lego bricks, soap or powder the Lego first, so the expansion of the silicone is restricted, and forces the silicone into every detail.
Awesome, thank you! Where do you get the resin material from?
Wonderful! Do you think if you dry brushed after you antique it, maybe you could pick up more of the details? Definitely going to try this! Thanks!
Great video! Thank you. Can’t wait to give it a try!!!
I waa going to suggest holding a flashlight under the mold shining upwards to show the detail of the mold when you pulled the items out. Maybe like a colored light or black light. Thank you for the ideas.
Excellent tutorial, thanks very much! I’ve been spending ridiculous amounts on silicone molds and it has cost me a fortune. I know what I’ll be doing now! How long do you knead the silicone for, and what temperature does the water have to be? Cheers, Sean