Composite Materials : Vacuum vs Pressure
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- Опубліковано 8 лис 2018
- This week I experiment with resin, cloth and other materials to see what works best for making micarta.
Video about the vacuum chamber:
• DIY Vacuum Pump And Ch...
Video about the pressure pot:
• Pressure Chamber | Res...
I found the pink silicone mold searching for "soap mold" and it's just about the right size for a handle blank.
The holder for the mold was designed in Fusion360 and 3D printed in PETG.
Thanks a lot for watching, I hope you liked the video!
Suggestions and comments are welcome.
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As others pointed out, you really want to use a vacuum bag. We do it with surfboards and it works perfect every time. Bag alone is not enough though, you also need a breather cloth and a peel-ply is very useful. Breather allows the vacuum to reach all parts of the bag and peel-ply makes it easy to detach breather from the part afterwards.
Both can be bought at places that supply composite materials, but you can also use an old blanket or felt material for breather, and ordinary plastic PE-LD bags or any other foil the resin will not stick to for peel-ply. You have to make many needle holes in the peel-ply foil so excess resin and air can move through it though. A large IKEA freezer bag can be used as a vacuum bag. Vacuuming time is very short with a small bag, even with the small fridge compressor you're using.
Stackup goes like this: first the laminations you're making, then peel-ply, then breather and finally the bag on the outside. Ideally you'll be able to ditch the silicone mould and just put everything in the bag. If you still need the mould, seal the bag first, put it all together in the mould and then apply vacuum.
To make it work you will need longer resin open time. Polyester resins usually can be mixed with less hardener to make the reaction slower. You can also make the layout faster by wetting many layers at once, pressing the excess resin with two rollers (like a pasta machine), etc.
With vacuum you should aim at around 50-50 weight ratio between resin and cloth (that is true for glass, don't know about old jeans :))
Vedran Latin- I thought the whole video was a joke until we got to the end. How is it folks are allowed to make videos when they have NO idea what they are talking about? I like your answer when do you share the proper instructions? At 72 me and my flip phone aren't about to try.
When you use vacuum for this process you must put the product into a bag and vacuum out the air from the bag. Makes a much tighter bound.
christopher lynn He did the same thing, but in a different way.
@@mindnova7850 You need a vacuum bag so it comprises the layers into a tight block, just leaving it in the vacuum chamber will not work.
@@mindnova7850 the flexible nature of the bag also applies pressure to the block, from the atmosphere outside, which doesn't happen with just a chamber
@@alextopfer1068 yep and you only vacuum the bag not the entire container, thus faster to vacuum out
The vacuum bag is what I'm thinking. Watch how Lamborghini makes body parts out of carbon fiber for their vehicles. They have a mould, which they lay resin and carbon fiber cloth into, paint more resin on, then put the whole thing in a bag. The air is vacuumed out of the bag, causing the bag to compress the resin and carbon fiber against the mould. This is all placed under vacuum into an autoclave where it is heated to a specific temp for a specific amount of time.
I believe that simply removing the air from a chamber to allow the resin and composite materials to set isn't sufficient enough. The vacuum bag method applies pressure to the layers of composite material and resin.
I commend Black Beard for this experiment, none the less.
Polyester resin has an exothermic reaction when mixed, this expands existing atmosphere dissolved in the resin. If you degas the separate parts resin and hardener before mixing it will help reduce the voids in the finished product when cast under pressure. I also use a rigid mold with a block that fits in the top and clamps to apply force to the mold. I hope this helps!
I wold comment the exact think.
The best way to do it. Grettings from Brazil 🇧🇷
Good videos, keep experimenting. I think Vacuum is only good when it's used to generate the pressure similar to how carbon fiber and fiber glass parts are made with vacuum bag
sadly that's exactly how this should be done. Mr. black beard is doing both methods wrong.
Hey. Nice work. I love your channel.
The way you are using vacuum and pressure, you end up with two very different processes.
The vacuum lessens the pressure around the part, which does two things: try to pull the tiny air bubbles out of the resin, but also, because the pressure is much lower around the part, it INFLATES these bubbles as well (like when you put a half inflated bubble in a vacuum chamber, as you pull vacuum, the balloon gets bigger; check it on youtube, or do it, it's pretty cool). Part of the problem with this is that not all the bubbles are able to make their way out, so, as the resin cures, you have many bubbles that end up stuck there. This is probably made worse by the fact that it's a composite; the bubble in a solution just float up as they get bigger while in a composite, the fabric gets in the way, so the bubbles have to go around the fabric, making it that much more difficult. It's more like blowing a balloon than pulling the air out.
With the pressure technique, you're doing the opposite: by raising the ambient pressure, you make all these tiny bubbles shrink, as the air around it compresses the composite, and when it cures, the bubbles are stuck there, but so small and compressed that they are hard to see. It's not perfect for inner structure, but it's better than the big bubbles from the vacuum.
Other people have mentioned that usually, composites are put in a bag, and vacuum is pulled from that. What you get there is like the best of both worlds; the vacuum pulls the air out of the piece, but because the pressure IN the bag is lowered, the outside air puts pressure ON the bag, and thus on your part.. you both suck the bubbles out from inside and press them out at the same time. You should try that out next; just make sure you don't suck resin into your vacuum pump (you should check out how to make a resin collector from a container between the bag and the pump)...
Use a block of lead to flatten the layers then both ways will work fine.
Amazing making! 👌👏
Interesting. Have you tried sandwiching between wood blanks and small clamps?
Great video, I respect what you have done here. Responded to people's comments. I always thought when making it it was layered and then applied pressure with a weight. Same with vacuum bags, the force of the bag squeezing it is more then just a vacuum, we are using the vacuum to create pressure.
spot on
@@thebottleproject2730 so with a solid vacuum chamber the chamber takes on the forces as, it's solid. It doesn't constrict in volume, take a plastic bag and a apply vacuum the outside walls create pressure to the volume inside and reduces, therefore squeezing the insides. Hope that makes sense.
@@thebottleproject2730 no paul , vaccum pulls out bubbles, sheer pressure can never do that, the single bast way is to bag it, and pull a vacuuum on the bag
@@jusb1066 put could pressure not push out bubbles lol
@@ifell3 no it does tend to shrink them, but vacuum pulls them out entirely, if you also put it in a bag, the bag squashes on the outside, double win! you actually put it into mould, then bag it, or it will push on all sides, squashing your thing out of shape
Composite materials are making by vacuum infusion. Put your material in polyethylene packet with two tube closed holes, after that make vacuum there through the one of tube hole. Put the second tube to reservuar with resin and open the tube. The resin should go to the packet through all of your material without leaving there any buble. Let vacuum pump work until all material will in resin. Close the tube with resin. And let vacuum pump work until resin stop come out from the packet. Swith off pump, close the second tube and let resin become a plastic. To make your result more accurate you can make pressure over the packet more than 1 atmosphere, use your pressure pump!
Sounds legit :)
В пакете сложно добиться ровной поверхности. Хотя идея хорошая. Плотность заготовки станет выше.
yep - basic "high quality" fiberglass boat building technique.
@@user-lh4bm1po7f это не идея, это академический метод производства композитных конструкций, а форму необходимую получают помещением заготовки в матрицу, но тут это совсем не к чему
Ну как бы согласен. выше уже комент оставили. меня другой вопрос интересует, залить большую площадь допустим столешницу с панорамой лучше сверху и вытравить воздух или способом стекловолокна, то есть вашим способом?! Опыта заливки нет пока, пока идеи и желания, а испортить не хочется.
This channel is one of the best examples why i love UA-cam!
Cool tests thanks for sharing! I'd like to see the same test again but I've heard of people using large magnets to compress the micarta... using the large magnets inside of the pressure or vacuum chamber might give you even better results! Thanks
very interesting stuff, thanks for explaining the process.
Amazing making
great experiment loved the idea be blessed
Interesting to see the differences in each systems.
I expect that putting a large weight on top before you put pressure or vacuum on it would get you a much stronger part
Try the vacuum in a zip lock bag with some peel ply and breather fabric.
It will squeeze the bubbles out and the fabric together.
Very very interesting. Thanks a lot I learned quite a bit from this very short video!
Thanks for the cool test and great thorough info! You should try using something like fine steel wool or a scotch brite pad and just compressing it with clamps!
Great job
Air pressure and vacuum chambers are far different than weighted pressure and vacuum bagging. I’m not familiar with the curing process you’ve demonstrated but I feel that the results would have been far superior for both methods if you had used weighted pressure and vacuum bagging for this experiment. Just my $.02
Gratitude for his excellent videos, always accompanying here from Brazil. Great tests on today's video and congratulations for all your work!
Big hug friend!
Oh there we go finally you talk!!!
perfect!
Really good examples and comparison between the two methods. I agree, pressure gives better and most consistent results when making all types of micarta. Even with the more expensive polyester resins, I find this is the way to go. A quick de-gas with vacuum works well, if you have adequate working time before pressurizing, but it's not usually necessary. Great video as always!
i like that cutter at the start, havent seen anything like it before if you ignore pizza cutters ofc, i just use stanley knives
Ficou muito bom , perfeito.
I find that simply applying physical pressure works best. I use a piece of aluminium bar the same size as the mould and drill small holes in it to allow excess resin and air to come out. Haven't had an issue with that method yet.
cool stuff! thanks
you always make cool videos
So nice
Love the explanation! Good luck on makeing the micarta. I just watched anothe video by Peter Brown from shoptime where the pressure pot also performed better.
Me gusta el video, no deja de ser el proceso de construcion con fibra de carbono con resina integrada que se utiliza en la industria aeronautica y para otra cosas cosas. fascinante.
I have had decent luck with a wooden form using wax paper with a wooden block on top and clamps to squeeze the material together. I then correct shape on belt sander. Works great for knife scales. Using the silicon molds you have and a block of wood wrapped in wax paper and clamped down should work great.
815k subscribers, well done bro you deserve very one of them. It wasn't too long ago you did a video for 100k. Congratulations on the success
The molds need pressure on them, such as clamps. This will eliminate many of the voids. Also, it works better if you add additional resin on each.
Vacuum is used mainly with thin resin like Cactus juice for wood stabilization. It takes few hours sometimes. Pressure pot is used for casting mainly. So methods are different and depends on needs.
Great video and I agree with your assumptions. Perhaps if you are able to mix up a slightly thinner resin it would extend the cure time and help in eliminating the bubbles - may just take a little experimentation to get the right ratio
When we used to build composite airplanes, we used vacuum molding. We used a release/peel ply against the part, a bleeder ply on top to absorb excess resin and then the vacuum bag. We left the part under pressure and rolled the mold into our oven to heat cure (we used epoxy resins). This results in very tight, voidless laminates that passed rigorous testing since these were fuselages, wings and canards for 4-place airplanes. Admittedly my experience with polyester resins in somewhat less- small boat hull and some surfboard repairs. I would think that keeping the micarta under vacuum the entire cure time would make a difference. Yes a vacuum will remove air, but the pressure is what compresses the composite. If there is no pressure to coincide with the vacuum you can lift the layers with the air that is trying to escape, depending on the porosity of the laminate material. That is why a flexible vacuum bag works so well, at first the air is removed as the vacuum is applied and then as the vacuum increases and the bag is pulled tighter on the part you get the pressure of it compressing the composite layup which tightens the layers and further removes excess resin, usually resulting in a near perfect ratio every time.
why not just clamp it between to planks? I wrap the micarta in oven anti stick paper, and clamp it between 2 planks, and i don't get any foids. i seen other people use wooden molds they clamp it in. to make it same size rectangular every time.
symmetric thickness.... unless using a steel plate both side wood tends to bow and be thicker in the middle
@@DjGlenJon yeah i found this out the hard way. I ended up welding a steel jig and use a very thick steel pressure plate that cannot bow and get great results now.
Exactly!
same advice either a vacuum bag or under weight. either way you got to have an outside force to squeeze the material to remove air and excess resin then its a simple matter of adding more material for thicker results.
A good idea! .... you need to put on the vibration, then the air will come out.
if you can put your scales into a vacuum bag and suck out the air. the colapsing bag helps to add pressure you need a release cloth on top of your scales and an absorbent material to catch excess resin.
Hi, I have no experience whatsoever but I saw other people vacuum their resin before the molding. Then you could additionally put the molded part under pressure for curing. It's just a hunch... Great channel! Cheers!
Black beard. Now i get it 😆
No music no noise= good job.
So interesting project! May I ask you about your camera? What's is model and lens?
I would have thought as some others have said, some 'down force' would be needed. The pressure pot would eliminate the air bubbles if the bubbled had somewhere to go. With fabric and resin layers, some bubbles cant escape and end up being trapped. putting a block of wood (wrapped in shrink wrap) and either clamped down or weighted with a lead weight or brick (or something heavy) would help squeeze the aire out and press the layers together. Great educational video.
Great channel .
I have never done anything like this before but I was wondering if you put wax paper on top and squeezed it down it would help on the delamination ?
I have experienced the same thing where poly sets up too quickly to allow air to flow out easily.
That stuff could make a nice knife handle.
um salve do Brasil + like. interessante. então é assim que se faz. muito bom. parabéns.
I think that as you remove air pressure the boiling point reduces, the air expands in your piece, and the voids occur as a result.
What about physical pressure? Like, if you presses it under a hydraulic press?
I think a hydraulic press would be a little overkill in this case... but yeah physical pressure is a tried and true method for making handle composites ^.^
@@KageStelhman i have both a 6 ton press and pressure pot..... the pot is better with certain resins
Standard procedure carbon fibre bike frame production. Hot pressing is the way to go
Woukdnt the best pressure be physical pressure? Have you tried curing it in a hydraulic or even a basic screw press? You will have no voids and have consistent flat faces.
Interesting experiments.
Anyone else have no clue what he does but can't stop watching it
Can you try placeing the materials in a bag and then using vacuum to pull the resin through the material? I know this is a process used when making carbon fiber panels so it may work here as well. Also it may cut down on the amount of resin used.
Maybe try squeezing in a vice ( between 2 metal plates ) and leaving it there to set?
Vacuum bagging should offer both clamping pressure and excess air / resin removal. Looking forward to more videos!
gteat test! thanke you for sharing
What if you combine mechanical pressure like a steel block and air pressure? Can you try it in a video?
Interesting video. I'm a bricolage fan and I have made some parts for my motorcycle, using epoxy and cabon fiber/vtr. Epoxy costs x5, but results are at least x10...flexible, tough, and good looking. And, obviously, gives you a lot more time for working.
An idea to reduce bubbles: you could try to do your work in 3 o 4 batches, then glue them together using the same resin. So you could work with "fresher" and more fluid resin. Pressing the layers together with some weight could also help. Slower, but - i hope - better.
Ps I'm italian too, but let's think to the global audience...btw, good english! ciao!
Your one of the best on UA-cam
Nice
Thanks great video. It would have been helpful if you marked one blank with a V and the other with a P.
Video has been nicely done
& quite informative.
Try this & let us know if helps...
Cut a metal block same size as the laminate blocks in this video.
(After sides cut off)
Cut, laminate, & place strips same as in video.
Place a single layer of 1/8" washers
(Honeycomb fashion on top)
Place metal block on top of washers.
Now put the prepped molding into the vacuum chamber.
I believe that you will like the results.
In a vacuum bag sounds like a good suggestion.
I suppose you could use a bottle jack with resin piece sandwiched between a rigid container & lid lined with plastic so it doesn't become too badly glued shut.
Polyester resin has 1 disadvantage, short shelf life of unmixed resin.
Epoxy can last for years if stored correctly.
This cavitation takes a very long time to go away and your essentially pulling gasses out of the liquid. Not necessarily air bubbles.
There is a method used with hydraulic brakes on bikes that use the cavitation to remove air from the DOT fluid and it's super slow. I usually just wait for the large bubbles to be removed and leave the microbubbles alone since I have never seen them fully disappear.
My suggestion would be to make a couple of forms that can stand up to the fly press you restored. make the forms such that you can use the press to apply significantly higher pressure on the composite material. this should reduce or eliminate the voids.
Nice video, and good of you trying to experiment and get to the bottom of this. My 2 cents: First, I think one should use employ both vacuum and pressure. Degas a pot slow cure epoxy (as you mentioned) in the vacuum pot and then place the soaked blank in the pressure pot. Secondly, I think fabric laminations (or any kind of lamination for that matter) should be held under clamp pressure while curing, regardless of the presence of air pressure or not.
I'm wondering if vacuum is making boil the solvent instead taking out trapped gas
I know and practice more comfortable way of doing it without vacuum and heating up, only pressure and some days of waiting, its much more better result as showed in video
Try squeezing the wet layup in a vice between thick wood blocks (use plastic wrap to prevent sticking). The pressure you can apply with a vice on that area is far greater and it would also compress the fibers together.
Another method for wetting out fibers is called "vacuum infusion" where you pull a vacuum in a sealed bag and use that same vacuum to draw out resin into your fibers. It's much quicker and yeilds far superior results.
Still, for micarta I would use the vice method.
Try rolling it after adding each layer, before putting it in either chamber. You can buy a small metal roller designed for laying up fibreglass. Maybe use slightly less catalyst to slow down the time before it gels.
what p.s.i do you use the pressure pot at? cheers great results
What if you take a piece of wood and make it taller then the mold you are using. Then take a heavy weight and place on top prior to pressurizing the canisters?
No suggestions. But you have extremely interesting videos. 👍🏼👍🏼
For flat surface, pressure is great and for any kind of shapes, trenches, vaccum is great.....if I am not wrong
You may get better results by setting the layers together in the open, so you can press out the air bubbles, before you put them into the mold. Then subject the molds to either pressure or vacuum. By eliminating the most bubbles possible in the open you should have better contact and adherence in the molds no matter if you use pressure or vacuum.
I apologize if this is in appropriate. Are stabalized wood scales safe to use on kitchen knives? Or is Natural Wood and Micarta the only safe material safe enough to be around food?
Thank you.
Hey dude, have you ever tried a press or heavy object? Isostatic pressure in a pressure cooker is not too high and vacuum degasses the resin. You need too vacuum and then press with much higher pressure (using a non sticky pressure transfer media e.g. a polyethylene sheet or do).
Nice. You used resin polyester and what is the second chemical in small bottle?
Great video....
Try vacuum bagging and pressurizing like they do with composite fibers.
Vacuum bag it !!! Garenteed to get all the air out !! I do it all the time.
Спасибо
mechanical pressure while in a vacuum will give the best results...like how G10 is made. squash the wetted fibre between two mould released surfaces to remove excess resin then vacuum to remove trapped gases.
Now please tell me the application of that????
Muito bom gostei um super like 🇧🇷✌️
I like it
Would like to have seen this done with Vinyl Est.
Very cool though. Your close man, like they say I think some physical pressure would help. If it's in a bag that technically puts pressure around/SA. Can't wait to see this on one of your blades. Stuff like Micarta shouldn't be TM, just IMO
First of all I would do some testing, if less hardener would result in a longer curing time. Also cooling down the resin before mixing should slow the hardening. Maybe cooling the cloth is also possible. Which would leave you more time for handling. Chemical reactions are very temperature dependent. After placing the layers in the mold I would simply weigh them down before applying vacuum or pressure.
How much proportion of rezin need to add
Have you tried hydraulic press? Good content as always thanks for sharing your videos :)
Eso para que se utiliza?
I make composite blanks all the time. You need mechanical pressure and then you will have no voids at all! 👍🏼
next time try a pair of clamps over boards on both sides.... way easier and better results