Moulding Sand Reprocessing
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- Опубліковано 11 жов 2024
- Reprocessing my moulding sand at the end of a days casting.
This is done while the sand is hot from casting - old timers believe that adding the water while the sand is still hot "steams" the sand and this helps reinvigorate the clay. I think they are probably right.
A real pleasure to see someone who actually knows foundrywork as opposed to some of the "foundrymen" Y T who think they do, your a great learning resource Martin thanks.
Headstock, I suspect that in some parts of YT "them's fighting words!" But you will get no argument from me! Thank you for the comment... Martin
I think this is the first video I've seen of what to do with the sand after the job is done. Love your channel, keep up the good work!
Nathan, Thank you for your comment. I guess that what people do with their sand at the end of each casting session depends a lot on what equipment they have. I don't have a muller so that option is out for me. I know that many other foundry men do use a muller, Luckygen for example often breaks his moulds out straight into his muller. This saves a lot of handling. however even if I did have a muller I would still use the aerator after mulling as if fluffs the sand up so nicely (mullers mix sand well and spread the clay nicely over the sand grains but they do tend to compact the sand). Many people use nothing more than a rake and shovel, the back of the shovel can be used to flatten and smooth out the sand while general raking and shovelling about will do the required mixing, its a bit more labour intensive but it works well enough.... Martin
I wish that I was not half a world away from you, because even though I'm 65, I be honored to apprentice with you!
Walter, Yeah, that would be about right - a 65 year old apprenticed to a 76 year old 😊. I would be equally honored ... Martin
I love watching a craftsman at work. Everything looks simple until you try it yourself. Thanks for showing your work.
I do a lot of my casting in lost foam as I very rarely do multiples. Dale K
Dale, Thank you for your comment. The appearance of simplicity comes with practice. It is surprising how often I also make just the one but it often happens that the first is not as good as required and a second is necessary foundry work is like that, so I tend to prefer a reusable pattern if it is quick and a bit roughly made from craft wood. However I have recently began to look at lost foam, I am in the read, learn, and observe phase and it seems that many practioners do not get it quite as right as they might! :) Lost foam seems easy but it does have some unique problems and unfortunately it is known for generally lower quality castings even ignoring the surface finish, still at times its a useful enough technique to be worthy of adding to ones repertoire.... Martin
Good channel Olfoundryman :)
Alumi, I am glad that you like it, Thank you for your comment.... Martin
You are such a great teacher of casting, surprised you don't have a million subscribers . Keep up the good work.
David, Thank you for your kind words - I think that I should have a million subs too 😀 But sadly that's not the way of it - most people watch YT to be entertained and not so much to learn stuff so people like me who aim to teach, illustrate, and show helpful stuff tend to suffer while those who make little attempt to do this but just try to entertain do much better. Its a source of much frustration but it is what it is and it won't stop me... Martin
After sweeping up the mess the day still isn't done till you knock the cap off a coldy.
Loving the videos and the detail in your info.
Cheers Eric
Eric, 100% correct! Most foundry men are great elbow benders. However, sadly (perhaps), I gave up the "demon fizz" over 30 years ago, nowadays its a good cup of tea and a good lie down, true, honest it is... Martin
A couple of interesting observations of Martin's foundry workshop.
1. Check out the size of that vice on the workbench, what a monster!
2. Did anyone else take note of the shape of his shovel and how it was worn down from scraping across the concrete floor?
One advantage from the cold weather is that it makes working in the foundry a nicer place to be.
Mark, Long story with the vice will email you with it (when time permits!) The shovel does wear and I have had to grind those sharp points off its edge of on a couple of occasions, due for it again now as they are a bit dangerous like that. Yes, this time of the year is good for foundry, I stood next to the furnace feeding a die all day a few days ago when the max was a little over 10 deg C I was the only one warm! But the summers are a bitch! Martin
Ken, Thank you for your comment. I assume that you are from Kentucky, we might be cousins! My male line spent time in Clay and Perry counties in the early 1800s, my ggf was born there , am tied up with the Couch, Eversole, Baker, Huff, Gay, and West (me) lines. All those moulding flasks, yes, something of a necessity if one has to make many castings each day as I often do. I made a gravity die to cast the flask sides, machined them on a friend's horizontal mill, and fitted Thompson 60 case 1/2 inch shafting as the dowel pins. The die was made so it could be quickly altered to cast different length sides. With it I was able to cast 200 sides in three different lengths in a day or two. I have been most grateful for these flasks, they have served me well!....Martin
Some of my coldest days were in the moulding dept of a foundry.
You amaze me with the knowledge your willing to share. When I first got into the trade I loved most I was taught by a man you remind me of, someone that had the knowledge and was more than happy to share it. I worked in a foundry for a period of time as a furnace helper, lost 40 lbs in 2 weeks, saw a lot of things like concrete burn, and water explode. Our furnace typically had a heat of around seven 28,000 lb pours a night. Pattern Dept was right next to us but never saw how they did things. You are filling in the gaps I always wondered about. Thank you!
Donnie, 40 lbs in two weeks yep, sounds about right and sort of reminds me of my two weeks carting hay in an Australian summer heat wave many years ago I did not have 40 excess to loose but I lost what I did have! Those are big pours. If I am managing to fil in gaps for you then I am well pleased... Martin
Fantastic. What a professional. A real pleasure to watch. Cheers.
Martin, thanks again for the very interesting video, the machine does a great job with the sand.
Thomas, Glad you liked it and yes, the machine really does do a nice job the sand almost feels silky afterwards. Martin
nice work...like and greetins from Brazil
Thank you... Martin
Hi Martin, simple y efectiva máquina...y después de 30 años no me atrevería a decir que necesita modificarse!!! jajajaa excelente...un abrazo!
Daniel, Thank you for your comment, yes, 30 years and still going strong. Martin.
Love this channel!
Michael, That's what I like to hear 😀… Martin
Thanks for this video Martin. Best regards from Mich
Mich, You are welcome, doing these videos is my pleasure, Martin
Another great vid thanks Martin!
JB, No worries mate! glad you liked it. When are you coming over? Martin
Got some stuff I'm working on for Melbourne office, not sure how it might tie in with a social visit just yet, hopefully not too far off though!
JB, I look forward to it, Martin
What issues could cause porosity in a pressurized die casting? In an aluminum part of course. I'm curious because you're the most knowledgeable person I have watched over the years.
Clarence, Sorry for delay have been in hospital for last 24 days. Pressure diecasting is not a process I think much of - I know its used to make lots of stuff in lots of alloys but personally I regard it as liquid metal forging rather than as a true casting process - just my bias of course.😊 The problem with the process is the extreme metal velocities that occur when the die is filled. The metal jets into the die and splashes everywhere, this is a recipe for much air entrainment and pressure die castings are know for often having quite large bubbles trapped in them. The very rapid solidification gives no time for any detrainment of these bubbles and they become locked in to the casting, the air pressure inside them can be quite high. Note that said porosity is not going to be due to hydrogen gas as solidification is so rapid that any hydrogen does not have time to come out of solution and form discrete bubbles. It is also unlikely to be true shrinkage as the pressure applied will prevent shrinkage from opening up. Its why you can not heat treat pressure die cast aluminium parts - the air bubbles cause blisters in the casting while it is very weak at the heat treatment temperature. It is not uncommon to use "overflows" around the casting proper, the idea being that the bad air containing metal ends up in these overflows and not so much in the casting - the use and positioning of these overflows requires care.
Thank you for the question - I do like a question with some "meat" in it......Martin
@@olfoundryman8418 thank you that is very informative! I hope you are well and I appreciate your response.
Just came back to rewatch some videos and learn something I may have missed last time I watched. It's been a while since you have uploaded any new videos so I hope you are doing well.
Brandon, Thanks for the repeat views. Am doing Ok just a bit busy, had some biggish casting runs and am currently making another lot of fine facing sand, a dirty dusty thankless job that I hate doing. As the years increase I am going slower and videos take ever so long to edit but I have two part done and maybe in a week or so I will have then up. The necessity of a new computer and new editing software has not helped!
Love watching your videos, very educational. I have watched lots of youtube videos and found that yours are by far the best. I do have a couple of questions.
Where do you aluminum and do you make the molds you use for casting?
Dale, Thank you for your comment, It is my intention to pass on the knowledge and experience that I have gained over many years so I am glad that you have found the videos educational. Your first question seems incomplete, are there some words missing? Yes I do make all the moulds both the sand ones and the cast iron ones for gravity die work. The latter are mainly turned on my lathe with some work on my old milling machine, a few years ago I purchased an (older) CNC mill and now use this for making dies too...Martin
Sorry about the incomplete question. Do you add alloys to the aluminum that you use in your casting.
Dale, No problem. The answer is "yes and no". I buy certified ingot for all my aluminium work. I can justify this expense ($3 to $4 per Kg) because I sell my work and indeed I have to do this as my customers want to know that I am using good metal and not junk like melted down cans etc. ..(Ugh!) Mainly I use what we call 601, its called 356 in the US and LM25 in the UK. This is a very common alloy and is the one used for wheels. Occasionally I use a 10 to 12% silicon alloy that we call 401, a piston alloy we call 319 but different from US 319, and a zinc/magnesium aluminium alloy we call A1E. Making up ones own alloys is a specialized job and really needs an analytical facility to ensure success otherwise its worse than pot luck as to what you will get. I note than some people speak of adding silicon to their aluminium and this is an almost impossible task as the silicon will not "wet and dissolve" and just floats on top. You just about have to melt the silicon to get it to work and silicon melts at a little over 1400 deg C, a bit beyond most backyard furnaces! Some people add copper but this creates an alloy that may corrode badly. The problem is that one never knows what "recovery" one is going to get i.e. how much of the addition is actually going to end up in the alloy, it is never 100%. Magnesium added to aluminium for example you get about a 50 % recovery, sometimes. However there is one alloying addition that I do make with a lot of my sand casting work this is an alloy called "5/1 tibor" it contains 5% titanium and 1% boron. It is a grain refiner I add it at about the rate of one part in 1000.... Martin
I've watched all your videos. I'm already itching for more. Love your stuff sometimes it is hard to here you. I sarted using a wireless microphone in my video. And that helped a lot. By all means have a view I do a bit of pattern making am machine tool restoration. I'm trying to set up a line shafts machine shop. Any way I'm sure you would have good advice for me. Next thing I do with patterns I'll link to you and see if I can send you some more viewer. Chris a:)
Chris, Thank you for all the views and comments, I really do appreciate them. Yes, I am aware of the sound problem and indeed I do have a wireless mic set up in mind Boya WM 6 is looking likely but its nearly $300.00 (out here) and I am also considering a better editing program and that is another $300.00 Not too sure I want to put in all that money at this stage, perhaps the mic first! I use a Gopro and they have the annoying habit of turning the sound volume down after any loud noise so my voice just fades away for a second or so after I drop a tool on the bench for example, there does not seem to be a way of turning this most frustrating of features off. I think it is the worst feature of the Gopro but some other cameras do it too, why, in heaven's name why!
Line shafting eh, fast and loose pulleys and lots of people caught in long flapping belts, ah, those were the days! :)
I have a private message to you in mind when time is a bit more available, I watched one of your videos and I have a few (constructive) comments to make. Till Then....Martin
PS I regularly use a mill right up your alley a Cincinnati No2 vertical very old, very worn, and very tired, I fondly call her "The Beast."
Olfoundryman I never have had this problem with the sound on my go pro what mode do you have? I've b r n using the removu m1 + a1 Bluetooth mic set it runs for less than $100 u.s. . I was lucky enough to get the cone pull for my 16" southbend but I need to come up with the double clutch assembly. If I can just find one to copy I'll be in
Chris, I use a GoPro hero 4 silver. Always in a case because of the dust but with a Rode external mic. I had a look at the Removu unit and I was impressed, for the money it really is very good. In fact it is on special out here now for about $50.00 a real bargain and I would have already bought one except that it is a backpack unit and that would obscure the rear screen. I use the screen to frame my video and I don't think that I could get use to not being able to use it
Olfoundryman if you have a smart phone you can use there app. To view and it will work as a remote control as a bonus.
Hi Martin, There seems to be a lot of confusion about lost foam and some of the techniques do not impress me. I have a CNC mill/router and a pantograph hot wire profile cutter that I use to fabricate my patterns. I glue them up with hot glue gun or tape. I have coated some of my patterns with PVA glue or bon-Crete to improve the surface finish but Metho with powered graphite gives a clean casting. The sand I use is a mixture of about 4% sodium silicate. I vent these patterns but I usually burn out the foam before the metal is cast. I have made a Muller but now I'm going to build the sand conditioner that you have shown us.
I'm on my computer which is down the shed as the computer inside is in high demand. Dale K
Dale, Yes, indeed confusion reigns supreme. Many people who attempt it seem to have little real idea of what should really happen or how to achieve that. People are even covering their foam with thick layers of plaster of Paris or even metallic tape,,,, the mind fair boggles! I assume that you are using a silicate CO2 sand, Yes? Originally of course they just used green sand. And then the variant of using a coated foam and dry loose sand to take full advantages of the process was developed. A friend (a pattern maker) has made quite a few lost foam castings a recent one was a bell housing gearbox adaptor, it was quite large made from several pieces glued together with masking tape covering the joints it was moulded in a fenotec hard sand and it worked well. Vegoilguy and I have been cooperating on trying the dry sand version of the process where the pattern is coated with a thin porous ceramic layer. At this stage we are just experimenting with the coating formulation, it has to be thin strong and most importantly porous. Our first effort produced a beautiful coat except that it was non porous! So all the gas coming from the decomposing foam came out through the metal, not good. I have developed a few porous coats but have not yet got around to trying them out properly (Oh so many things to do and so little time!) Your version sounds more like investment casting if you are doing a pre cast burn out what temp do you go to with this burn out how does the silicate sand handle it.
I think that you will be well pleased with the sand conditioner - I was! Please let me know how it all goes... Martin
I like to watch skilled men improvise things through ones only dream about.
Dave, Its just a matter of practice... Martin
Hola buen día .quiero agradecerle por ser tan didáctico.sigo su canal y mi trabajo a mejorado muchísimo de hecho logré una salida laboral gracias a la calidad lograda.gracias
Jaun, If my forthrightness has helped improve your work then I am well pleased.... Martin
How's your back after all that bending? Ouch : )
Geoff, Yep, that bending is a problem. Hence my thoughts about a pneumatic conveyer based on the coanda effect to move the sand while I sit on a chair :). My physiotherapist is amazed that I can do it as my back is a total mess (had a disc removed nearly 50 years ago) But he says that I probably can do it because I do do it and bad as it looks it only takes 5 minutes for 200 litres of sand. But it sure is my least favourite part of the job!.... Martin
Qhat refractory is your furnace lined with? Looks like it has layers. I am Currently building one I have a big box of kaowool. The castibles seems too heavy. But not sure what to use for hot face? I was hoping that you may have a do it yourself type of hot face. :)
Thanks
K, My furnace is lined with a castable refractory called "Thermocast 165" it is rated to 1650 deg. C. It is about 100 mm thick and is surrounded by about 100 to 150 mm of loose vermiculite as insulation. The lining was made in about 1972 and is still going strong despite having done thousands of melts. It is heavy and takes a fair bit of heating up but it has lasted very well. Kaowool will not last anywhere near that long even with a hot face. First you need to check that your Kaowool is rated for a high enough temperature as it is available in several grades and some of them will not go that hot. Considering the cost of the Kaowool (its not cheap!) and that the furnace is your most important tool I would simply buy a decent hot face material of the trowel on type from your Kaowool supplier. I do not know of a home brew hot face. I think Luckygen1001 did a video on a reline of his iron melting furnace which is I think kaowool based, if you can find that video perhaps it can be of assistance. (I have not seen it so I don't know for sure)... Martin
Use oil sand in my ratty old setup in London, but that processor is going to be the inspiration for something built here......
Old, I assume you mean that you use petrobond sand. To be honest I do o not recommend that people go to the lengths I did to produce a very fine facing sand there are just too many issues with doing this and it does cause problems that require extra effort to overcome. Considering that a good petrobond sand will produce a finish almost as good as my fine facing sand my6advice is stick with the petrobond but do make a point of using the best running and gating methods - they help with finish too... Martin
One of the best bits of kit that I have is just an air chisel fitted with a flat steel foot , which rams the petrobond down pretty much brick - hard in short order. Also using McEnglevan / MIFCO aluminium moulding boxes, which are truly excellent .@@olfoundryman8418
Yes I use CO2 and I have holes around the molding boxes to help gas the sand. I have as yet to find a way to use dry sand without collapse. I use oxy acetylene with a cutting torch so that you can use excess oxy to get rid of the foam. The sand is tolerant to the heat and when the smoke clears it is ready for the metal. Not all of the foam is burnt but the residue has little effect on the casting. I'm in Tassie where are you. Dale K
Dale, Tassie eh, ah well just wait for the next ice age and we can walk to each other I am in Melbourne. Have relatives in Hobart. I do a little silicate CO2 core work (much prefer shell) so am familiar with the process, if you are having trouble with breakdown of the sand after casting try adding 1/2 % glucose powder (available in health food shops) to the sand before you add the silicate, sand will hose away after casting. To stop the dry sand collapse you do need to coat the foam. Commercial coats are available from Foseco and Ask Chemicals but we are trying to develop our own. The coat has to be thin 0.5 mm or so, strong enough to withstand the vibration when the dry sand is compacted around the foam, refractory, and above all porous so the liquidized /gasified foam can get out through the coat, this porosity is the trick and is what we are working on.The dry sand should be coarse, way coarser than a good green sand. Another trick that should be done is to place a steel plate or similar on top of the dry sand the weight helps to lock the sand into place. Do you ever get to Melbourne?... Martin
I would love to see the dies for the mold flasks.
Scott. Its been many years since I used this die, I think its lying around somewhere, I think! Two possibilities contact me via a PM with an email address that I can send some photos to and I will dig the die out and take some useful pics of it for you. Or wait a few months till I can get around to it and I will set the die up properly in the little tilt caster it fits in and I can at least do a dry run or maybe even (if there is enough interest) and actual casting run with it. Or as a third choice I guess both of the above, photos for now, dry or maybe wet run video later. If you lived close enough you could come and spend a day casting 100 or so for yourself while I sit back in a deckchair with a cup of tea and bark orders :).... Martin
Olfoundryman iHi Martin, thank you for the response. I would love to take you up on your offer but I live on the other side of the world. I looked for a way to PM you but on the ABOUT tab of your channel there was no option to send you a message. I can wait for a video. There is no question that there is interest. Other users have complimented you on the flasks. You have the best foundry channel on youtube. Please keep up the great work. We all enjoy it and are learning a lot.
Scott. Just hop on a plane! Still 100 box sides might constitute overweight luggage on the way back!
Ok, I will dig out the die and see if it can be resurrected and possibly run for a few castings but don 't hold your breath it will take some time as I have a lot on and being old I am slow! A few months at a guess.
I went to my channel and under "about" there is a little square text balloon type thing, its just to the right of a small flag. If you click the balloon it turns out to be a message send thingie. I also got a friend to check on my channel on his computer and same thing so I guess it should be on yours if it isn't we will just have to put it down to one of those YT mysteries, there are a few! Try again to see if you can send me a message so I can at least send a few photos of the die to hold your interest until I can do a run of some sort. Yes the flasks are the best thing I have ever made, thousands upon thousands of castings have been made using them. Although if I was to make them again I would use a different design, one that is more versatile. I have been contemplating a video on my journey through moulding boxes over 50 plus years. Crap wood to cast aluminium all in various iterations as my needs, thoughts, and experience developed. My recommendations for box materials and design would be included and I have a particularly versatile design in mind that I think would suit most backyarders.... Martin
Hi Martin, I got sent here from Luckgen1001, I was hoping to get some castings made, is this something you would be interested in? Cheers Matt
Matt, Bless luckygen! I am always happy to look at anything that people want cast. I can't do large work though. I suggest that you PM me via "about, message" with an email address and we can start things off. I assume that you are local, Melbourne?... Martin
I'll be keeping an eye on you videos to see what transpires. Global warming is an ass. No bridge.
Its been global warming ever since the last ice age.