Hi Everyone, I just finished my second LFC with the suggestions from the folks here. Dawn dish washing soap, better aluminum, tilted pattern, a little salt for degas, etc. It turned out really nice. I am so jazzed with my new hobby. For the aluminum I used the cast aluminum housing pieces that I got from my Tesla models S motor after cutting the gearbox apart to free the motor and inverter to make separate units. The aluminum melted and poured beautifully. I did use a little salt to degas but not much happened that I could see. Here's some pictures. Now I'm looking at 3d printers to see if there is a way to make foam prints using some type of magic foam with the same properties of the foam used in lost casting. Anyway just a thought.
Well done, congrats! BTW, if you haven't already done so, read this thread: http://forums.thehomefoundry.org/in...ssions-of-a-lost-foam-caster-5-years-on.1650/
Hey, nice work Jack. Congrats ......and so the obsession begins That would be great but I'm not aware of any such material. Various lost _____ materials and allegedly printable waxes exist but PLA seems to be among the best printable pattern material, but it requires investment and burn out. And apparently not all PLA filament is created equal in this respect. Best, Kelly
I did read the confessions page and it was quite a good read. The Inswool is what I'm looking for now and found a place pretty local, I'll call them Monday. I've been making almost the exact sprue out of plaster of paris but I destroy one every cast. I already have the plug/buck/pattern for it. Here's a pic. I also found some new 3D printing LW-PLA filament that you can print at different heats to make it foamy. I've contacted the company and they are already trying to do lost foam casting without melting it out first. They say it's working but not perfected yet. It looks like it may be closer to pipe insulation foam type but without it being in my hands I don't know. Here's a link to their website. May be promising in the future. https://www.3dprintingmedia.network/colorfabb-foaming-lw-pla-3d-printing-filament/
If you want to make a pouring cup you can mold the ceramic fiber mastic (moldable ceramic fiber) around the plug like I did but you can also buy 1/2 thick 2300F ceramic fiber board and glue it together with the mastic. Ceramic fiber board is essentially the same stuff and is non-wetting by molten aluminum. You can buy a caulking tube of mastic on Amazon for $7-$15. Just make your cup with draft and make a sheet metal lifting cradle. The stuff is too fragile to handle with pliers, thus the sheet metal cradle. If you look at a couple of my casting videos you can see me emptying the cup immediately after the pour. If you lift slowly the metal fills the void more or less but that's why the pouring cups on my gated castings look ugly. Then pull the remaining foil afterbirth out of the cup with needle nose pliers and reuse it. You can patch any damage after multiple uses with the mastic. If you get carbon deposits, heating it will restore the surface to pristine condition. Best, Kelly
I've got a couple of rolls of the LW-PLA. When I was attempting my extruder mount castings, I printed a couple in LW-PLA. While much lighter than regular PLA, they density is still higher than EPS foam. Surface texture was good once it's dialed in.
There weren't as many on Amazon as last time I looked but I did find a couple. See below. I don't know how long the links will be good but key words should endure. Amazon.com: RC Pumpable 23-10 FL Oz - 2300°F Ceramic Fiber Caulk - Kiln Repair, Gap Filler,: Arts, Crafts & Sewing Here's another but ridiculously priced at $60. Fiberfrax Caulking: Amazon.com: Industrial & Scientific Here's a couple on eBay- make sure you watch shipping. One has ridiculous shipping. High Temp Ceramic Fiber Pumpable Kiln Repair Caulk 10 FL OZ Uses STD Size Gun 688945553272 | eBay CERAMIC FIBRE, PUMPABLE PASTE | eBay It can be harder to identify, and not a real common material but it's out there. I think you can do as well or better searching and buying directly from online or your favorite suppliers. Here's a couple key words for searches. ceramic fiber caulk - if you want a tube of it this is best key word. pumpable ceramic fiber moldable ceramic fiber ceramic fiber or refractory mastic seems more common.In Australia and Europe Be advised this product is available in both a "Moldable" and Pumpable version. Moldable is a soft putty like consistency and pumpable is about like cake frosting or pudding. Many manufactures brands such as Inswool, Kawool, Fiberfrax, etc. It's pretty much all the same stuff. If you search "pumpable ceramic fiber" or "moldable ceramic fiber" you'll find online sources. Typically carried by Kiln repair, and Foundry/Refractory Supply businesses. Searching the Brand Names may also help the search. Here's a gallon kit that can be bought on line $86. https://www.theceramicshop.com/product/1197/inswool-moldable-1-gallon/ ....and a tube of the pumpable. https://www.theceramicshop.com/product/1092/inswool-pumpable-10-oz-caulk/ Tube, 1 gal, 5gal, here: Ceramic Fiberboard Moldable Mix | 2300℉ | In Stock - CeraMaterials I get lot's of hits when I search but you have to plod through them. Prices vary widely. Fair rates would be 10oz tube should be $12-$17. $80/gal. 300-$350/5gal. Best, Kelly
That's Kelly, using your search tips, I was able to find someone fairly local that sells Morgan Kaowool moldable, $23.70Cdn/11 oz. tube or Fiberfrax LDS moldable ceramic fibre $20 for a 500gr container.
It's known by many different names and the nomenclature is very consistent, but if it's in a tube, it's most likely what I was calling the "pumpable" consistency. Some of the more interesting and useful properties of the stuff: Non wetted by aluminum and most non-ferrous metals. Any splatters or spills just peel right off. You can fire it at full heat immediately. This is useful if sealing a crack or making a gasket, but you may need to air dry or use modest heat for a shape molded on a plug depending upon your plug material. You will see some shrinkage. If it cracks or gets damaged, you can dig out, patch the area in minutes and it will be like new. It's about the most resistant material to thermal shock you'll find. The entire interior of my resistive electric furnace is made from the stuff. It's weird looking at this pristine white furnace interior.......but I like it. It is often used for transfer troughs and ladle liners, a somewhat pliable gasket material for same and for crack sealing. Sorry for the diversion jack.....back over to you. Best, Kelly
I'm curious as to why a person cannot use the refractory cement and cut up kaowool small pieces and mix them in and make sprues that way? Seems they would last a long time but again I'm a newby so I'm not sure of the drawback unless its the shock of the pour or ?. Seems ceramic board and pumpable seem to be about the same price as a bucket of inswol. Any thoughts of which is preferred?
Some refractories are rated for metal contact and could potentially work if it had a smooth finish and released well, but yes, it may craze and crack a bit from shock. The big difference would be the difference in thermal mass of the cup. The ceramic fiber is a great insulator it really preserves the pour temp of your melt. The metal retained is usually just a thick foil you can peel down and extract. Dunno about how well that would work with refractory, but I'm guessing it'd be a thicker skin. A bucket if "Inswool" could be pumpable or moldable, but yes, you are probably right, there may not be much difference in price per unit volume of material compared with board. It's really just a matter of what lends itself better to what you want to do. If you have simple geometry easily fashioned from plank, board will do. If you have a complex shape that needs a mold or plug to be formed, then moldable or pumpable may be better suited. Best, Kelly
Kelly, As always thank you for sharing your knowledge. I was really on the fence about starting to do my own castings and even contacted a foundry near me to do my pours and they where happy to do it but I was afraid they where not familiar with the keep on pouring after the foam initially starts to melt. So instead of worrying about it I decided to build my own setup. Your videos where so precise and you had such clean pours and cast parts I decided to do it. I followed your recipe except for using drywall mud instead of the expensive commercial slurry and plaster of paris sprues and it's working out great. I'm going to fix the Sprues but the drywall mud is going to stay as I can't justify the cost when these parts are going out great.
I'm glad they were helpful. That's very sensible. For aluminum it will produce very similar if not equivalent results. If you only do a casting or two at a time, and they have easy to access surface features, brushing makes sense. If the need arises you can dip with drywall mud too but then you have to have a vat big enough to accommodate and that takes up space and requires some mixing anyway if it's sits for long. My methods are just what work for me. There are many ways. Some I've evolved myself but many I borrowed or are just practical adaptations of commercial processes I've observed, but hey, that's the fun of it. Best, Kelly
