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Metal Casting

Posted: Sat Jun 02, 2007 10:10 pm
by Modderxtrordanare
I'm getting really interested in metal casting, but I don't know where to start.

I plan on starting out casting something simple, a metal (aluminum) ball. Eventually working my way up casting things.


I can't quite understand how to build a foundry. I've drawn up my basic idea on how it works, odds are it's wrong.

Image

Thats what I would use to melt the metal down. Now to cast it I would probably sand cast it, because I don't know how to make a permanent mold.

Posted: Sat Jun 02, 2007 11:03 pm
by A-98

Posted: Sat Jun 02, 2007 11:58 pm
by Modderxtrordanare
So I don't need to use a refactory of some sort?

I've seen that link, and that foundry looks different than the ones on backyardmetalcasting.com

Plus, it doesn't show me how to cast in sand. How would I go about making a permanent mold that I don't have to keep making out of sand every time? I want something I can just pour the metal into and when it cools open it up and have the cast.


Edit: How do I cast with wax and would the molds I'd make out of wax be reusable (even for only a few more times), or would I have to make it out of metal or something?

Posted: Sun Jun 03, 2007 1:41 am
by singularity
<a href="http://www.instructables.com/id/EC1S0WG ... STEPS">yet another ghetto furnace</a>

edit - sorry about that i hit ctrl+c instead of v

Posted: Sun Jun 03, 2007 2:15 am
by Modderxtrordanare
Your link just goes to spudfiles' forum index..?

Posted: Sun Jun 03, 2007 3:07 am
by Kronnkk
ok, ill try to help make a pattern out of wax and make shure you have a sprue ,or vent at the top of all outer leggs ect
then mix up plaster of parris and pour up to the halfway mark on your wax let the plaster dry over night and drill two or three cone shaped indents in the plaster 1/2 inch away at least from the wax give whole mold a good spray of pam cooking spray and fill whith more plaster let dry overnight
next day turn mold over on a cookie sheet {not your wifes favorite one,lol}to save your wax and heat untill the wax runs out remove the wax cookie sheet and slowly heat up to melting temp of your casting metal {you heat slowly to make shure there is NO water pockets in the plaster,if ther are the mold will crack,been there} slowly turn over and pour yor molten metal in the negative space that the wax was in ,sorry my typing sucks

Posted: Sun Jun 03, 2007 3:16 am
by Modderxtrordanare
I'm confused by your instructions, could you possibly clarify or give more detail on what you mean by all that?

Posted: Sun Jun 03, 2007 5:08 am
by jrrdw
How well will plaster hold up to moltent steel? Wont it pop and crack then crumble causeing/letting the steel/aluminum run out all over the place? From what i was tought, the sand used in castings is from Egypt, the quiltys are such that the metal cools fairly quickly and the sand is housed in cast iron caseings, heavy duty ones. Making candles is one thing, pouring melted metal is another.

Posted: Sun Jun 03, 2007 7:34 am
by mark.f
OK, only one logical idea for getting you a good understanding of the basics of metalcasting.

Order David J. Gignery's book, The Charcoal Foundry. That will tell you about everything you'll need to know.

Posted: Sun Jun 03, 2007 10:17 am
by Fnord
Plaster wil stand up to molten aluminum just fine. If you want to cast steel you will need to preheat the mold to 1500 F or so(it will be glowing nicely).

If you want to cast steel you'll need a furnace, but aluminum can be melted with charcoal and a fan/hairdrier for an air supply.

Posted: Sun Jun 03, 2007 2:07 pm
by Modderxtrordanare
Aluminum is all I plan on melting, for now. Beginner stuff. I'll look into that book mark, do you have a link by any chance?


Edit: I still don't know how to make a permanent mold, be it plaster, another metal, or something else entirely.

Posted: Mon Jun 04, 2007 8:11 am
by Fnord
If by permanent you mean one you dont have to break to get the cast out, look in the how-to section. I made a cannonball tutorial there.

Posted: Mon Jun 04, 2007 9:07 am
by Spuddin
a perm mold could be a challenge for sure but u can always use foam for your pattern which requires a hot wire foam cutter that can be made with stuff u prolly have laying around.
www.freewebs.com/minifoundry
www.freewebs.com/spuddin