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View Full Version : wooden molds for casting aluminum ??



steve herman
01-02-2016, 12:32 AM
Needed some chuck stops for my small lathe, so I thought why not make them out of wood even if the just lasted one time and burned up.
to my surprise some of the molds 2 and 3 times. I could make one on the rotary table in just 12 minutes

Steve
http://i784.photobucket.com/albums/yy126/steveherman/013.jpg (http://s784.photobucket.com/user/steveherman/media/013.jpg.html)
http://i784.photobucket.com/albums/yy126/steveherman/007_1.jpg (http://s784.photobucket.com/user/steveherman/media/007_1.jpg.html)
http://i784.photobucket.com/albums/yy126/steveherman/016.jpg (http://s784.photobucket.com/user/steveherman/media/016.jpg.html)

steve herman
01-02-2016, 12:35 AM
http://i784.photobucket.com/albums/yy126/steveherman/017.jpg (http://s784.photobucket.com/user/steveherman/media/017.jpg.html)
http://i784.photobucket.com/albums/yy126/steveherman/018.jpg (http://s784.photobucket.com/user/steveherman/media/018.jpg.html)

danlb
01-02-2016, 01:15 AM
How close did they hold the dimensions?


Dan

boslab
01-02-2016, 01:19 AM
You could also try cement board, over here it's used for garage ceilings when the garage is in your house and for steel covering, I'm told it works, also drywall may work too,
Nice job
Mark

darryl
01-02-2016, 01:59 AM
There's also the lost foam casting method where you make the part in styrofoam then pack sand around it. Pour the molten metal directly into the foam and the foam disappears, leaving a pretty good cast part behind.

KiddZimaHater
01-02-2016, 02:26 AM
That's really a great idea.
Now just clean them up, and face 'em off.
Good job!

wierdscience
01-02-2016, 09:06 AM
Yup wood works,so does sand and sodium silicate also steel moulds,though with steel some draft needs to be included.

old mart
01-04-2016, 02:58 PM
Take the batteries out of the smoke detectors first.

Paul Alciatore
01-04-2016, 03:36 PM
Be careful. Some woods have a higher moisture content and it can instantly turn to steam when the hot metal hits it. You may have molten metal flying all over the place.

Years ago, when I was young (teenage) and stupid, I tried to do some aluminum casting using plaster of Paris for the molds. On the first try I had an instant volcano with liquid aluminum shooting up a couple of feet. Lucky me was off to the side, but it could have been much worse. I did find that baking the plaster molds in the oven for a half hour or more did remove the moisture.

garyhlucas
01-04-2016, 06:46 PM
Looks like if your wood was a bit thicker and you didn't fill it all the way you'd have a lot less cleanup work. I've been thinking about trying lost foam casting. Cnc machining a block of foam would go really quick and you don't have to concerned about undercuts and such. Don't have a furnace at the moment though.

gellfex
01-04-2016, 08:48 PM
Interesting. I was thinking about casting some sinkers from lead pipe I pulled out of a wall. Lead melts at half the temp of AL. What I'd really like to do is cast some molds for bucktails, but a friend told me plaster or gypsum cement would fail dramatically at that temp. So maybe carve a wooden bucktail and cast an AL form around it. Or a foam one I suppose.

Black_Moons
01-04-2016, 08:54 PM
Be careful. Some woods have a higher moisture content and it can instantly turn to steam when the hot metal hits it. You may have molten metal flying all over the place.

Years ago, when I was young (teenage) and stupid, I tried to do some aluminum casting using plaster of Paris for the molds. On the first try I had an instant volcano with liquid aluminum shooting up a couple of feet. Lucky me was off to the side, but it could have been much worse. I did find that baking the plaster molds in the oven for a half hour or more did remove the moisture.

I tried something similar, my problem was after baking plaster, it turned back into something with about the strength of plaster dust :P

mickeyf
01-04-2016, 10:28 PM
you make the part in styrofoam then pack sand around it. Pour the molten metal directly into the foam and the foam disappears

"disappears" == "converts into toxic vapour", illegal in some places and not too environmentally friendly in any case. If you must do this, at least be safe yourself.