Slurry for investment casting

[Rudy2]

Hi all,

I have been reading lots of stuff on the internet and have even made a few phone
calls to casting supply companies that cater to investment casting supplies for
industry.

What I am looking for is an affordable solution for an investment slurry and
reinforcement (white silica sand?) so that I can experiment with casting aluminum and
bronze at home. Some have suggested plaster of Paris, Portland cement, and
masonry mortar but I haven't found anyone who is willing to say what actually
works. I plan to cast wax patterns in rubber molds, invest them, do a high
temperature burn-out with a pottery kiln, and then cast while still hot.

Any of you folks have experience with this? Maybe shoot me in the right
direction for more info? Thanks.

Randy

[79TigerPilot]

I would give the Shidoni Foundry, just north of Santa Fe, NM a call. I was there once on a Saturday and got to seem them pour several hundred pounds of bronze, way cool!

Shidoni*-*Home Page

They use a lost wax process and coat the wax with investment material. As much as I can remember they dipped the wax in a liquid then dip the coated wax in a fluidized bed of investment silica material. When that was dry they would go back do it again and again to build up the thickness to the desired level. Then it went to a huge burnout oven to melt out the wax and harden the mold.

At the time they had open house on Saturday with a pour in the afternoon. You could walk around the shop, talk to the tecks and artists. Then stand 10' from several hundred pounds of bronze being poured into various projects. We were so close, if lade had broken our feet would have been in serious hurt.

If you find out the nature of the materials please post.

Craig

[beone]

I do only green sand but plaste of paris, portland cement and morter and silica sand are about as cheep as is possible. why not just get some and try it?

[awerby]

But casting high-temperature metals can be quite dangerous, especially if you don't really know what you're doing. I'd strongly urge you to find someone who does know how to do this, and get some hands-on instruction. There's a lot to this besides knowing what "slurry" to use, and small-seeming mistakes can be fatal, to you as well as your projects.

Hi all,

I have been reading lots of stuff on the internet and have even made a few phone
calls to casting supply companies that cater to investment casting supplies for
industry.

What I am looking for is an affordable solution for an investment slurry and
reinforcement (white silica sand?) so that I can experiment with casting aluminum and
bronze at home. Some have suggested plaster of Paris, Portland cement, and
masonry mortar but I haven't found anyone who is willing to say what actually
works.

[They probably don't want to have to feel responsible for what happens to you when you try this at home...]

I plan to cast wax patterns in rubber molds, invest them, do a high
temperature burn-out with a pottery kiln, and then cast while still hot.

[Except for the very most delicate patterns, it's not really necessary to cast while the molds are hot.]

Any of you folks have experience with this? Maybe shoot me in the right
direction for more info? Thanks.

Randy

[Where are you? Maybe there's an art college or foundry nearby where you can take a class.]

Andrew Werby
United Artworks- Sculpture, Jewelry, Furniture,and other Art Objects, plus Art Resources, Techniques of Sculpture, Jewelry and Lapidary, an Online Bookstore, and a Custom Art Referral Network

[Rocco85]

HERE's some good info on using plaster based products for metal casting.

[Geof]

Find a hobby shop that caters to people who do silversmithing for a hobby. Lost wax casting is used for jewelry making.

The slurry is a clay material which can be baked to harden it, almost like low temperature ceramic firing. But as Andrew says there is a bit more to it than dipping your wax pattern in a puddle of clay and cooking it in the oven. Follow his suggestion and find a night school course or a local club.

[RICHARD ZASTROW]

The French used to cast bronze bells using cow manure. I really don't recommend it though.LOL

Dick Z

[Geof]

Not straight; it was mixed with clay.

I think that is also the daub in wattle and daub as used for the walls of houses many eons ago.

[RICHARD ZASTROW]

Geof, That process must still be used today in castings for bull horns. The type the idiot protesters in Wisconsin are using spout nothing but bulls**t.LOL

Dick Z

[davidmb]

Try looking for a dental supplier in your area, gold crowns are cast using investment plaster, with a lost wax process.

[bozidar22]

i have used a mix of plaster of paris and fine white sand to cast aluminum. Straight plaster has a lot of moisture and will blow up.

add as little plaster to the sand. just enough to bind it together.

bake to drive off any water. I've also used a microwave oven.

my molds were split, so i don't know how it works with wax.

do some exsperimenting. just make sure there is no moisture in the mold.