View Full Version : clay for aluminum casting

12-27-2001, 11:05 PM
Anyone know any good alternitives to fireclay for binding casting sand? This will be for relatively small aluminum castings for a tube notcher. I tried some red clay dirt dug from the ground, but it takes way too much water to get a good bind with it. My first cast burped itself right back out the sprue hole. I'll use fireclay if I can find it locally, but am looking for other (possibly cheaper?) alternatives. Thanks alot!!

12-28-2001, 12:06 AM
try www.budgetcastingsupply.com (http://www.budgetcastingsupply.com)

Gremlins in the edit...

[This message has been edited by Thrud (edited 12-28-2001).]

12-28-2001, 09:09 AM
Fireclay is cheap, it comes in a bag like Portland cement. It can be found at some lumberyards or where they sell concrete blocks, firebricks and such.

You might consider some boughten oil mixed sand, getting green sand just right takes a while. I poured a small casting this summer, took a couple 3 days of adding water and working sand to get it just right.

12-28-2001, 10:16 AM
I don't know exactly what you are trying do with the "fireclay" (I thought that it was used for making firebricks and crucibles), but it sounds like you are wanting to use it as a "green sand" substiute. If that is true, I can't help you. However, if you are trying to find "green sand", when I went looking for some, I contacted a local foundry and talked to the owner. After explaining that I wanted to do some "hobby casting", he gave me 3 five gallon buckets of the stuff at no charge. They used tons of it for their operation and said that he wouldn't even miss it.

12-28-2001, 11:33 AM
Thanks for the replys. I guess I'll keep looking for the fireclay. bugetcasting.com has that premixed sand which sounds nice, but like I said I'm trying to do this on the cheap. I have looked for a local foundry, but had no luck. Will try calling around Nashville soon to try and find one. In the meantime I'll keep messing with the red clay for lack of anything better to do. Thanks again!

12-28-2001, 01:27 PM
bentonite clay can be used but you use a lot less . This should be easy to find if you are in farm country , I used some pottery clay that had a high fire clay content, I used a higher ratio of clay than normal and it seems to work great.The big problem with the pottery clay was that it comes moist which made mixing it with sand a real pain. The problem with the bentonite is that is bad for the lungs so mix it outside and try to avoid inhaling the dust. some sort of dust mask when you are combining it with the sand would be good idea in my opinion. good luck.

12-28-2001, 09:27 PM
Did you put in enough vents? to let steam excape.

12-28-2001, 09:33 PM
I believe I had enough vents in it. The problem was just too much water in the mix. I'll look around for either fireclay or the bentonite tommorow. What is bentonite clay used for exactly? Thanks again

charlie coghill
12-28-2001, 10:10 PM
You might try a well drilling co. They use bentonite to seal around the top of the well casing.

12-31-2001, 11:58 PM
The compound they use for investment casting Jewellery will work with any metal safely up to Platinums melting point. It is a specially formulated ceramic that disintegrates in water after the casting has cooled. Get it at lapidary stores or check with www.budgetcastingsupply.com (http://www.budgetcastingsupply.com)


ralph mitchell
01-15-2002, 07:26 PM
I use bentonite for my castings. I havent done much casting because its a lot of work. What i have done has worked pretty well. I got my bentonite from a feed store. I guess it is used as a binder in rabbit food. I dont think it is very harmful.

01-16-2002, 06:51 PM
If you're in the Nashville TN area you can probably find bentonite clay at a Farmer's Co-Op outlet - those around Huntsville AL have it. In addition to a livestock feed binder it's used for lining farm pond bottoms. (The local Co-Op was happy to give me several partial/broken bags just to get the mess cleaned up!)

[This message has been edited by lynnl (edited 01-16-2002).]

[This message has been edited by lynnl (edited 01-16-2002).]