green sand

[iron ant]

I am doing test for a new series,involving cast aluminum and steel/stainless.I use to use a resign bonded sand,but I wanted to maybe tdo green sand,I remember a long time ago someone saying you could mix sand,clay,and?.There is a third ingreient,anyone have any clue what it could be?I am pouring open molds,and would like to reuse the sand.....IA

[SPRINGFIELD]

Originally Posted by iron ant

I am doing test for a new series,involving cast aluminum and steel/stainless.I use to use a resign bonded sand,but I wanted to maybe tdo green sand,I remember a long time ago someone saying you could mix sand,clay,and?.There is a third ingreient,anyone have any clue what it could be?I am pouring open molds,and would like to reuse the sand.....IA

That third ingredient could be bentonite. I'm not sure if I spelled it right. I just bought and used some Green Sand Casting Base that I bought on E-Bay. You can add this to some sand at 10 lbs Green Sand Casting Base to 50 lbs sand. The sand I used was 90 mesh oklahoma sand. You mix the two togather and than just add some water till it feels right. Best stuff I ever used. I also read somewhere that to restore casting sand you just add a little more bentonite. I made a mold and poured an aluminum casting and only 1/16 of the sand right next to the casting changed color slightly. The change was so slight that I didn't even bother to seperate it out. I've used
petrobonded sand to cast aluminum and what a blackended smelly mess it left the sand in. This has opened up a whole new world of casing for me.
If you want to try out this guys stuff it's sold by
Frostic Incorporated
4191 Waug Road
Benzonia MI 49616 or just look for his product on E-Bay I think I found his product under Metal Casting. Hope this helps.

[sculptor]

Green sand is a mix of pulverized coal, water, bentonite clay and sand.

if memory serves, the sand used a long time ago was olivine instead of silica, but, i don't think this matters

start with 85% sand, 5% coal and 10% bentonite all finely ground to a flour like powder----vary as per your curiosities, tastes, or desires
add about 5% water---just enough so you can squeeze it into a ball that holds it's self together

the coal will burn off and out gas as you cast