Metal Casting Zone

vanekkm wrote:
Here's a Formula for Green Sand I found on the internet:

"Green sand formula
100 lb Dry sand (80-100 grit for casting iron, 100-120 grit for casting aluminum, brass and bronze - I used 125 grit)
10lb bentonite clay (preferably Southern bentonite - I used a combination of Southern and Western).
15lb fireclay.
3.5 to 4.5 litres water.
3 lb Fine sea coal (very fine coal dust). This is only needed when casting cast iron to give a better finish, it does nothing for aluminum castings but doesn't cause any problems either, I didn't use this as my sand is likely too fine for cast iron work anyway." www3.telus.net/public/aschoepp/sand.html

Give it a whirl and let me know how it works or what your favorite Green Sand Forumla is.

Looks interesting, did anyone give it a try?

Hello there,
that is interesting page but in a shop where they sells garden supplies they usually also sells bentonite only much cheaper.

Kind regards,
Stirling

Thanks sterling for thr update

Any garden supply sites?? Thanks,Penso

If anyones interested EBay has bentonite on sale from a Texas Ceramics site.

Some people can find clay in their backyard or in a creek that will work.
You just need to play around with it and see if it will stick the sand together.

Well drillers use bentonite clay and it is put in the bottom of ponds so they don't leak.

The clay is not to stand up to heat, only to stick the sand together.

HHWC3 wrote:
Some people can find clay in their backyard or in a creek that will work.
You just need to play around with it and see if it will stick the sand together.

Well drillers use bentonite clay and it is put in the bottom of ponds so they don't leak.

The clay is not to stand up to heat, only to stick the sand together.I have a really gummy,sticky grey clay on my 40 acres. I'm not sure of the heat factor of it. It sticks to everything so I suppose that I could mix a sand in it. I was going to make bricks out of it but a neighbor said that it wouldn't work. Come Spring I'll experiment with it.

If you have grey clay in your back yard then it is probably bentonite, In my back yard there is 2 layers of bentonite one at 24" and one at 36" deep, each layer is about 6" thick. I have dug this clay and let it dry for about a week in the sun, then pulverised it, sifted it thru a 250 micron screen, and then mixed with sand, then added water. It was a bit of work just to save a few bucks but what the heck it worked.
I live on the east coast USA. If you live on the west coast you may have montimorilite clay, Im not sure how well it would work as a binder as it is formed from volcanic ash. might work as fire clay though.....

You find a green sand formula in the book "pirotechnia" from Vanoccio Biringuccio. First edition from about 1570. There is taken one part fine river gravel or tuff, a third part young rams ashes and a twelft part of the whole of old flour. To moisten it he says you should take wine or urine. I drank the wine and took the urine
Instead of the rams ashes I took normal hardwood ashes. It worked but nothing for the normal.

Greetz Blaubär