Metal Casting Zone

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.

what does the fire clay do to the mix? I have made my own green sand by mixing
100 lbs sand to 10 lbs bentonite clay and 10 lbs water. This made a very sticky green sand that rammed up great and I had no problems casting aluminum at all. I am new to casting metal parts but my very first time casting (last weekend) useing nothing more than tree trimmings in a piece of 14" ss pipe sitting on top of a metal grate supported by bricks produced a nice bright shiny aluminum part. No blower either just natural draft.....

aonemarine wrote:
what does the fire clay do to the mix? I have made my own green sand by mixing
100 lbs sand to 10 lbs bentonite clay and 10 lbs water. This made a very sticky green sand that rammed up great and I had no problems casting aluminum at all. I am new to casting metal parts but my very first time casting (last weekend) useing nothing more than tree trimmings in a piece of 14" ss pipe sitting on top of a metal grate supported by bricks produced a nice bright shiny aluminum part. No blower either just natural draft.....good one its not rocket science like many state. my sand mix is similar to yours

You don't need fireclay it greensand, it is not as sticky as bentonite clay and you not going to fire anyway, so why use it.

Bentonite is on the high side of sticky but on the low side of temp range and a high temp clay is not as sticky.

I just saw an interesting commercial advertising MOON SAND!! Its a kids play sand that sticks together very well. Id did some researching and it is made useing corn starch and water. wonder if this would work for casting??

Hello everyone,
I am new in the sandcasting but I thought you had to use oil instead of water and that water was best to avoid because of steam formation, with disastrous consequences.
kind regards Stirling

oil sand is the classic,

but it can be messy.

we all seem to have the desire to find a cleaner,

easier way to make sand castings.

i have tried many alternatives and had good luck with most.

the water is not usually the problem.

irontwig

I hear about a very old time casting sand useing molassas as a binder, To my understanding it works very well but gets a very unpleasent odor after a few days.
I have never tried it myself but dont see any reason why it would not work.

I'll have to keep that in mind when I do my first cast. Maybe just make enough for the one cast.

aonemarine wrote:
I hear about a very old time casting sand useing molassas as a binder, To my understanding it works very well but gets a very unpleasent odor after a few days.
I have never tried it myself but dont see any reason why it would not work.

You use the molassas mix to make cores with.
Bake it in a oven till it is hard and put it into core prints in the mold so you can make a hollow in your casting.

To use oil bonded sand you need bentone clay.
It is treated to take in oil and not water.
www.copperstarways.com/CatalogDisplay.cfm?frn_category_id=15

Bentonite (kitty litter) is for water only.
Water in the sand to make steam is way too much.
The sand has to let air through it.

The "Moon Sand" cost to much even if it did work.
Could be good for pattern makeing, DK.