Simple step by step instructions and sources for ingredients. Your goal for good greensand is a clumping function so that it will hold it's shape easily. This is accomplished with bentonite clay powder which is the same ingredient that clumping cat litter uses. It has many industrial and health uses but you want to make sure your bentonite is a find powder. I picked up the Bentonite from http://www.foundry101.com at a reasonable price. I used about half of it to make this batch of greensand. I store my greensand in a plastic tote it a sealed lid.
The other dry ingredient is silica sand which I ended up getting from Carquest Auto Parts. It is used for sandblasting. It was not as fine as I hoped but the results were very good none the less. I have found playsand to be unacceptable coarse and don't suggest using it.
The final ingredient... the water! It came from my sink. I am using a simple hand pump pressure spray bottle to mist the water for even distribution then folding and mixing using various methods. Mixing well is absolutely critical. After I made this video I learned that covering the sand with a tarp and stomping it often during the process will help improve the quality of the final product.
The better quality the greensand the better your molds and final casting will turn out. Once I made this actual greensand my metal aluminum casting projects escalated to a whole new level. I also built a set of reasonable quality casting flasks which I will make a video about soon.