Your water to investment ratio is dependent on what type of castings
your are trying to make. For large castings typically 38 parts
water to 100 parts investment, medium 39, and fine casting 40.
Since I do not know the volume of your investment mixed, I can only
offer an idea of the amount of investment needed and you can
reference the existing chart you have.
Flask Size 2" x 2.5" and 2.5" x 2.5" you will need less than one
pound of investment per flask, my suggestion go with 1 pound.
For 2.5" x 3" you will need close to one pound of investment.
For 2.5" x 4" you will need 1.5 pounds of investment per flask.
As an example, if you are doing 4- 2.5" x 2.5" and you are going to
need 4 pounds of investment cross reference how much water is needed
for the ratio you are going to use. Another way is to convert
pounds into grams and multiply by the ratio you are going to use. 4
pounds= 1,816 grams X .40 (water to investment ratio) = 726.4 grams
of water. 1g=1ml
Allow your flasks to sit undisturbed for 2 hours before steam
dewaxing. After steam dewax, immediately transfer the flasks into a
preheated oven @ 300F. Do not allow the flasks to stand at room
temperature for more than ten minutes.
Michael L. Stover
Product & Application Specialist
Jewelry & Solid Mold
Ransom & Randolph