| I am using
Hydro-Stone plaster from United States Gypsum for my tools. USG
recommends certain mixing and drying methods to attain maximum strength
of the plaster. It seems most atms after casting plaster tools just set them aside for a few weeks to let them dry. Not wanting to risk wasting money on failed casting, I decided to follow mixing and drying instructions as precisely as possible. The dryer for the plaster tools was "Jerry-rigged" from available parts from the junk bin. A rare project where all parts were on hand requiring no money to be spent. An old in-counter 4 burner electric kitchen stove was used for heating. Two burners were removed and two fans attached to blow air into the stove chassis through the two empty burner holes. The air flows out of the chassis through the two remaining burner holes with the active heating elements. Over the larger heating element a vent was place to exhaust air horizontally in the lower half of the oven box. The smaller heating element is ducted to exhaust air horizontally in the upper half of the oven box. There is another fan in the enclosure to circulate air continuously. This is all enclosed in pieces of cardboard from boxes to make an enclosure about 48" L x 24" W x 30" H. Cardboard is ok for this because the highest heat is lower than what I like for my coffee. Drying temperature between 120 and 135 degrees is desired. The 240 volt stove is run on 115 Volts to reduce the maximum heat of the stove and allow reasonable control within my desired temperature range. Two heating elements are used, and with their temperature controls set to about 30%, the drying oven will stabilize at my desired temperature. A weather station wireless remote is hung inside the oven, and temperature and humidity data is sent to the weather station display, which can be at a comfortable monitoring position up to 60 feet away from the dryer. I am unsure how long a cast tool should be left in the dryer. Until I know more, I will give them plenty of time to dry real good. Days for small ones, maybe a week or more for big ones. |
