BCS Aluminum Degas Tablets are a professional grade, low smoke, degassing tablet for use in aluminum casting. They are manufactured by the Asbury Fluxmaster of Utah Co. and sold under the trade name of Asbury #752(tm) to the foundry industry. This material works to effectively remove hydrogen gas while fluxing suspended oxides and other impurities from the melt. It is designed to release a greater number of smaller gas bubbles over a longer period to give the most efficient cleaning with a minimum of smoke and fumes.
Molten metal can have gas dissolved in it that can cause problems. This gas is usually hydrogen. Dissolved gas can cause surface imperfections when the gas comes out of solution (bubbles) into the sand. It can also lead to serious metallurgical defects caused by hydrogen embrittlement and internal porosoity.
Degasser combines with hydrogen in solution in the molten metal, and drives it out of the melt.
Only a small quantity is needed (see chart below). Dosage required will depend on gas conditions of the metal, but typically 1.75 ounces will handle 100 lbs of metal. These tablets will need to be ground or divided up for use in smaller amounts.
For small batch use the following amounts are recommended: