Aluminum Chunks, Small, 1 to 3 mm, Resin Exotherm Control, Embedment.
This is an ideal filler for anyone making large sized resin castings. It will help control the exotherm (heat created by chemical reaction as resins cure) of any casting material, usually resins like epoxy, but also polyesters and urethanes. Originally marketed as an epoxy filler for pattern makers who make match plates and other types of patterns (and molds) used in conjunction with foundry casting. Over the years as thermosetting polymers improved, pattern makers started switching from materials like wood and metal to epoxy and urethane polymers. Epoxy and urethane as a casting materials for patterns were good because they had high strength, could be cast into large cross sections if steps were taken to control exotherm, were forgiving (mixing proportions could be adjusted so the 2 parts could be measured by equal volumes instead of weight), and of prime importance, they had practically zero shrinkage....(see more)