Silicones and Craters

摘要

Silicone surfactants can be extremely useful in solving crater problems (particularly those in clearcoats) and at the same time are notorious for causing craters. I have worked in paint plants where silicone materials in any form were forbidden and auto plants where they were equally unpopular. To be fair, paint and auto plant problems have often been tied to silicone paints, caulks, and sealants used by contractors and silicone gaskets installed in paint pumps or air systems rather than silicone surfactants. However, silicone additives must be used at very low levels (in the range of 0.01-0.1% on total paint) and with considerable care. If a little bit is good, more rarely is better or even necessary. Only a very little silicone is needed to cover a surface (in theory, a monolayer would suffice). Suppliers usually have good knowledge of the products and levels that are effective in different paints.