ive seen in several posts about getting bubbles out of resin casting..this is new to me so i thought i would try it, but, ive looked at every bottle in the store and none of them make any reference to having or being free of silica..so how do i tell?
Hi Trooper, I use regular Johnson's baby powder (didn't bother to look if it was silica-gel free - didn't know that) and it works fine. Make sure you keep the bottle always tightly closed as humidity makes the powder grainy which can lead to loss of cast detail (hmmm... maybe that's what the silica gel you mention is for - it probably has larger grains but keeps the powder dry).
Anything with talc has silica, corn starch based baby powder has none.. I prefer corn starch as it makes painting the piece easier, I've found talc based products sometimes give you trouble with fish eyes and adhesion problems.