Not sure what's happening but don't know that silicone molds always need a release.
Bubbles are normal and they should rise for about 10 minutes after pouring but not sure about their all collecting at the
bottom of the mold --is that what you mean by the "base"? Most would generally rise to the uppermost areas, gravity-wise.
(And btw, you should be able to use your breath --through a straw if you want-- to pop the bubbles after they really start coming up, or to pass a lighted match over them. Both those create the carbon dioxide needed for popping, but won't blow dust around which can settle on the resin. You don't need to pop them all right from their first appearance, and many will pop on their own as the resin heats up. A toothpick can also be used for larger bubbles.)
Other possibilities?:
Make sure resin isn't too cool when mixing (which can create extra bubbles and later cloudiness). If necessary, warm by putting the bottles into container of warm/hot water for few minutes... should feel just warm to the touch (70-85 F).
Moisture in the resin, which may come from humidity in the air or from unsealed embedments, can cause the resin or casting to be cloudy.....keep resin capped tightly when not in use.
Are you using any inclusions that might be have trapped air, or contain any moisture?
Don't use waxed cups for mixing since that can also make resin cloudy. And what are your stirring sticks made from?
Some people also recommend a whipping action rather than "stirring" to keep from incorporating too much air.
One person also recommended pouring the resin from the cup (into another container or a squeeze bottle) slowly which may reduce some of the bubbles.
Just having scratches (even hard to see ones) in a mold will cause cloudiness because the surface isn't thoroughly smooth. Which brand of 2-part silicone putty did you use, and did you make it *very* smooth (some brands, e.g., don't really end up with very smooth surfaces, like the Amazing Mold Putty I hear). It's even recommended not to "wipe" molds dry, even the HDPE ones made for resin casting, since that can scratch them --instead, air-dry.
(Will write more if other variables occur to me, but there's also lots of info on my resins page:
http://www.glassattic.com/polymer/other_materials.htm )
Diane B.
Yup! I read up about how bubbles will be normal and that with Easy Cast resin, it will automatically degas itself. That wasn't the case with me though! Yes, the bubbles collect at the bottom of the base. I am trying to make 1 inch resin domes with CastinCraft Easy Mold.
When I used my hairdryer on the resin to release the bubbles, I saw some raise to the top and disappear VERY slowly. But most hang around at the bottom and they seem stationary :O
I did warm up the bottles before I used them, and they felt warm to the touch so I'm sure I did that right! I worry that maybe with the small amounts that I use, they just end up cooling down while they're exposed to air for the 3 minutes of mixing and double mixing.
I use non-wax cups and my mixing sticks are the wooden popsicle kinds.
At the moment I can guess that the molds are probably the cause of the cloudiness and bubbles. There are probably teeny tiny scratches on them that I can't see, but it seems likely for them to be there!
