I'm bringing this post back up because I'm working on a terrarium that may involve the use of painted foam (specifically, pink insulation foam) to construct the hardscape. My idea is to shape out the foam, paint it with acrylic paints, then use some kind of waterproofing agent to protect the paint from misting damage, if it needs protection at all.
My concern is in this passage:
Yeah, I believe you can definitely seal foam adequately, to ensure animal welfare as far as toxicity goes. This I mean in terms of the foam itself, plus the sealant, plus whatever tinting you need to accomplish. I like 100% epoxy solids products. No VOCs, less layers to apply so less concerns with delam / bad adhesion, and you get a quick cure. Acrylic paints I trust, atop the epoxy, not as a substitute. Also the mineral dry tints (though the color options are very limited).
Bolded part is what I'm concerned with.
I'm not sure if this means that acrylic paints must be on top of the epoxy sealant, or if "atop" means "in addition to," in which case the epoxy sealant can be on top of the acrylic paint.
I'm sure I'm overthinking this, and I'm not even sure if acrylic paint is endangered by misting. But I want to make sure before I go this route.