Liquid Nails LN-990 Ultra Qwik Grip Adhesive 10 fl. oz.

No, attaching pre-finished polystyrene quarter round to pre-finished polystyrene baseboard with LN-990 isn't a good idea unlike I stated in the previous post. LN-990 does hold them together fairly well, but the glue cures into a flexible seal, and it looks a bit precarious in a single bead on that plastic finish, which hasn't been sanded. A thin bead of Loctite Power Grab Ultimate (and only that one) is the way to go in this case, but the initial grab of the latter glue isn't as strong in this case, so an occasional finishing nail through the quarter round and into the baseboard is needed even despite the seal eventually being stronger than the polystyrene itself. Just wanna prevent you, dear reader, from making a mistake. I actually tried LN-990 on two little pieces of that baseboard and that quarter round first, so I avoided a trouble there. Otherwise, LN-990 is absolutely a way to go on trim of all sorts against drywall and for other surfaces like that and on much heavier things: it does grab right away and holds impressively, very occasional and sparse bracing/nailing is needed in very extreme cases of very-very uneven surfaces only.

Seems ok, the drying time is 16 hours at room tempreture, as stated in Tech data.