Been doing some work on a Foam mountain to be placed where I took out the Refinery. It will be about 15ft long when finished. & about 8 inches deep & about 18" tall give or take a few inches. An automobile tunnel at both ends.
The initial glueing all of the blocks of Pink & Green Foam together took about a week to dry. I also attached them together w/wood Skew sticks so the foam wouldn't bow. I use to use long nails & then pull them out when the glue had set, but, now the skew sticks work a lot better. You don't have to take them out.
Then the other day I started grinding down the foam w/a 4"Angle grinder.
Then I did some more work w/a dremel tool & then cut slots for the Pinebark & glued those in. I figure about 3 more days & all of those will be dry.
Then fill in all the gaps w/latex caulk, flat black wash, color the rest, add foliage(oops getting ahead of myself) more later.