Originally Posted by nylbfan:
I have been making up layers of pink foam trying white glue, Titebond, and latex caulk. Held in place with weights for several days, the adhesive in the interior still has not set, I only find bonding at the edges.
Gary, the glues you have been using are all water based. Although they are safe for the foam, they need to air dry and the air just cannot get in to the center of the foam sheets.
Most construction adhesives, "Liquid Nails" and other brands, are solvent based: they will dry quickly, but they cannot be used on foam because the solvent dissolves the foam. Big mess.
Several brands make a construction adhesive especially for foam. Loctite's PL300 is an excellent choice, also Liquid Nails makes one specifically for foam board, and there are others. You have to check and read the label carefully, if it does not say it is for foam board, it will dissolve your foam.
These adhesives usually come in caulking tubes, and you will need a caulking gun to dispense them.
The hot melt glue will also work, and will probably be fine for what we are doing - no need for structural strength and so on. But the hot melt glue becomes brittle and doesn't have the holding power that the construction adhesives do. Also, the foam construction adhesives have an open time, you can slide and position the foam for a while after applying the glue. They will harden overnight. The construction adhesive for foam board is what you want to be using.