Hello Brad,
I have in the past used a 2 part adhesive from Hienkel. This method eliminates bubbles and high curing Tempratures
Unlike epoxy, the 2 part adhesive, each part is applied with a brush to each surface as a paint (one part to surface to top PCB and one part to the bottom surface).
Only a small amount of each is required to bond the treated surfaces together, vis; paint the surface, then use a smooth rubber squeegee to level the layer.
In this stage hold the top surface to the bottom surface edge to edge into the final position at an angle of approx 20-30 degrees and slowly "Roll" the surfaces together.
Clamp the surfaces in together a vice using a few bits of melamine board (high density chip board with plastic laminate, the stuff used in the kitchen and household furniture)
The required setting time is 30 mins, but I leave it for a few hours or overnight.
Heat is not a problem, this is evident by a touch test-about the same as a cooled cup of coffee
Hope this helps, chester.
PS if you are interested, I will look-up the product ref number