Gee Mike you do know that I've slept a few time since than.
But I'm almost positive that it was the latex version of Weldwood that I used. Seems that when I first tested it Which was at least 2 yrs ago that I glued luan to foam and that I floated it in a rain barrel in the green house for 3 weeks. The luan delamed but the glue held. At that point I could pull the last of the plywood off but it still took effort it just didn't fall off.
It seems that I had to put the foam and luan together when it was still tacky and it took over night to dry. If I waited till it was dry it wouldn't stick.
The vinyl adhesive that I used was Roberts 3300 but I never did the water barrel test on it.
GAry