Hey guys...what am I missing here? I used ProBond polyurethane glue to repair my Robart airplane cradle, which is made out of some kind of "foam" material....big mistake...it disolved the foam cradle! I assume that there must be different "foam" formulations, but how does one know which foam is safe against polyurethane glue? From a different aspect...WOW, 500 pounds of weight...on my building table...heh heh...I dont think so! I am resonably certain that even if I felt inclined to attempt lifting all those sandbags, or whatever, my back would give up under the strain nearly as quickly as my building table. I like the vacuum bagging method. They use that in the commercial layup of fiberglass boats, etc. As for the adhesive...the polyurethane does exert a great force as it expands....which is great in driving the glue into cracks and gaps, but also the expansion force trys to separate the glued pieces. I find the polyurethane glues fine for rebonding the legs and other spindles on the chairs and such. The expansion really makes the joint strong and wiggle free, but it must be clamped together during the curing, or the spindles will be driven out of their holes. In the old days, pattern flyers trying to obtain the very lightest weight, would use some sort of glue called "sorghum paste" for sheeting their foam cores. I believe this is a grain based product, akin to flour and water, but much stronger. It was cheap, and didn't attack the foam, and they said it was lighter than epoxy. I don't hear anything about it these days though.