I’ve done numerous tests myself with solvent and 40/42… I’ve found personally that nothing is stronger than a solvent weld honestly no matter what that paper says from Weld-On… you can try this yourself.. glue up 2 pieces at a 90* angle and let them set for a couple days.. flip over on the ground so it’s like a teepee and smash it with a sledge hammer… solvent will break the plastic and the weld is left in full tact… 40/42 is comparable no doubt but much more material is left with solvent vs adhesive glues… now if you bake the 40-42 properly it gives the same affects as solvent welding..Thanks for posting their thoughts. Without seeing some lab work shoing there's no difference in strength I'd stick with Weldon's published data. That being said when I first started working with #40 I tried breaking joints. Properly prepped joints glued with either #3 or #40 had acrylic breaking before the joint broke.