I needed to make a viewing port in my common sump by bonding 6mm PVC to 2024 T3 aluminium.

Does it stick? I make up a test piece as you see in pic 1. I am using EZ epoxy. The PVC is 6mm thick, I routed a 3mm step into it and primed with a commercial PVC primer which is really MEK and acetone combined. I roughened the aluminium surface with 40 grit sandpaper and cleaned with acetone.

I painted the surfaces with pure epoxy and then mixed up flox. I bonded the two surfaces, clamped them and left for two days to cure.

Pic 2 shows that I have put the joined pieces in a vice and hooked a weight measure device on the PVC and applied a shear force to try and break the bond at the weakest point.

At between 20 and 25lbs I was bending the .080″ 2024 and still the join held! I measured up to 26.5lbs which took a lot of fulling force. Somewhere between this and 30lbs the join failed.

That is seriously strong! Pic 3 shows that the join failed cleanly at the glue line. I also noted that a bit of glue that squeezed out onto un-sanded aluminium and unprimed PVC failed very cleanly suggesting how important prepping the surfaces is.

Test piece

Shear 26.6lbs OK

Failed