So I broke my bong and my percolator, and bowl are all fine. The bong itself is a lost cause, and the downstem shattered a little at the bottom, so it's functional but not something i'm gonna be reusing when I replace the broken piece.

I have an older backup bong that has rubber washers and very tiny downstems, but if i remove the rubber washer I can slide the broken bong's downstem in and it fits but there's no real support for it so it doesn't make a seal and i wouldn't feel comfortable attaching my perc to it. Is there a reccomended epoxy or putty go-to solution for situations like this? The gap itself is very very small, and I'd have no reservations about filling it in with something that would permanently attach the two pieces together.