What glue for nylon to vinyl?

I need to repair an old Voyageur Shutterdry camera bag, and I’m not sure what kind of glue to use.

The bag is coated nylon. It has a waterproof zipper attached to a long patch of plastic stuff that could be vinyl or pvc. The plastic patch was originally “welded” (whatever that means) to the nylon.

The plastic patch has begun to separate from the nylon along an area about 2" long. I want to glue it.

This has to be a strong bond because I want the seal to be waterproof and it also has to withstand the shearing stress of the zipper being pulled very hard.

The only things I’ve ever used are Vynabond, Aquaseal and contact cement, but none of them for this application.

Pliobond or Barge Cement…
…will probably be your best bet, but there’s a reason that it started pulling off in the first place, so it’s possible that glue simply won’t work on it’s own. You may end up having to sew it, then seal the stitches if it’s in a high-stress area. Another option would be to add an internal reinforcement and use either pop rivets or “swat” rivets (used for leather work) to hold it in place.

Aquaseal might work, if the separated
areas are inclined to sit close together and still while the Aquaseal sets. Cotol accelerant might thin Aquaseal a bit so it soaks into the “coated” Nylon.

A long shot possibility is G-flex epoxy. It isn’t nearly as flexible as Aquaseal after setting, but if you can fair the patch a bit with the G-flex, I have no doubt about it holding.

I’ve been unimpressed with Vynabond, although it can work well in vinyl-to-vinyl bonding. But I’ve had vinyl patches come off the vinyl skin on Royalex in spite of very careful application. Vynabond should be considered a solvent for getting vinyl to stick to itself, not a glue in the normal sense.