Which weldable material to use for drybag subject to abrasion?

I have been thinking and wondering about the same question, for a beach-cruising sailing canoe.  So far, my best guess has been to use a light nylon packcloth or similar bag (sewn) for the abrasion resistance, with a welded drybag liner of vinyl or polyethylene.  OTOH, one of the heat sealable nylon fabrics such as http://seattlefabrics.com/Heat-Sealable-Nylons_c_80.html might do the entire job but I know little about the durability of the heat seal and coating with those fabrics.  I will be looking for other comments as well!

— Sam

I just made a pair of conical dry bags for the inside of my whitewater kayak from heat sealable 70 denier nylon. I consider them temporary. In my experience, heat sealable nylon like the stuff sold by Seattle Fabrics has pretty poor tear strength and fair abrasion resistance. It might last one season. My recommendation is to forget about welding. Manufacturers are able to make strong welded seams with ultrasonic welding equipment. I’d suggest bonding the seams or sewing and sealing. It will be stronger and you will have many material options.

Thanks for your feedback on the heat sealable nylon, Colin.

— Sam

If sewing and sealing, Xpac VX33 and VX50 (multi cams) have a polyester film inner lining that takes well to sealing. The much cheaper X21 RC fabric has the same poly lining as well with the 210d nylon face.

– greg

Thanks for the replies, everyone. I should have stated that the bags are for a commercial venture….with me acting as the designer. I’m now helping the company who will be marketing the bags choose an appropriate material. Manufacturing options will only be limited by material. (that said, hope I have not violated any rules here)

Thanks!