Norvel tank mount

I personally don't care for these mounts myself as they really put the engine way out. When I first was introduced to these engines I used them. Norvel made two styles of tank mounts. The one I have which I was looking for is rarely seen. I have 4 of the Norvel 102100 style which I believe is what you own. The backplates fail with regular frequency on these. I inflate the tank which quickly shows the leaks.

          There's a few things I don't like about this tank. The pickup isn't in the corner, it's about 3/8" off the side wall . This leaves fuel in the tank at the end of the run always. It really is difficult to remove the remainder and this is a reason the tank back fails. In addition, the pickup height is low to center line of venturi, therefore if you go inverted, the engine run richens up and does the opposite when upright. When the pickup isn't centered, this also can shutoff the engine do to a hiccup if the pickup starts sucking air. The pickup is also jammed hard into the backplate . I prefer a bit of a slash cut opposed to square. However, seeing that it is at a slight angle to the backplate, it's not really choking it off. The other major source of leak is the push button vent. If you grab the assembly and wiggle it, it will pull out in it's entirety.

             I use JB weld many times and while some claim it doesn't stand up to nitro fuels, it does for me. Now I never immersed it but I think once properly cured it would stand up. I know a few who were using 35 mm  canisters for fuel tanks and were using Goop glue which is pretty different stuff almost silicone rubbery like but might just work for these applications.

           You mentioned a o-ring possibility. I believe this would be a bit of a challenge with the tank I have in my hand here as the backplate is completely flush. This would require the shoulder to be deepened to accommodate the thickness of the o-ring. How would you compress the o-ring to provide a seal without anything mechanical other than adhesive to retain the backplate? At this point it would make sense to just find a adhesive that works with the existing.