I have an older AB vinyl dinghy
and one of the valves leaks
slowly. I have a replacement valve but I cannot stretch the material around the valve hole enough to pull the old backing plate out and replace it with the new one. I attempted to replace it by screwing the external facing valve piece into the old internal backing plate. The problem is that even though the threads are the same, there is one more row of thread on the new valve so when I screw the new outer valve piece in, the gap between the two sides is too large to seal the valve.
I could attempt to create some rubber gasket
to make up for the increased gap, but it seems to me that if the replacement valves come with an internal backing and the external valve, there must be a way to get the backing plate through the hole for the valve. I don't want to cut the whole larger or make any slits because there do not appear to be many adhesives that could patch that well onto the old material. Does anyone know how these valves get changed out or can anyone offer a suggestion to fix this problem. Thank you.