Thanks guys. I can't use a bolt because the holes were drilled by the PO to attempt to seal a leak around the sender unit and the bolts/nuts would interfere with the sender. I fixed the original problem with an under-ring but when I press down on the tank, I can't hear a minute amount of air coming out under the sender gasket
. I'm probably being anal but I don't want a problem when the boat is heeled.
The thought of heating
the tank up enough to melt the poly makes me nervous. Seems like I could easily make the problem worse. Is it hard to do a plastic weld?