Bad luck Ray!
This reminds me I was going to show you my leaking-tank fix. It was split just below the bushing that supports the air filter box. Not, I hasten to add, because I'd used an overly-long screw in the hole! In a previous post, (air filter mods, or somesuch), I described the new bracket I'd made to support the air filter, so that the tank bushing could be released from that duty.
Trying to plastic-weld the split did not seem likely to be successful, and I knew from my split Cagiva Canyon tank that I discovered the same week (!) that putting a patch of epoxy on the outside was not likely to hold for long (I was dead-lucky to find another perfect nylon Canyon tank on ebay immediately
).
For the Dart I aimed to seal the leak with flexible fuel-proof gasket sealant, held in place by a patch that was supported by the now-redundant air-filter support bushing. I built a GFRP patch all around the split part of the tank and when it was cured fully, pealed it off the nylon, and drilled the bolt hole. Then I sprayed it and the tank with several coats of Hylomar sealant, which is everything-but-acetone-proof and stays flexible, coated the bolt with the same and attached it to the tank. I left it in the sun and progressively-tightened the bolt as the sealant settled, until I thought it was as tight as I wanted to risk it. So far, so good! Given that the Hylomar will keep the fuel in, I'm not worried about the glass-fibre resin being affected by alcohol, but I guess it would be possible to use a resin that was proof against this effect.
