classic motorcycle forum

Two years ago I had 2 tanks, one aluminium, one steel with pinholes or a leaking seam.  Everyone I talked to had horror stories about various tank sealers, single part or two part, none seemed to do the job.  The one I found which had the best reviews and was compatible with ethanol was Caswell epoxy tank sealer.  Claimed to be ok for aluminium, steel, f/glass & plastic tanks.  I gave it a try, and it worked perfectly. No sign of separation, and hard as rock.  Check out caswellplating.com.

Mike

I've just used the Caswell product for a 73 Tiger 750 tank, which was in good condition apart from one pinhole.  The resin seems OK and goes off hard, I had to drill it out of the petcock outlets as my bungs were not quite long enough.  I bought it direct from the Caswell website for around £50 delivered.  Not cheap, but cheaper than a new tank.

However, despite buying the recommended kit size for a 15 litre tank (mine's 12 litres) there was nowhere near enough for the Tiger tank.  The problem seems to be the big hump along the OIF frame tube as it substantially increases the surface area of the inside of the tank.  I think you'd need 2 15 litre kits for the Triumph tanks.

I did the work in a heated garage and made sure that everything was warm, even so the consistency of the mixed resin was like honey, so didn't run as easily as I'd expected.  You can thin it but I didn't want to risk ending up with a too-thin coating over the area I knew I had a leak. 

Having said that I seem to have solved my problem, even if only about 50% of the tank area has been covered.  It goes off in about 45 minutes at 70F and sets really hard.

I finished the job by applying a thin coat of epoxy to the outside of the tank where the leak had been, before filling, flatting and painting.