I bought a brand new tank and seat for my Cota 247 ages ago but it was a bit wider than standard and so I never got round to fitting. I finally rigged up some rubber mounts and got it secured and it looks good but when I put fuel in it - it leaked from the petcock and I removed and used plumbers tape then sealant and then I had a good close look and this is what I found. I guess at some stage it has taken a knock on the petcock and now it's cracked. Suggestions please

To fix only the immediate problem:

Clean out tank with acetone

Mask tap thread with plasticene

Mix up brushing grade epoxy resin

Tip in enough to seal the area around the tap hole

Move tank around enough to make sure the problem area gets a coating

Allow to cure

To protect the tank from modern petrol and fix the crack:

Clean out tank with acetone

Mask vent hole and tap hole to prevent blockage

Mix up 300-500ml brushing grade epoxy resin

Tip in and rotate tank until whole inside surface is coated

Allow excess to drain out the filler hole as it cures

Thanks David

Thorough as ever - I have two serviceable spares so I will take my time and use the second option and do the full job. Any particular brand or product or are all brushing grade epoxy resins suitable for the hostile environment inside a fuel tank?

Cheers

I have used two different brands of brushing epoxy inside three or four Spanish trials bike tanks and they both worked fine. I can't remember the name of the first lot, but the last lot was called "West System 105 Epoxy Resin" and I bought it from a local boat repair shop.

I would think that any 2-pack brushing epoxy would be modern-petrol-proof. You can look up the properties of epoxy resin on the internet if you want to check.

All done - I left the epoxy to cure for 3 days then put some fuel in last night and everything is good - no leaks so at long last I have fitted and tried out my new tank and seat setup and I think it will be a great improvement in comfort. Thanks again for your help.