Petrol Tanks

Hello Nigel
Back in 2021 I needed some repairs done to an ebay Slimline tank, bought cheap and rough. At that time, the NOC Services pages listed a company called Heritage Motorworks Ltd, run by a very helpful gent by the name of Drew Roberts. He did an excellent repair on taking out some severe dents, when I went to collect it he told me he had pressure tested his repairs (which were fine) but also revealed some previously unseen pinhole weeps on that rear seam, so he’d done those as well before handing the tank over. I was so impressed I got him to do some frame and mudguard welding too.
I think the business has changed hands, it now appears on the Services page as Metal Magic. Same phone numbers, slightly different address.
Location is Buster Farm, Brickhouse Hill, Eversley, Hampshire England, RG27 0PY Give them a call and see if they can help.0118 973 1631
Or Email metaltel@yahoo.co.uk

Metal Magic is the place to go. The proprietor specialises in Norton tanks and always does a first class job.
Recommended.

I would prefer a good weld over a tank liner, so my advice would be to follow the advice above. However, I once had a (Montesa) tank with original paint where petrol came out from behind a welded-on tank mount. I did have it welded as carefully as possible as to not damage the paint. After two tries and still leaking, I took my chances on an ethanol proof tank liner, which still holds 5 years after application. 

As I've just posted elsewhere, you can get a perfectly good leak repair by using plumber's solder.  Or use JB Weld epoxy.  It will outlive you I expect!