Hi - I am just in the process of replacing my Spitfire glass tank with a metal one. I have tried lining 2 Commando tanks before without success. It seems that once ethanol petrol has been in a glass tank, the ethanol gets absorbed into the structure and it is too late to line it. Best to bite the bullet and buy a steel one from India. I can recommend a seller if you want to go down that route.
Regards
John.
