My 1964 BMW R60 tank has beautiful patinated original paint but the original lining inside is in bad shape.  I have been trying to remove it ( there is some rust as well)  but was recently suggested I try a shop in Toronto on Martin Grove called Gas Tank Exchange. He had his R90S original paint tank relined and it looks like they did a good job. I am looking for any other recommendations of places that do this closer to Kingston/Ottawa OR would like to hear from anyone else who has had their tank done there. I have used Caswell on other tanks but this is a complicated tank with an integral toolbox and I don't want to take a chance.

I had a leaking car gas tank repaired and lined there, they did a good job, and the repair was successful, but your problem is a little different. It sounds like your tank has been lined previously, and you are looking to remove that lining and re- seal it?  I had no real success removing old sealer from my Triumph tank using lacquer thinners,  and my searches online revealed many owners who also had to give up. That stuff is difficult to remove, particularly from the parts of the tank you can't see or get at.  If removal is possible, I don't think it's a job for the average owner, and professional help might be the only way, if you can find someone.                                                                                                                                                                                                                                                                                                                                                                                              

Now I am glad I asked ! I have also read that acetone works but will probably try MEK first. Thanks everyone for the feedback. Much appreciated.