Hello, I have been using J-B Weld for the the bottom and sides of the tanks for a number of years on a few lanterns and it's kinda like bondo as used on cars. It has a part-a and part-b that you mix and after it dries you can sand down on it and feather it out. Also as it is stated on Woody Kirkmans lantern site I have used U.S.Standard Por-15 for the inside of the tank. Works great. J.B.Weld for the big holes and U.S.Standard for the pin holes. Apply the Por-15 3 to 4 times and it will never leak. Allow the Por-15 to set for 24 hours then repeat the treatment. Works wonders. Steve.