I have used KREEM in my bikes and have been extremely pleased. As mentioned in the other response, cleaning your tank prior to using the liner is the key. As a matter of fact, the cleaning step is as critical as the coating step.
I have also spoken to several "old timers" regarding sealing a tank and they all agreed that KREEM is a fantastic product. They have bikes that were coated with KREEM many years ago and they haven't had any problems. But of course all of them said the same thing... Theycleaned them well first.
If you visit
www.kreemproducts.net you will find a "How To Video" on their home page along with a lot of information regarding their products.
Again, I have used KREEM and am very happy with it!