Thanks for all the help! I used the Por-15 gas tank treatment kit. Was a little skeptical at first, the amounts they send you don't seem like there is enough to do the job. But it worked great. I had the advantage of being able to use a high pressure steam cleaner also. Tank was not real bad to begin with,no holes etc. Just a lot of crud and gum inside. I still went ahead and sealed it, and it looks fantastic. Would highly recommend the Por-15. Again thanks for the help.