Originally Posted by Lay'emLow
...does anyone have any tips for a first time tank builder? I realize that my welds must be impeccably solid. Is there some kind of substance I can pour in the tank after building, swish around and let dry to ensure a good seal? This could even double as a finish for the bare metal on the inside of the tank (is that even an issue of concern?)...
Good luck dude...
Make sure you have good, clean joints and welds... when you're done, put some water in the tank and attach a pressure hose to "pressure test" it and make sure there are no "pinhole" leaks... if so, fix them, if not, empty the tank, dry it, finish the metal, etc. Once fab is complete you can creme the tank with a sealant. You can get tank creme in a lot of "automotive" places.
Finally, do your paint and final finish...
Hope that gives you some insight. There's an old book I have called Metal Fabricator's Handbook
that has good info on building tanks.