Fuel Tank Sealer

Hi Everyone,
Has anyone had experience using fuel tank sealers, I'm interested in a D.I.Y. product as I can not find anyone in our local area to do it.
I'm worried about how it will go getting around the baffles in the tank (the tank is off an E27N Fordson Major).
To be honest I don't really know what the configuration of the baffles are.
The kit I'm interested in is a three step (cleaner, etcher and product).
I should say I don't want to use the sealer to fill holes but rather just to "clean up" the inside of the tank as it has been sitting out in the weather and is now rusty inside.
Any help is much appreciated,
Chris

I used this on a rusted motorcycle tank with great results my advice is to follow the instructions exactly It takes a few days to get the job done and you have to turn the tank often to get an even coverage also block up the fuel line hoses with wire or rag that can be removed later this stuff sets hard use all three products even if you think you don't need too