[wrndln]

If the tank is removed for restoration, like many are, why not stand the tank on end and fill the tank about half full of rust remover (Evaporust or whatever). It will only take about 5 gallons of rust remover to do almost all the tank if you flip the tank after letting the solution do its work on the first half of the tank. There might be a very slight amount of the tank that might not get derusted in the center. That would save some serious $$.
Rusty Nelson