A paint removing gun... Be carefull though, if you hold it in one spot too long I would worry about cracking the glass. In fact I take it back, go with some Aircraft Paint remover. Its a spray that melts paint like youve never seen. Only thing is you will have to then clean the tank intensly to remove all the hazardous chemicals. Still will save you a ton of time though all you have to do is spray and wipe.