Cleaning/Sealing 83-84 Gas Tank

Not much on the early tanks so I'm making a thread to address it.

Been trying to clean out a tank for a while now but the last patch of rust i can't get at around the gas cap bevel area. Since the gas cap doesn't seal all the way [how it was designed apparently], need to figure out how to seal gas cap area so it can be soaked in solution.

Pin holes along the lower seam and bottom of tank started to show up; so anyone trying to skip sealing and just want to fill the tank, put over a tub and let it set for a few hours / a day with gas to confirm all is okay.

 

I gave up trying to clean out one of my '83 tanks that was badly rusted and gummed up from sitting with gas in it after I saw a picture on here of someone who cut open an old tank. There are two convoluted tubes inside that would be impossible to clean out. My tank had a dent anyway and would have had to been repainted. I have a second tank that I started to fix up in 85 before I bought a replacement bike for my first one. It had a dent I filled and I started to prime it. Minimal rust inside and not gummed up. How is your sending unit for the gas gauge? very fragile, took mine apart and cleaned it, and got it to work. Then a month ago I bought a tank from an 85 that was pristine, almost like new, so I bought the rest of the matching body work from him too all in great shape. If anyone is interested in the primed tank, send me a PM. Other tank could be salvaged by someone who has the facilities, but it can't be shipped with the residual gas fume in it.