I know I said I’d treat the inside of the tank before doing the outside but I changed my mind, and started treating one half (the top half) of the fuel tank. First I gently used a wire brush to remove surface rust (carefully so as not to stick a hole in the tank).
Then I painted the top half with a rust eater product, initially it turns purple but overnight it will turn black.
Here’s another view of it.
And the following day it looks like this.
Next, I painted a zinc based ‘anti rust’ paint on that treated area. I did not remove the 6 protective pads as they are glued onto the tank and more than likely are protecting it anyway as they are covered in tar.
After painting on the zinc paint, I decided to close off all the tube outlets and the fuel sender hole in order to ‘seal’ the tank so it won’t leak when I do treat the inside. For the fuel sender hole I cut a slab of 2mm thick rubber shape and cut holes in it to match where the bolts protrude from the tank, and then laid a few rubber strips on top of it.
Next I placed a flattened bottle top and used some steel from a broken window scraper. After drilling holes in that broken window scraper, I could form what I hope is a tight seal by holding it down with 5 nuts. Yes it looks crude, but hopefully it will do the job.
Next I used more rubber and cut fingers out of a rubber glove with some tie-fasteners to close off the exposed tubes.
So now the only entry/exit point into the tank is the via the main fuel entry tube, which is where I’ll pour the Muriatic acid once I’m fully prepped and prepared.