I’m restoring a 911S that has been sitting for 15 years and just pulled out the gas tank. Needless to say, the fuel was heavily varnished and inside the tank filled with rust sediments. Washed it out several times just to get the loose stuff out of the tank. Then probed it with a borescope to see a patina of orange rust dust and some scaling that was pretty consistent all over the inside. Thanks to the factory Wurth coating, the outside is like brand new.
My question is, what is the best product and procedure for removing as much of the rust that I can and then to seal it. I noticed that Eastwood has 2 rust dissolvers, its own brand and something called Oxisoly. Since I cannot really get inside the tank to wire brush or scrub, I will have to pour one of these products in, shake and drain. But which one is better and how much should I use? I have to coat the top and bottom of the tank to remove all the rust. So do I keep this stuff inside the tank, shake every two hours, and then leave it ovenight, then turn it upside down and let it sit for another 12 hours?
Also would like to hear from anyone who has used the tank coating kit from Eastwood, any problems with the coating breaking apart after a few years etc. Thanks Allan