Rust inside Mk3 tank

My mk 3 has gradually developed quite a rusty tank inside and conventional fuel filters are not fine enough to stop the oxide getting into the cab and making it very 'spitty' especially at high revs and under acceleration. (has anyone else had this experience?)


How can I deal with this? How does one treat the rust? There seems to be all sorts of theories about this. Not sure I want to line the tank especially - can the rust be chemically treated in the tank?

Regards


Luke

Vinegar soaking in it for a couple of days will remove surface rust.
Do a thorough rinsing of the tank with water then use a hair drier or compressed air to dry it.
Quickly fill it with gas or spray a coating of wd-40 in it to keep it from flash rusting.

The key after that is to keep a full tank.

I have had mine soaking in vinegar for several days now and tonight or tomorrow I will be pouring it out and straining it to reuse the vinegar for a few more days. Mine has been sitting for 2 decades and is quite varnished.

I've had great results with a product called "Evap-O-Rust" that is sold at Harbor Freight Tools. Just the name makes me think of informercials, and Ronco, but the stuff works. $30 for a gallon. It's non toxic, neither acid or base, biodegradable, used by the US military , yada yada. You just fill up the tank, roll it around to different sides to let it sit, and keep doing that, until the rust goes away. After doing a tank with a fresh gallon, you can put the vast majority of it back in the gallon container, and get many tanks done with it, and it looks clean and at full strength after doing it.

I might add to this thread, when I start out with a tank that's gunky with dried gas sludge on the bottom half, and rust on the top half, I start out with with POR 15 Marine clean to get the dried gas out first. Alternating that with the Evap-O-Rust has given me very good results on those tanks that I don't want to even think about painting. Of course if you're going to do that, you can just boil them out at the radiator shop. I've just run into a number of bikes that have been painted, restored, whatever you want to call it, and then parked. Just did a tank with a beautiful new paint job, that was done over two years ago, and then it sat. I can't believe they stored it that way, but a real mess, and it cleaned up quite nicely without any drama with the paint.