I've been having quite a lot of trouble with the Plastic tank swelling on my M1000, the only cure for which appears to be airing it for a few months without any fuel in, so having two tanks I've been swapping them out every 6-12 months.
I really don't like the thought of trying to coat the inside, as whatever you put in is REALLY hard to get out again.
A couple of years ago I brought another tank from Slob, repainted it, added new Decals, then decided the Satin Black look I'd gone for wasn't actually that great, but have been using it on the bike as above.
Then on Friday when the sun was out I tried to take the bike out for a ride and found the fuel pump had given up the ghost.
I took my 999 out for a ride instead, but decided as the tank had to come off anyway, and the tank had swelled again, I might as well swap the tanks over.
the tank on the bike was the original with the original paint.
I must admit I was a little shocked at just how much bigger the old tank was this time, but unfortunately I think I've left it too long because the paint on the old tank has blistered really badly, even in places that don't always have fuel directly behind them when on the bike.
I say blistered, but they appear more like pimples, and are hard. I've not tried too hard to pop any as I don't want to break the paint layer.
Strangely they appear to be in lines in places.
Is this normal?