Any one have any prefered methods of cleaning rust out of a metal fuel tank ?
I have been working on my latest purchase - 1999 GPZ500S with 152 miles on the clock.
Would appear to be on its 2nd tank of fuel and for some reason the fuel tank is quite rusty inside.
I've ordered up some POR15 sealer and spent a few hours tonight shaking it with bolts etc inside then washing out with hot water in the sink.
Just wondering if there is a good chemical cleaner around.
I have a few thousand litres of hydrochloric acid and sodium hydroxide available but worry they might damage the paintwork

I have been working on my latest purchase - 1999 GPZ500S with 152 miles on the clock.
Would appear to be on its 2nd tank of fuel and for some reason the fuel tank is quite rusty inside.
I've ordered up some POR15 sealer and spent a few hours tonight shaking it with bolts etc inside then washing out with hot water in the sink.
Just wondering if there is a good chemical cleaner around.
I have a few thousand litres of hydrochloric acid and sodium hydroxide available but worry they might damage the paintwork


