Outer Limits 4x4 Board

Old tank has got a new series of dents so I've decided its time to swap in the spare tank. It has been sitting in the shed for a while and some dust/spiders could have got in through the filler neck so what is the best to go about cleaning out the tank to make sure it hasn't got any contaminants in it? John.

I would try a few litres of petrol slopped around...and then poured out...repeated several times.

If it still has flakes coming out after a few goes, then I guess it will need to be steam cleaned.