Wyldes of Leeds do an ethanol proof tank sealant I have used on a 1919 Hobart (steel) tank which looked more like a colander than a petrol tank with no problems, and on my ISDT fibreglass tank which had a previous loose tap for as long as I have owned it but has now started to leak- but I run the Greeves on non ethanol super by testing it to see if ethanol is present- watch this space.....
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