The tanks were completely stripped back to bare metal so I could see if there were any pin holes. I pored methylated spirits into them and sloshed it around and there was no sign of a leak. Why metho? Well it is very fluid and will quite quickly get into any seams and escape to the outside. It then evaporates quickly as well.
The underside of the tank before treating. You can see how well the molasses works No sign of rust anywhere.
POR15 filling the rust pits.
A coat of POR15 was painted onto the outside of the now right tank and then the tank sealed inside with POR15.
Regards Rick.