Did you get an
offshore 39? Your tank construction is probably pretty similar to mine, i have an 1979 Offshore 38 Richards Design.
As far as I know, my diesel tank has not had any leaking issues, although there is a spot on near the top that looks like it has been patched with glass. The solution I decided on to deal with this issue is to keep and use the original tanks as-is but also to install additional tankage. I'm installing a 40 gal water tank in
stainless steel and an additional 35 gal diesel tank in
aluminum.
This will put me at 140gal water and 70 gal diesel total. I think i will get to avoid drinking out of the fiberglass water tank for the most part. 40 gal should be able to provide the primary
drinking water and with a
watermaker it should be easy to keep that topped up. The integral glass tank water could be used for
laundry, showers, misc as well as backup if/when the
watermaker fails. I needed the extra tankage anyway as I hope to do some long distance cruising
Thats my plan anyway. The way my
fuel tank was created (built down deep in the keel) it would be possible to cut the top out and create a template to have an
aluminum tank made, (though this would not be a fun task) i would imagine loosing a fair amount of capacity though, and having the tank down in the
keel, i would imagine it would be easy to get water trapped along side of it possibly causing
corrosion.