I'm considering the purchase of a 1981 GB49 trawler and have noticed
that some GBs of this vintage have had fuel tanks replaced. Does
anyone know if this is a common issue, or what the average tank
longevity is? I assume some major structural work has to be done to
replace the tanks.

Are there any other known issues with GBs of that vintage?


Black iron tanks can rust out.
Less risk if:

1. bottom of tank has some airspace under it. (Is tank supported on corners and
some edge blocks or sitting directly on a floorboard?)

2. Fuel hose enters tank through side, rather than down through top. Prevents
water following the hose from puddling on top of the tank

3. Deck has never leaked over the top of the tank

4. There is no history of any great quantity of water in the fuel separator
(difficult to establish when looking at a used boat)

You will likely have to pull the engine (s) to
replace the tanks.

Teak deck? The usual drill.......make sure water hasn't followed the screws
into the deck coring.

And then look for all the other isms of older
trawlers....less frequently encountered in a GB but still potential issues.