Fibreglass Diesel Tank in Existing Bilge

[raymctear@hotma]

We want to build into our existing deep fibreglass bilge an integral diesel tank. Our aim would be to use the current form of the bilge as the sides of the tank then create 2 ends and baffles and add a top to that all fibreglassed using the west epoxy system. Our question is that does diesel react with fibreglass and the epoxy resins that we will be using, has anyone done this successfully in the past and what design features should we think of.
Ray and Irene McTear
S/V 'C-Drfiters'

[westsail42]

I would not advise using the hull sides as an integral wall of a fuel tank. It can be done, but, should it spring a leak or if you get fuel seepage, you will never get rid of the smell and stink without ripping everything out and redoing it.

I have seen fiberglass integral fuel tanks FAIL on PRODUCTION BOATS only a couple years old. There is a multi-million dollar 130 foot mega yacht out that has a permanent smell of diesel down below, due to this very problem.

If it were something besides fuel, it might be ok.

It would be better to construct a fiberglass tank the shape of the bilge and bolt/block it in.

[raymctear@hotma]

Thanks for the speedy update and advise we too dislike the smell of diesel. We will be taking our time on the final decision of design but any other information you may come across please contact us via this forum.
Regards
Ray and Irene

[Anzo]

My 37 yr old Rasmus has the original 75 gal integral fiberglass fuel tank located directly under the engine, behind the sump, and have had no issues with it. Can't imagine it wasn't a glass tank pre-constructed and then laminated in when the hull was put together. Really makes not much sense to do it any other way.