B31 Fiberglas Gas Tank

[dabroand]

Hello Everyone,
Need some advice on fiberglas gas tank. I have a B31 with the original fiberglas gas tank. The boat has been sitting on the dry for 20 years. I am re-doing the boat - stripped it down to the hull - new paint - new interior- new engines. I think I am going with the Cummins 220's so I can keep the same shafts. Can I use the the fiberglas fuel tank ? Anybody have any insights to share ??? also, does anybody have any advice on engines?

Thanks
Captain Andy

[Rawleigh]

If it hasn't had ethanol gas in it I would clean it and reuse it. Open it up and look inside for any flaking. just my opinion. I know others will disagree.

[Tony Meola]

When I switched over to diesel engines I kept the fiberglass tank. Since it sat for 20 years I would think the tank has a gunk from old gas sitting in it. As said take a look inside through the plate on the top.

How many gallons is it?

[Snipe]

I am also refitting my 31 and plan on using the original fiberglass tank and I ran ethanol gas in it. My boat is a 77 FBC. I took out pick up tube plate and fuel fill plate and cleaned the tank and inspected looked great for a 41 year old tank. No ethonal damage I could see. My dad had a 1962 and his tank failed due to ethanol. So I think some failed and some didn’t . I am sure the guys will chime in on this. If you run diesel in the fiberglass tank it will last forever unlike aluminum tanks that pit and corrode over time. If you want pictures of both jus pm me.

[Carl]

My tank only got screwed up from running 10% ethanol on a steady basis. Used to be a winter mix that looking back used to give me some problems...but mysteriously cleared up each Spring.

First year with full ethanol boat ran great running around enjoying the boat with new tranny ratios...went in to get so go go juice and couldn't make it back out...limped home with motors stalling.

Point being E-10 attacks fast. If boat was laid up before E-10 was in...I'd say no harm no worries, if tanks good and sound it will be just fine going diesel.

Dad had a Hatteras with gas motors and glass tank that started to have issues before converting to diesel. He cleaned tank, filtered and pulled out lots of stuff...flakes, thinking gel coat. He didn't know about the E-10 eating tank till after he was done...anyway he converted using same glass tank and its gotta be 15 years and tanks still fine.

So...no E-10 in your tank...you should be good going diesel. I say should as some glass tanks just don't last a lifetime.

Good luck on your project,
Carl

[Yannis]

You will never know whats going on in your tank unless you make one inspection hole per baffled compartment.

Takes some time but you can then inspect AND clean your tank as need be.

[dabroand]

All,
Thanks for your help!!!!

Capt Andy