Process With Photos of Removing Old 1976 36' Ethanol Exposed Tanks & New Member Intro

[NC Hatteras]

I am looking for photos of the process involved with removing the floor & tanks that have been exposed to ethanol fuel in a 1976 36' Hatteras Convertible. I searched various words and could not locate an actual writeup or photo documentation to show the extent of what is involved.

One last question, if I replaced the existing tanks and ran the current gas engines, could I then switch to diesel in the future during a repower I assume with basically a solid tank cleaning?

Thank you in advance for any information you can provide.

Some background on me as a bit of introduction. I live in Greensboro, NC near High Point where Hatteras started and went to Naval Design school in Maine after building boats at Jones Brothers Marine in Morehead City, NC for several years after college. Part of the curriculum was doing an internship at a boat builder during Spring Break, I chose to do my internship at Hatteras in New Bern so to have the chance to breathe new life into an old Hatteras that will live on the coast of North Carolina would be great opportunity and exciting for my wife and young son.

Scott

[racclarkson@gmail.com]

Search “Watertank baffle repair”, a recent related discussion by one of our more astute participants. And welcome aboard.

[NC Hatteras]

Much appreciated.

[Boatsb]

If you replace with a tank that can handle the diesel repower yes you can. Diesel has send and returns. So do many newer gas motors BTW.


You need to tear up the deck and remove the tanks. Then have new ones made to fit, You may be able to get a few more gallons in the new tanks. Depends on the design,

[dsharp]

As you know, the fuel tanks are mounted under the back deck. You are going to have to cut the back deck and deck beams that support the deck to be able to remove the existing fuel tanks. . The biggest problem is finding a way to tie back into the deck beams for adequate strength.
It's no big deal to switch from gas to diesel. You will need to add a fitting in the tank for fuel return.

[Cricket]

So my question is could the damage be repaired by grinding off the soft area(s) or layers and then lay down new cloth using an ethanol proof resin and or recoating with an ethanol proof product after cutting the top of the tank off?
I wouldn't be that worried about getting the deck securely back in place after removal. Add or create a ledge and start glassing and sistering the deck beams back together.
My guess is new aluminum tanks might end up being cheaper in the big picture instead of trying to repair the damaged fiberglass ones, either way the deck has to come out.

[jim rosenthal]

The tanks should be removed altogether, not repaired, and replaced with FRP tanks made with resin resistant to ethanol. The only way to do this is to take up the deck and then glass it back in. Tom Slane did this with several 36Cs in his shop. He also had molds for a large midships tank which fed both engines. Aluminum tanks are one of the worst choices- they will corrode, they will leak, and they can't be inspected under there. The new tanks should be fiberglass and not an FRP repair to the old tanks.

[Cricket]

Yes ethanol proof fiberglass tanks are the the best option but the cost for new ones has to be insanely high. Most gasoline powered boats have aluminum tanks that can't be easily inspected, if at all, so I'm not understanding why aluminum is such a terrible replacement.
The outside of aluminum tanks should be coated with some sort of epoxy for corrosion protection, there are many coating options available, our custom center console's tanks are coated with a coal tar epoxy product. Many are wrapping aluminum tanks in epoxy and fiberglass for protection.

[Flying Dutchman]

You could look at what is done to repair Skater boats with ethanol related tank issues. Skaters fiberglass tanks are structurally integral, so must be repaired in place. They essentially cut the top off, clean out any damage and reline.

That being said, many also choose to replace with aluminum after the ethanol damage has been removed.

[31FlyCruzr]

It has been a while since I contacted resin companies about a resin that is compatible with ethanol. All companies replied negative, they have no compatible resin, just resistant. I have two friends with 31 Bertrams built in the 1990's and both replaced their ethanol resistant tanks this year due to getting soft. I put a coal tar epoxy coated aluminum tank in my boat.