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

[NC Hatteras]

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

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]

Re: Process With Photos of Removing Old 1976 36' Ethanol Exposed Tanks & New Member I

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

 

[NC Hatteras]

Re: Process With Photos of Removing Old 1976 36' Ethanol Exposed Tanks & New Member I

Much appreciated.

 

[Boatsb]

Re: Process With Photos of Removing Old 1976 36' Ethanol Exposed Tanks & New Member I

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]

Re: Process With Photos of Removing Old 1976 36' Ethanol Exposed Tanks & New Member I

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]

Re: Process With Photos of Removing Old 1976 36' Ethanol Exposed Tanks & New Member I

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]

Re: Process With Photos of Removing Old 1976 36' Ethanol Exposed Tanks & New Member I

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]

Re: Process With Photos of Removing Old 1976 36' Ethanol Exposed Tanks & New Member I

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]

Re: Process With Photos of Removing Old 1976 36' Ethanol Exposed Tanks & New Member I

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]

Re: Process With Photos of Removing Old 1976 36' Ethanol Exposed Tanks & New Member I

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.

 

[UNIQUE_NAME]

Re: Process With Photos of Removing Old 1976 36' Ethanol Exposed Tanks & New Member I

i had looked into new glass tanks when i did this (2006). insane is a good description of what the cost was.
i also looked into moeller plastic tanks but at the time they didn't offer any tank large enough.
aluminum is what i went with and the exterior is coated. i think it was powder coated but i would have to dig up the paperwork to verify what was used.
everyone i know who went thru this, ended up with aluminum. for all the sportfisherman boats the back deck had to come out too..

 

[Dazed338]

Re: Process With Photos of Removing Old 1976 36' Ethanol Exposed Tanks & New Member I

Have a 1967 31C PO had an Aluminum tank installed, it appears to have been welded up in Hull.

 

[Boatsb]

Re: Process With Photos of Removing Old 1976 36' Ethanol Exposed Tanks & New Member I

Most aluminum tanks corrode from the inside out. Gas with ethanol is hydroscopic.

 

[Cricket]

Re: Process With Photos of Removing Old 1976 36' Ethanol Exposed Tanks & New Member I

Hopefully one of the larger tank builders might already have drawings for the 36 from previous jobs.
The only 2 I know about are SP Tanks in NJ and Florida Marine Tanks, have to be some others as well.