Rotten wood supporting fuel tank

thaeni

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Sep 28, 2008
120
Hunter 33.5 Chicago
I have a 1992 33.5. The wood supporting the fuel tank is rotting. Is there a way
of securing tank without removing (would have to cut tank in half) tank.
 
Jul 7, 2004
8,018
Hunter 30T Cheney, KS
Pics would help. There may be a 33.5 owner here who knows. I didn't see anything in the mods.
 
Jan 5, 2017
2,170
Beneteau First 38 Lyall Harbour Saturna Island
I’m wondering if expanding foam insulation would be suitable for that. It would spread the weight evenly and support the tank. Not sure if cutting off air to the bottom of the tank would be good for an S.S. Tank though.
 
Mar 4, 2018
34
Hunter 33.5 Southport
The only other option that I am aware of is to cut an access opening in the rear bulkhead in the aft cabin. I believe there are other discussions on this site regarding replacing the fuel tank that address the issue .
 
Oct 22, 2014
16,128
CAL 35 Cruiser moored EVERETT WA
Twenty year old aluminum fuel tank. Suspected rotting boards support of tank. what is cause of rot?

If fuel then the tank is leaking. Empty and remove.
If water than likely a fuel leak is not far behind.

For every 10 gallons of fuel you have about 80 pounds of weight. if not secured when to sail the tank will move about. It will either damage other things in the boat or puncture and leak fuel into the boat. Both scenarios are bad news.

As a DIY project it is like a 4-4.5 task requiring some careful engineering. perhaps it is time to discuss the idea with local marina repair shop.
 
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Dec 28, 2015
1,357
Laser, Hunter H30 Cherubini Tacoma
Twenty year old aluminum fuel tank. Suspected rotting boards support of tank. what is cause of rot?

If fuel then the tank is leaking. Empty and remove.
If water than likely a fuel leak in not fat behind.

For every 10 gallons of fuel you have about 80 pounds of weight. if not secured when to sail the tank will move about. It will either damage other things in the boat or puncture and leak fuel into the boat. Both scenarios are bad news.

As a DIY project it is like a 4-4.5 task requiring some careful engineering. perhaps it is time to discuss the idea with local marina repair shop.
That’s what I was thinking but pulled back due to the age of the tank. Mine took 40 years to rot out from water in the tank. The wood platform would never had rotten due to diesel saturation lol. It is comforting having a new poly tank. But I didn’t have to cut my tank out. I’d go after the bulkhead prior to cutting a aluminum tank in close quarters.I replaced all wood with laminated 3/4 plywood encapsulated in epoxy. It now holds the tank and 4 batts.
The labor was a pain but not technical. Fitting a new tank and plumbing was challenging along with re-routing accessible wiring while it was out. The new tank was a couple inches higher requiring fill hose attention with added elbows. Re-designing battery layout and building new batt cables was fun while needing to buy a terminal crimper put another tool in the box
 
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Dec 28, 2015
1,357
Laser, Hunter H30 Cherubini Tacoma
The only other option that I am aware of is to cut an access opening in the rear bulkhead in the aft cabin. I believe there are other discussions on this site regarding replacing the fuel tank that address the issue .
Wouldn’t you have to do this anyway to get the new tank in even if you cut the old tank up to get it out?
 
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Mar 4, 2018
34
Hunter 33.5 Southport
Wouldn’t you have to do this anyway to get the new tank in even if you cut the old tank up to get it out?
You would if you went with the same configuration of tank but there is an 18 gallon stock tank that will go in through the top of the compartment with some slight adjustments. Other option is to have a custom tank fabricated.
 
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