H37C aluminum tanks.

[Ed Schenck]

I am starting to think about tank replacement/repair. In Owner's Mods we have one water tank project: http://hunter.sailboatowners.com/in...&cat_id=38&aid=7108&page=article&mn=37-cutter . I also know that a Search will find some other ideas. Even Richard writes that he would probably do the other tank with epoxy when it gives way. As you can see in the attached picture the tanks have a very odd shape. No way you are going to find a poly tank that will give you anywhere near the same capacity. So repair or bladder or custom build?

I don't think I have ever read of anyone removing the fuel tank. Several of us have cut cleanout ports. There is an excellent post in Owners Mods. If my fuel tank is not already leaking it is only a matter of time. With it tabbed to the hull and covered with wires and plumbing it will be quite a project.

 

[Jim Legere]

Re: H37C aluminum tanks

Ed,

I am surprised you are thinking of replacing the diesel tank. Our tanks are made from 5052 aluminum, considered to be one of the best materials for marine diesel tanks. Unless you have had water in your fuel system, I would be surprised if you have any corroision. It would only occur at the low point, which you should be able to check through that snazzy access cover you installed.

As to the water tanks, I am just waiting for the day that mine start to leak. I think I favour the epoxy coating solution for that problem, with a badder as my second choice.

 

[Ed Schenck]

I always thought the same of our fuel tanks. Then I start to read of people having leaks in their aluminum tanks. And there is no way to see anything. My concern stems from finding some oil on the surface of the bilge water. Maybe it is related to the truck trip home. I also had some oil in the engine pan. So I put some paper towels under the engine(picture). That tube in the picture is well behind the spot and is water at any rate. That oil spot is under the oil filter. . . .I think.

 

[abrownsmith]

I picked up my boat at an auction and when I inspected the tank I noticed a lot of nasty black sludge in the fuel tank due to water or whatever else. Anyway I yanked it out to clean it and noticed yep there was a hole in the bottom, just slowly was eaten away. I ended buying a new Moeller plastic one on the recommendation of all the guys in the boatyard. So yes if not taken care of aluminum tanks can die too.

 

[Blaise]

Ed,
I don't know what your future cruising plans are, but if you aren't going offshore for a long time, you don't really need the capacity the boat has. My plan for when Midnight Sun's water tanks go is to put in a thirty gallon poly tank and a watermaker.

 

[Ed Schenck]

I think if(when) I find a water tank leaking I will replace both with poly. I want more than 60 gals for resale purposes. But the fuel concerns me most.

 

[Ed A]

seems like it would be easy to tell if its leaking. there was some space arround mine.
I liked thee big tank for costal crusing it just eliminates the fuel questions but i had the big engine too.
wish i knew who wound up with mine?
i think the smell arround the tank would easily tell you if thats whats leaking.
Ed

 

[Richard Shelby]

Ed:

Just an update: the bladder inserts in both water tanks are still holding just fine. You lose some capacity, but so far, so good. My diesel tank is still original circa 1981, and I'm not gonna mess with it. My logic is that diesel is not as corrosive to aluminum as water. Now there's probably an inch of crud in the bottom which stops up the leaks. I would have the fuel "poished" like some recommend, but that might open a real can of worms. Water condensation in the fuel would possibly become a focal point for corrosion.....