Aluminum tanks, replace or repair?

[Ed Schenck]

Over the years we have seen much here on HOW about leaking aluminum water tanks. I am wondering if there are any new technologies that I might have missed. Pictured are the two water tanks from an H37C courtesy of Ron Pearson. He did "plastic". Some have inserted bladders while others have sealed the entire tank from the inside. As you can see they are oddly shaped, about forty-five gallons each.

You H37C owners know that these are tabbed in and the inner-liner laid over them. Removing them means some pretty long fiberglas cuts of the two salon seats. I have made nice cuts with my Roto-Zip but never anything that long. What is the best way for getting those tops off? And cutting them so they can be glassed back on?

Really appreciate your help. I know at least one is leaking. :cry:

 

[Richard Shelby]

Ed:

You may remember that I went witht he bladder option. I cut the fiberglass and the aluminum with a sabre saw and a metal cutting blade. As far a resealing, I screwed two boards top and bottom (see photos). That seemed to hold OK. The baldders have also worked well.

 

[Johnb]

Ed,

As the owner of an 1983 HC37 I have no doubt this same problem in my future. In trying to figure out what to do I think I would first like to know more about the leaks.

After performing an autopsy on the holding tank, subsequent to it's dismemberment for removal, it was obvious that there was no way it could have been patched in place. The entire weld along the bottom had corroded and split. Once I had gone to the trouble of getting it out there is no way I would have put the same thing back

On the other hand, I have had success with fixing pin hole leaks in tanks (one gasoline in an old car) that went on to give many years of service. If the basic material of the tank, including the seams and nipples/connections is still sound I would be tempted to try and seal it from the inside. I figure that this is so much easier than replacing the tank (and cheaper) that it is worth a try. If you mess up you hav'nt really lost anything. Also there is so little pressure from a few inches of water that pin hole leaks should be easy to seal.

I would start by cutting some good size access holes in the top, vacuuming out the dregs of water with a shop vac and getting a good look at the inside of the tank and try to ascertain where the leaks are and what the condition of the welds is and go from there.

For sure, if the tank is truly "knackered" I would probably go to plan B which would be a plastic replacement, as documented previously in this forum - I would not want to fight this problem endlessly.

John Brecher

 

[Johnb]

Richard,

Could you please tell us the make and ID of the bladder you used, like I say I have the feeling this same problem is in my future.

John Brecher

 

[Ed Schenck]

I do remember now. And smart because you only had to make those two short cuts. Add to that the ability to easily check and replace them. I like it. Did you get the same capacity with those tanks? Do you recall the brand and supplier?

Opening the tank as you did, does it let you reach every corner? If so then one could coat the entire interior with something? Of course then there is the problem of putting a leak proof top back on the tank.

 

[Richard Shelby]

It was a Plastimo, the 39 gal. if I remember correctly.

http://www.westmarine.com/1/1/7517-31-7gal-flexible-water-tank-41-x-45-x-45-from-plastimo.html

I had previously tried to epoxy coat the inside, but that fix lasted about one year
before the leaks came back. The biggest problem is the internal tank Baffles which have to be cut out. #%!!@&^* !!

 

[Inline Don]

Over the years we have seen much here on HOW about leaking aluminum water tanks. I am wondering if there are any new technologies that I might have missed. Pictured are the two water tanks from an H37C courtesy of Ron Pearson. He did "plastic". Some have inserted bladders while others have sealed the entire tank from the inside. As you can see they are oddly shaped, about forty-five gallons each.

You H37C owners know that these are tabbed in and the inner-liner laid over them. Removing them means some pretty long fiberglas cuts of the two salon seats. I have made nice cuts with my Roto-Zip but never anything that long. What is the best way for getting those tops off? And cutting them so they can be glassed back on?

Really appreciate your help. I know at least one is leaking. :cry:

I have a 37 gallon aluminum water tank on my S2 Sailboat which had a leak, than found almost a hundred small pit holes. Rather than replacing it I removed it and had it coated with a coating, potable water approved, which is sprayed on the beds of pickup trucks, boat decks, etc. I used Line-X cost me $250.00, guaranteed for over 10 years, and is about 3/16" thick. Aluminum must first be primed properly. It is very strong and durable. I have heard of it also being used on gasoline fuel tanks.

 

[Ed Schenck]

Oh that's right Richard, there are baffles in there. Don's coating from Line-X is appealing except for having to remove the tanks. I like the ten year warranty part of it. I can purchase Roncos for about the same price though. If only they had something shaped like that. Still learning.

 

[sandpiper10471]

HMP (Holland Marine Products) in Toronto will make up new poly tanks. Why not send them a detailed plans drawing and get a quote? We might find a whole bunch of people wanting to buy new tanks and thus get a prefered price!

 

[Ed Schenck]

Excellent idea Bill with one exception. First the tanks have to be removed. So I would have to make the decision to NOT repair in place or not use a bladder. Then both tanks would have to come out since they are not mirror images. But the idea joins the list. I may investigate the likely cost of welding up a couple of tanks.

 

[sandpiper10471]

You are of course right, Ed. The tops of the settees have to come off and the tanks lifted out. Then the tops have to be glassed back in. I am sure they add structural rigidity to the hull as well as contain the tanks, storage, pumps etc. I suppose if something like JB weld could be used on the welds, the top would still have to come off for access. Why is nothing easy on a boat except the silly smile on a close to perfect day? And isn't any day on the water close to perfect?