Fresh water tank cracked. Advice?

[Bill Sprague]

It appears my fresh water tank is cracked.  Water is dripping from the bottom of the plywood support and the fittings are dry.  So, I suspect a crack.

Any advice or experience with this?

Thanks.

[Gerald Farris]

Bill,
I have worked on two different Beavers for a leak at the fresh water tank, and both of the leaks were caused by cracked fittings where they were spun welded to the tank. If you do actually have a cracked tank, any good plastic fabricating shop can repair the tank.

The supply fitting on my 93 Patriot cracked at the tank, so I had a plastic fabricator plastic weld a one inch thick boss onto the tank and thread it to replace the cracked fitting.

Gerald

[Bill Sprague]

Bill,
I have worked on two different Beavers for a leak at the fresh water tank, and both of the leaks were caused by cracked fittings where they were spun welded to the tank. If you do actually have a cracked tank, any good plastic fabricating shop can repair the tank.

The supply fitting on my 93 Patriot cracked at the tank, so I had a plastic fabricator plastic weld a one inch thick boss onto the tank and thread it to replace the cracked fitting.

Gerald

Thanks Gerald.  So far, it does not appear to be leaking at a fitting.  Based on where the leak is, I think the tank actually cracked.

Plan A is to see if I can slide the plywood out that is under the tank and look.  I think I might be able to do that with the tank empty.  Temporarily I going to route the suction line from the pump into a 5 gallon can or bucket, depending on what they have at the local Ace Hardware.  

Plan B is to get out the motorhomer's best tool (checkbook) and go to Bend.  

[Dick Simonis]

For a quicky repair, if the leak is obvious and accessable is to slap on a strip of eternabond.  That stuff is amazing in what it will seal.

[Bill Sprague]

For a quicky repair, if the leak is obvious and accessable is to slap on a strip of eternabond.  That stuff is amazing in what it will seal.

I would do that if I could quickly get to where I think the leak is.  I think it is going to be a bigger than average job.

[barbhalsell]

I have seen this rocommended a lot on different RV forums.
http://www.plasti-mend.com/

[Bill Sprague]

I have seen this rocommended a lot on different RV forums.
http://www.plasti-mend.com/

Thank you for the lead.  But, I think the tank is polyethylene and Plasti-Mend may not work.  

[Dick Simonis]

Bill,

It will be interesting to hear what it take to drop the tank, as it may be informative to all of us.  I had wondered about that myself, as access to the fitting on top should be......well interesting.

I'm guessing the tank location and mounting is similiar on most models.

As a side note, I've been successful in doing field repairs on poly tanks with a soldering iron.

[Bill Sprague]

Update:

I drained the tank and let the bay dry out for 36 hours.  Then I filled the tank about 2/3 full.  I waited and watched for the leak to reapperar and got nothing.  Then I drove for three hours and still no detectable leak.  

There are three visible and almost accessible fittings at the bottom.  One is for the outlet to the pump, one is for the Aladdin sensor and one for the electrically operated drain valve.  All are dry.  

There are holes at the top of the tank.  They are not accessible.  One is for filling and the other is the overflow/vent.  It didn't leak while I filled it, so the inlet is not the problem.

That leaves two choices for leaks.  Either the tank is cracked or the overflow/vent is leaking.  Tank cracking is rare.

I have long had the habit of keeping my water tank full with the notion that, should I discover an amazing place to dry camp, I would be ready.  I think what happened here is that the cold water in the full tank expanded as we drove to and camped in a warmer area.  It expanded so slowly that there was always a little water at the overflow/vent that should have gone overboard.  If there is a loose clamp or fitting there, it could slowly seep.  Then it might run down the wall of the tank and collect on the plywood under the tank and then drip on my fly fishing gear stored below the tank.  

The inexpensive, and perhaps smarter, solution here is to carry 50, not 100,  gallons of water.  Dropping the tank to look for a way to fix the probable seep at the overflow/vent would be difficult.  

From this day forward, my tank will only be full on my way to Quartzsite or the upcoming Mt. Rainier rallies!  

I'm very happy that I didn't pay someone by the hour to look for this leak!