Freshwater Tank Repair

[jimmoore13]

The fresh tank on my PUP has a small leak...near the top.
I'll flesh out the details in a moment.

The leak is a stress crack near the top of the tank. A "FlexSeal" product failed to plug the leak. I'm hoping to learn about the best product to seal or weld the crack. JB Weld comes to mind, but I'm seeking recommendations.

Details:

• I must always travel with a full tank, because we exclusively boondock--never have hookups, AND there is no potable water on site;
• It's a short drive to the site...about 15 miles....but 11+ miles of that is on torturous washboard gravel roads that shake your teeth out - thus the crack;
• I've recently reinforced the tank with a steel structural member supporting a plywood-backed rubber pad under the center of the main section of the tank;
• The tank is a stepped design. One side is shallow--to slide in over the top of the cable lift mechanism--and one side is deeper - to hang down lower and add capacity - designed to allow tank replacement without moving the roof-lift cable guide;
• The stress crack is high on the tank at the point where the step-down occurs;
• The leak is just a fast drip...one drop per second...and once the supply is used so the level is below the crack, the leak stops;
• I could, for example, use a Dremel to open the crack a bit to accept a bonding agent, but I don't want to do anything before I know what bonding agent is best suited to the task.

Of course I could simply replace the tank, but it seems as if it would be repairable...at least to survive a couple more years.

Questions:
1. What material is the tank made of?
2. What is the best bonding agent for that material?
3. Is that bonding agent at least a little bit flexible - which I believe will be vital to long-term success?

I'd appreciate your thoughts.
Thanks in advance.

[HangDiver]

I never had to do it but there's this: How to Repair Fresh Water Tank Cracks | www.trailerlife.com

Good luck

[4x4FF]

Depending on access and amount you want to spend you may want to try flex "tape" or even better would be trying a strip of eternabond. I would clean the surface thoroughly before hand as directed and press the tape on with a roller.

[Fireguy205]

JB Weld has a product called water weld, I have used it a few times for other things and it works great.

[4x4FF]

Maybe a combination of fixes. Use the jb weld then place a square of eternabond over it.

[rsdata]

Gorilla tape... find it at Home Depot...

once it sticks it is very difficult to get off even underwater...

[ttocsmi]

I tried numerous times to fix the crack in the fresh water tank of my old pop-up. My advice:

Find some place that does polyethylene (plastic) welding. Essentially a big soldering iron with w polyethylene 'wire' feeder. Once and done.

Nothing sticks to it; otherwise and you'll be wasting your time/money.

[jimmoore13]

So...

1. FlexSeal failed.

2. Permatex fiberglass-embedded plastic repair failed.

As some have suggested, nothing really sticks. The Permatex held water for about an hour, and then the leak found a path out and resumed at it's prior rate (about one drop per second).

I suspect that when I check the Permatex, it will come off the tank as easily as the FlexSeal...a putty knife and/or wood chisel to gently lift of the bonding agent. That's good news in that I could still get a weld repair done. Fortunately the crack is easy to get at from below - assuming a welder will put up with that.

If I have to remove the tank, I may as well replace it.

By the way, I did fabricate an additional tank support that works very well. Too little too late in this case, but when I repair or replace the tank I will reinstall this additional support.

Next time I'm under the rig, I'll take photos of the support.

Thanks for all the input.

P.S. Permatex warns that it's not for use on this kind of plastic, so not their fault. But some reported success, so I gave it a try.

[jimmoore13]

Originally Posted by jimmoore13

So...
<SNIP>>
If I have to remove the tank, I may as well replace it.
<<SNIP>>

Last night I wrote to Forest River Parts (Kathy Swope), and she got back to me with a part number and price.
$95 plus shipping for a new tank.

Before I pay the likely very high shipping cost for a part this large, I will see what a local dealer charges for the part.

I had visions of many hundreds of dollars, but for $95+, I've already wasted enough time on a broken piece of plastic.

[HangDiver]

After fabricating additional tank support(s), if it were me I'd probably go ahead and replace the tank. Piece of mind. Or is it Peace of mind?

Rich J.