# Leak/crack Outlet Fitting Grey Water Tank



## AZarcher (Nov 15, 2008)

I have a 2007 21RS Outback that is very nice due to several modifications that I have made. Now I have a real tough problem. I recently spied a rapid drip off the under belly. I determined it was from the fitting between the tank outlet and the gate valve. I have removed a section of the under belly. The tank is a thin, brittle ABS plastic and is literally built into the trailer. There is a crack of about 3 inches in the bottom of the tank right next to the outlet fitting. A flange around the top of the tank is sandwiched between the sub floor and a metal strut on each side of the tank and the top of the I-beam on each end. Crap, the trailer is built around the tank! I searched the internet and this is probably the poorest quality tank available due to the brittle and thin ABS. If it is fixed with an epoxy intended for plastic it appears to me that it is very unlikely to hold up. The bottom of the tank is easily flexed. Also, these tanks, per internet talk, were not intended to hang without strap supports, which is the case here. I was amazed to find a site where the assessment of the tank was the same as mine. This guy changes tanks, using polypropylene which is virtually indestructible. He cuts the old tank out and uses a circle saw to cut around the vent pipe and drain pipe which are glued into the top of the tank. He uses a wood dowel inside the circle saw that goes into the inside of the pipe so the circle saw doesn't walk off track. The new tank must be customized so the openings on top exactly match up to the drain and vent pipes. He uses a bees wax coated foam donut on each opening that seals around the pipe when the tank is pushed up into place. This is like setting a toilet, except blindfolded. Those pipes are glued into the top of the pissy tank at the factory. I can see that they may very likely need to be extended down a few inches to insure they extend far enough through the openings of the new tank, another tough task. Impeccable measurements and/or a template may be needed to insure the top of the new tank and the openings line up perfectly. I can see that I can fabricate a support system so that straps can be installed to hold a new tank up in place. If I do this I plan to use a tank with an outlet on the end, drivers side, where I would put a gate valve. This valve would be just under the left side and outside the belly where it would be accessible. That means the black water would have its own gate valve separate from the new waste tank gate valve. May the Gods look with favor on the black water tank that it does not fail me.

Has anybody had experience with this kind of problem, maybe with the same rig or a similar rig? I am open to ideas. Tearing out internal infrastructure to do this job just does not seem to be an option in my opinion....proverbial rock and a hard place.


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## CamperAndy (Aug 26, 2004)

Vdub did a glue repair on his trailer tank a few years ago and reports it is still holding.

Vdub's tank repair


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## GlenninTexas (Aug 11, 2004)

Camper Andy is right. Several of us have used JB Weld to fix cracks. It works very well. Before investing a huge amount to replace the tank spend $6 -7 bucks and a little work.

Regards, Glenn


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## AZarcher (Nov 15, 2008)

GlenninTexas said:


> Camper Andy is right. Several of us have used JB Weld to fix cracks. It works very well. Before investing a huge amount to replace the tank spend $6 -7 bucks and a little work.
> 
> Regards, Glenn


I did the repair first and am waiting for it to cure...looks good. There is an exact polypropylene replacement tank that I found on Tweety in the event I have to take the replacement route in the future. I can do about anything, but working upside down under an RV is not a favorite. Thanks


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## BoaterDan (Jul 1, 2005)

I did a lot of research on repairing the tanks when my freshwater was dripping and found for the poly tanks the only thing really guaranteed to work consistently is "plastic welding". I found a kit online for around $30 if I remember. It's basically a mix between a glue gun and a soldering iron... the basic idea is melting new plastic material into the existing stuff. The one I bought came with some reinforcement mesh, so my repair is way stronger than the original.

Some people above have reported success with JB Weld, so it probably is fine. If it doesn't end up holding, the plastic "weld" definitely will.


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