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Topic: Black Water Tank crack at connection - need repair options (Read 899 times) previous topic - next topic

Black Water Tank crack at connection - need repair options

We have a crack in the discharge pipe from the black water connection.  The bad thing is that the crack grows into (or maybe started at) the tank.  See the pictures at the following link.

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Any repair options would be much appreciated.

Re: Black Water Tank crack at connection - need repair options

Reply #1 –
Welcome to ForeForums.  I wish your first question was about something easy like interior light bulbs. 

Based on looking at the photos, I really think you need to replace the entire discharge pipe and any valves.  I didn't see what year your coach is, but from the looks of the sewer pipes it is pre-1995.  And, as long as you are going to this effort (or paying someone to do it) you might as well do it once, do it right and then forget about it.

If the crack starts in the tank it might be able to be repaired.  I would hope so as this would be a whole lot easier than taking out the old black tank and putting in a new one.  Others with more experience in working with plastics will most likely suggest some options.

Good luck.  I hope this is the worst repair you ever have to face.
George Stoltz.  Retired from full-time living in a great Foretravel and now are back to living in a traditional sticks and bricks in Florida.

Re: Black Water Tank crack at connection - need repair options

Reply #2 –
Some reading:

http://en.wikipedia.org/wiki/Plastic_welding

I am not always known for doing things the best way.  Having said that, I would probably drill a series of small holes and bind the parts together snugly with wire, then cover the whole area with Shoe Goo.

oldMattB
Matt B
1998 u-320

Re: Black Water Tank crack at connection - need repair options

Reply #3 –
Been there-with my previuos GV. I had a crack and took the pipe out (after emptying the tank of course), clean the whole area up and took a knife blade to the inside of crack to remove any crud etc. Once you have a clean area get some of the vinyl bumper repair stuff filler (from a body shop) and fill the crack with it and shaping to suit. Re-assemble and use a good stainless gear clamp to cinch it all back again. The real way to fix is to have it abs welded, but the way I mentioned will suffice if it is cleaned properly. As an extra when you are putting the pipe back in, put a bit of pipe cement on it where it sits next to the repair. There is a repair kit available in RV stores supposedly to fix cracks on Black tanks but I found it useless and peels off easily and it is expensive too. I had a large crack on both tanks repaired the way I have said and never a drop again.
Good luck.
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Black Water Tank crack at connection - need repair options

Reply #4 –
We had a black water tank on our Southwind crack. It not only got worse but leaked and got us kicked out of a parking lot while shopping (gross). I tried the RV shop tank repair stuff with no success and even bought a hot air plastic welder but no success with it either. I finally cleaned the outside and the inside where the pipe goes in with TSP and lacquer thinner, sanded it, painted on a coat of epoxy resin (System 3 as I remember) and then cut Fiberglas cloth to fit the area extending 8 inches or so from the crack including under the tank. Built up several layers all around the tank discharge in an hour or so. I even put one layer inside the tank where the pipe goes in. Installed a new pipe with blue silicon as a sealer along with a new clamp and it has been fine for about 8 years or so. Still have the Southwind and no leaks so far. This area where the pipe goes in seems to flex a lot and probably the reason for a lot of failures here. Fitting a new pipe and valves is super easy and inexpensive. Just a tape measure, hacksaw, sandpaper and ABS glue. Don't think I would reuse the old one.
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Black Water Tank crack at connection - need repair options

Reply #5 –
 So someone else has had no luck with the RV repair kit like me that is why I used the Vinyl bumper filler. It is great and actually the repair was stronger than the original material.
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Black Water Tank crack at connection - need repair options

Reply #6 –
Very helpful tips.  Thanks very much!!  Sounds like you saved us a lot of trouble!