flex and seal plumbing repair

Hi Don,
I once cracked my black tank pipe behind the gate valve while backing down a twisting, vegetation overgrown driveway. I hit the dump pipe on a stump sticking out.

I emptied the tank, parked it so the drain was high and got under there and very thoroughly cleaned the area of all dirt etc, especially around the crack in the pipe and fitting.

I used Blueskin, which is a building construction waterproofing membrane, peel and stick similar in properties to Eternabond. I used a heat gun to make sure everything was toasty warm after putting it on.

After covering the offending areas it never leaked again.

I have a leak on my grey water outlet pipe. It rubs on a bolt near the wheel axels - poor design, surprising I know. Anyway, I had some flex tape from a pool leak that I tried flex tape. Flex tape did not fix either leak. All over youtube people fix leaks with flex tape. I found it doesn't work.

Eternabond won't hold on waste tanks.

No, but I have used cheapo Homedepot fiberglass "resin" and some loose fibers. Just soak the fiberglass sheet or fibers in the epoxy and smear/wrap/slather on the cleaned and sanded crack. Marine epoxy would be better if you think the pipe might move or wiggle as Marine is more flexible.

Hint: while a simple, loose cotton face drape might protect you from the world's most deadly virus ever, i would use a canister respirator mask when working with epoxy - also available at HD.

Fiberglass is not ideal for sticking to plastic. Using a better, real epoxy, resin would be better, but more expensive.
All you are doing is stopping water leaking from a few inches of pressure, so my repairs have worked.
Also, JB weld for plastic might be enough too.

VHB tape should work on the pipe, but not at a junction. VHB tape does not like corners or ridges, just flat surfaces such as a pipe.

jdc1 wrote:
Eternabond won't hold on waste tanks.

It is not the tank--it is the pvc pipe{s}. (I hope that is correct--dealing with third hand information.)

Thanks for the replies so far.

Don...in the past I've used black abs cement to fix damaged sewer pipes. You need to clean pipe with abs cleaner first, then add a thin coat of ABS black cement. While still wet, add a proper sized piece of fiberglass screen (same as screen in RV door) into the wet cement. Let dry, then add another thin layer over the screen, let dry. Over night dry time may be needed for a large crack. Three thin coats, until you can no longer see any screen should do it. I've never had a failure, using this method.

Jerry

I have given up trying to get folks here to ignore junk huckstered on TV like the flex products and fix it correctly the first time..

They have nothing to loose other than the resulting mess when it eventually fails.

Tell them to try it and see if it works.

The BEST way though is to cut out and splice in new material.

Takes more time and effort to fix it correctly the first time but often you will be rewarded with never having to revisit the problem ever again.

They have ABS, ABS is by far one of the easiest things to fix and the fix is permanent. ABS like PVC is solvent welded and in most cases the same solvent is used on both provided the label states it is rated for both.

ABS unlike PVC can be solvent welded without use of a primer.

The most difficult part will be gaining enough access to the broken spot to cut the pipe off. But heck if you can get into it with a tape product like flex tape or enternabond you should be able to cut the offending spot out.

Small grinder with abrasive cut off blade will easily cut ABS as well as a hacksaw. Hint, small air powered "die grinders" equipped with a cutoff wheel are very small and compact and work very well in tight spaces.

All is needed is a piece of ABS pipe long enough to replace the section cut out and two ABS couplers. ABS can be flexed some to aid getting the ABS couplers on.

Alternate method to solvent welding is using two rubber couplers (often referred to brand name of Fernco)and a piece of ABS pipe. The rubber couplers simply slide over the pipe and are tightened via stainless band clamps (can use screw driver or a socket wrench). Both fixes in this case will be permanent and should never be an issue again. Rubber couplers may have a slight advantage if the original issue comes from pipe being too stiff by adding a flexible joint.

Anything else than cutting out and replacing is nothing more than a temporary patch or bandaid.

pianotuna wrote:
Hi all,

Has any one used flex and seal wrap (tape) on waste water plumbing on their RV? Asking for a friend who has a plumbing problem.

Would eterna bond work?

Hi piano,

See this thread where a similar question was asked. I have much more to add if needed, http://forums.trailerlife.com/index.cfm/fuseaction/thread/tid/30301229/gotomsg/30301329.cfm#30301329

In these plumbing leaks situations, it really helps to know more about the leak, and ideally, see some pics of the leak area. I know you are getting this 3rd hand, but get some info from your buddy and we can help better.

If there is a cracked tank, cracked pipe, cracked tank fittings, this all comes back to, where is the crack and what caused the crack? Knowing some about the first topic helps greatly on backing into what caused the crack. Then comes how to make a band aide to get by if needed to get you home, followed by a permanent repair that removed the temporary patch and does a permanent fix.

This much I can say, Eternabond is not a long term repair on a RV tank/plumbing system in "most" cases. I have used a lot of Eternabond, and it is really good stuff when applied right, just this is not the right application. Ebond has no mechanical strength to reinforce the leaking joint to not continue ripping or leaking long term.

We really need to see and know more about the leak to help guide you better. Putting flex seal etc. on as a band aide may contaminate the area making a permanent fix harder to grind out, scrape off the goop put on wrong.

ABS plastic that most RV waste systems uses is very repairable, permanently. From small cracks, to mega missing parts ripped out of the tank, using an ABS solvent weld method, ABS plastic sheet filler, ABS pipe, fiberglass reinforcing mesh and, addressing the original reason why the crack/leak happened in the first place.

Hope this helps

John

Since the sewer line is not under pressure you may want to Google for "Insta-Clamp Plumbing Repair Clamp"

ajriding wrote:
No, but I have used cheapo Homedepot fiberglass "resin" and some loose fibers. Just soak the fiberglass sheet or fibers in the epoxy and smear/wrap/slather on the cleaned and sanded crack. Marine epoxy would be better if you think the pipe might move or wiggle as Marine is more flexible.

Did this years ago on a cracked gray water pipe. Had some marine epoxy from boat work:
- Cleaned the pipe.
- Scuffed the area with sandpaper.
- Wrapped with fiberglass all the way around the pipe and then wetted out with epoxy.

7yrs later when we sold the trailer it was still holding. Another 6yrs on, I know the current owner and have seen the trailer this past summer...the repair is still holding.

PS: I probably wouldn't bother with marine epoxy if I was buying material. It's very expensive. Cheaper vinyl ester resin should work just fine.