tryinToGetBy
New Member
[Apologies in advance for the long story]
I'm trying to fix a leaking water supply line. Difficulty level: oddball-sized poly tubing (hose), i.d. 1.195" (mfgr i.d. specs for 1" and 1-1/4" poly tubing are 1.049" and 1.38" respectively). So if I had to guess, 1-1/8" poly tubing (with a fairly thin wall). The leak occurred at an existing splice between 1-1/4 poly and the oddball stuff. AFAICT, barb fittings for 1-1/8" poly tubing don't exist (according to local plumbing supply stores, big-box hardware stores, Amazon, Ebay, etc.: there are marine barb fittings claiming 1-1/8" barb sizing, but I've bought 2 different kinds of these, and the barbs are the same o.d. as the 1" barb fittings from the big-box stores: absurdly too small. And now isn't the right time to completely replace the many hundred feet of oddball line involved.
The only thing I've found that comes close to working is a "Homewerks Schedule 40 1 in. MPT X 1 in. D Compression PVC Male Adapter" fitting. I sanded down a copper sweat coupling to fit inside the oddball tubing to prevent it from collapsing when the compression fitting is tightened around it.
Splice version 1: comprised of this compression fitting, a PVC union, 1" PVC nipple, 1-1/4" MPT to 1-1/4" barb fitting, 1-1/4" poly tubing to 1-1/4" barb coupler connecting to the existing 1-1/4" poly tubing, plus adapters as required. During installation I accidentally cut the 1-1/4" poly tubing part of the splice about 7/16" too short. I went ahead and installed it all anyway but in hindsight this led to unanticipated problems: 1) the oddball sized tubing was not fully inserted into the compression fitting and after 2-3 weeks (I left it in the open trench unburied to monitor for leaks) the compression fitting started to leak a little, 2) the two poly tubing lines joined by the splice are not perfectly in-line, there's maybe a 5 degree angle, so over time the tubing entering the compression fitting could be seen more clearly to be entering at an angle. After 2 weeks the compression fitting was starting to leak, so I took the "not recommended" step of carefully tightening it with a pair of pipe wrenches. This only helped a little (and only temporarily, see below).
So anyway, 2 days ago I replaced the leaking version 1 splice with version 2: mostly the same configuration (w/all new parts), except I omitted the PVC nipple in lieu of a longer segment of 1-1/4" poly tubing. I cut this tubing exactly the right length this time, and I used the natural curve of that tubing to aim the compression fitting to be in line with the approach angle of the oddball tubing, so now the latter is entering the compression fitting dead straight (and is seated to full depth). And notably, when I removed my "Version 1" splice, its compression fitting outer screw shell (previously tightened with pipe wrenches as noted above) was completely loose. My suspicion is that while the old splice was in service unsupported, the 5 degree curve combined with water-slug inertial action (due to changes in water flow) caused the assembly to move around, causing the hand-tightened threads to work loose.
Re: version 2: after installing it, I placed a heavy stone up against the outside of the slight curve in the splice's poly tubing, in an attempt to limit motion due to changes in water flow, and keep the compression fitting in line with the tubing going into it (photo attached), and added another stone on top capture the tubing against the first stone. So far, in 1+ day of service, no leak is apparent.
To my questions:
Q1 should I spot-glue the threads of the compression fitting (which hold its rubber seal in place) to prevent it from possibly unscrewing during hopefully years of service. Similarly the PVC union adjacent to it also has threads that hold its joint together, but aren't waterproof threads either, just mechanical, which if they unscrewed would cause the underlying joint to fail. If so, what glue would you recommend (now that these threads are presently as hand-tight as I can make them, I'm not inclined to unscrew them at this point, just put on a dab of glue to fix them in place)?
Q2: I'm thinking it wouldn't hurt to wrap all of these joints with some appropriate tape just to keep the dirt out. Maybe silicone self-stick wrap, or ?
Q3: other suggestions?
Thanks in advance!
I'm trying to fix a leaking water supply line. Difficulty level: oddball-sized poly tubing (hose), i.d. 1.195" (mfgr i.d. specs for 1" and 1-1/4" poly tubing are 1.049" and 1.38" respectively). So if I had to guess, 1-1/8" poly tubing (with a fairly thin wall). The leak occurred at an existing splice between 1-1/4 poly and the oddball stuff. AFAICT, barb fittings for 1-1/8" poly tubing don't exist (according to local plumbing supply stores, big-box hardware stores, Amazon, Ebay, etc.: there are marine barb fittings claiming 1-1/8" barb sizing, but I've bought 2 different kinds of these, and the barbs are the same o.d. as the 1" barb fittings from the big-box stores: absurdly too small. And now isn't the right time to completely replace the many hundred feet of oddball line involved.
The only thing I've found that comes close to working is a "Homewerks Schedule 40 1 in. MPT X 1 in. D Compression PVC Male Adapter" fitting. I sanded down a copper sweat coupling to fit inside the oddball tubing to prevent it from collapsing when the compression fitting is tightened around it.
Splice version 1: comprised of this compression fitting, a PVC union, 1" PVC nipple, 1-1/4" MPT to 1-1/4" barb fitting, 1-1/4" poly tubing to 1-1/4" barb coupler connecting to the existing 1-1/4" poly tubing, plus adapters as required. During installation I accidentally cut the 1-1/4" poly tubing part of the splice about 7/16" too short. I went ahead and installed it all anyway but in hindsight this led to unanticipated problems: 1) the oddball sized tubing was not fully inserted into the compression fitting and after 2-3 weeks (I left it in the open trench unburied to monitor for leaks) the compression fitting started to leak a little, 2) the two poly tubing lines joined by the splice are not perfectly in-line, there's maybe a 5 degree angle, so over time the tubing entering the compression fitting could be seen more clearly to be entering at an angle. After 2 weeks the compression fitting was starting to leak, so I took the "not recommended" step of carefully tightening it with a pair of pipe wrenches. This only helped a little (and only temporarily, see below).
So anyway, 2 days ago I replaced the leaking version 1 splice with version 2: mostly the same configuration (w/all new parts), except I omitted the PVC nipple in lieu of a longer segment of 1-1/4" poly tubing. I cut this tubing exactly the right length this time, and I used the natural curve of that tubing to aim the compression fitting to be in line with the approach angle of the oddball tubing, so now the latter is entering the compression fitting dead straight (and is seated to full depth). And notably, when I removed my "Version 1" splice, its compression fitting outer screw shell (previously tightened with pipe wrenches as noted above) was completely loose. My suspicion is that while the old splice was in service unsupported, the 5 degree curve combined with water-slug inertial action (due to changes in water flow) caused the assembly to move around, causing the hand-tightened threads to work loose.
Re: version 2: after installing it, I placed a heavy stone up against the outside of the slight curve in the splice's poly tubing, in an attempt to limit motion due to changes in water flow, and keep the compression fitting in line with the tubing going into it (photo attached), and added another stone on top capture the tubing against the first stone. So far, in 1+ day of service, no leak is apparent.
To my questions:
Q1 should I spot-glue the threads of the compression fitting (which hold its rubber seal in place) to prevent it from possibly unscrewing during hopefully years of service. Similarly the PVC union adjacent to it also has threads that hold its joint together, but aren't waterproof threads either, just mechanical, which if they unscrewed would cause the underlying joint to fail. If so, what glue would you recommend (now that these threads are presently as hand-tight as I can make them, I'm not inclined to unscrew them at this point, just put on a dab of glue to fix them in place)?
Q2: I'm thinking it wouldn't hurt to wrap all of these joints with some appropriate tape just to keep the dirt out. Maybe silicone self-stick wrap, or ?
Q3: other suggestions?
Thanks in advance!
