flynhi

My PVC sprinkler system has sprung a leak in a connection that is almost impossible to get to. To replace it I have to re-do a half dozen other fittings and dig a huge hole.

I'm trying to find a chemical that will fuse the PVC of the fitting to the PVC pipe to seal it. I've tried epoxy but it just peels off when the water pressure from the leak gets underneath it.

Any ideas?

Robert N

There is a special PVC cement. Give me a sec and I will get some more details.


Available at Home Depot for $7.87 (online). There are several brands.

Medium-bodied blue colored cement for PVC pipe and fittings. Up to 6 in. diameter. No primer is needed on non-pressure DWV where local codes permit. Recommended for all grades and types of PVC pipe and fittings, potable water and DWV. Very fast-setting cement formulated for wet conditions and/or quick pressurization and fast installation. Recommended application temperature 40 degree F to 100 deg. F. Meets ASTM D-2564.


[Modified by Robert N, 1:32 PM 10/2/2003]

mrvette

OK, here is the bitch...you have to make damn sure it's totally dry...blow the lines forever with air if you have to...but totally dry...you can cut the PVC lines and splice them with couplers from Home Despot with the same PVC cement...or you can just glop the cement over the spot and pray....

couplers are super cheap, and also pipe...and it's a rare system you can't fix with minimal problems....

total price I see is about 20 bux MAX.....assuming no communications breakdown....


OH...the solvent for PVC type compounds...including car interior vinyl is....

MEK....Methyl Ethel Keytone....

available in most paint departments....ten bux/quart....

GENE

Gator81

I suppose this is in the line between the supply and the valves, so it's under pressure all the time (for the irrigation season, anyway). If it's in the line downstream of the valve, it only leaks when the line's on, so who cares, right? Must be upstream or you wouldn't worry about it.

Me experience with PVC and irrigation lines is pretty deep. I've never seen a "patch" that was worth a damn. If it's easy to get to, you can get one of those repair kits that slides over the pipe, but it sounds like you're dealing with a leak at a fitting, up under something where "God and his angels can't see". (Thanks, Gene! :lolg: ]

My experience with cracked or split PVC fittings is that they just get worse. If you can get to it well enough to get it clean enough to gob a bunch of epoxy all the way around the fitting, then you can get to it well enough to cut it out and replace it properly. No fun. No fun a damtall. Sounds like you need 7 tools: a shovel and a six-pack! My condolences... been there, done that, more than once.

Might consider using black vinyl tubing (semi-flexible stuff) to manage the weird angles or whatever, as a replacement for the cut out section, if that's at all possible. Use stainless clamps, bury it up and forget about it. Good luck! :seeya

flynhi

Thanks to all for your input. I've used the Home Depot MEK glue for way too many sprinkler repairs. The problem is that to reglue the leak between the pipe and fitting using the MEK, I have to re-do a half dozen other fittings.
So I was hoping to find something that would fuse or melt to PVC to close the gap that is leaking.

Since it's on the upstream side of the valve, it leaks all the time.


[Modified by flynhi, 4:48 PM 10/2/2003]

mrvette

flyn, you got to drain all the water, and make damn sure the lines/leaks area in the cracks are DRY...then you can finally run in some MEK and glue to redo the things....OR cut and resplice as necessary....

MEK is the solvent, and can help you in cleaning, and rejoining...and will act as a glue in desperation...but nothing is a effective as the glue itself...you may want to try that purple primer also..but MEK is the primary component...

GENE

Robert N

Stupid pet trick - PVC is plastic. It melts. I have fixed many a broken toy and other assorted plastic stuff using a soldering iron and an old tip to either melt the plastic to seal or "weld" a small piece of plastic to patch the area.

Worth a shot?

flynhi

Robert N - Good idea. Does PVC burn? Could I use a hand held torch?

Robert N

I don't think it will burn as in "going up in flames" but a torch may be too hot, but more likely won't direct the heat to the spot needed. Soldering copper pipes requires you to heat the pipe and touch the solder to it. That will cause the solder to flow and seal. PVC will melt so the idea is actualy get the pipe soft enough to melt the edges of the holes together without collapsing it altogether. Best advice would be to get a short piece of pipe from the local Home Depot/Lowes for a buck or 2 an experiement like anything else.