I need some plumbing advice. I had to remove a 2′ section of a 4″ PVC soil stack. My plan was to use two PVC no-hub couplings (repair couplings). I primed the inside of the couplings and slid them onto the cut ends of the stack. I primed the cut ends of the stack, then primed the 2′ repair section of pipe. I put the new 2′ section of PVC in and applied cement to one end and slid the coupling into place with a twist. It seems like as I slide the coupling down it’s pushing out the cement and I cant get it to fuse. Is there a trick to this? I can also use the flexible rubber couplings, but figured that if somebody manufactures a no hub PVC coupling, there must be a way to do it. Any advice?
Also, if I do end up using the rubber couplings, the sign at Menards said that many municipal codes require the type with the full metal jacket, not just the two straps. The type with the full jacket also have an internal hub. Is there a trick to those as well?
Thanks for the help.
Steve
Replies
I would use
the rubber couplings. The ones I get do not have the rib inside, and they do have the Full Metal Jacket.
I can't see how you're going to prime and glue a couple of 4" pipes and simultaneously slide a repair coupling into place correctly. Too much chance of the cement grabbing before you're there....
Steve
PVC repair coupling are the proverbile bear to work with. It is a two person job on larger size pipe IMO.
If you already have them in place the trick to getting them to seal after they have been glued is a heat gun, Heat the coupling evenly with the heat gun untill it is to hot to touch, but not enough to soften the fitting. At that point the run a dopper full of cement around the end of the joint. The glue will suck into the joint, somewhat like soldering copper pie, and seal it up. Since you are on a vent stack, you should get a good enough seal to prevent any stink escaping the pipe.
The trick to the rubber repair couplings with the metal band is pretty simple. Take the whole metal band off the rubber boot. Slip the boot on one half of the joint and the roll the open side back over it (like pulling a sock off your foot by rolling the top down half way). Set your other piece of pipe on and roll the boot back across it. Reapply the band and tighten. I take a lot of cast iron pipe apart and put it back together and that is the only method that works consistantly.
The sign for Fernco type couplings was correct for most places. The two strap type repair couplings are only allowed outside the footing lines in most jurisdictions.
Dave Richeson's advice about using metal-jacketed neoprene couplings is your best bet.
BUT, in regard to the technique needed to use pvc repair couplings successfully:
The main trick is to scrape a nice bevel all around the outside edge of each pipe end. Without that bevel, the sharp corner of the cut edge scrapes the glue and softened plastic ahead of itself, leaving behind a surface that grabs aggressively and quickly.
The next trick is to generously coat the pipe with primer and glue for the full length of the coupling (not just the portion that will actually fill the socket of the fitting) on the piece that you first slide the coupling on. Fresh glue will act as a lubricant for a short time if you don't scrape it off with sharp pipe edges.
Another trick in to use only one repair coupling, if you can lean the pipe ends apart after gluing in the regular coupling.
Finally, cut the repair pipe just a little short (about 3/8") than needed so that the pipe ends don't touch, and make reference marks on the ends of the pipe so that you know how far to slide the repair coupling.
Have everything ready, work fast and wear neoprene-coated gloves for good grip.
Most important: have wife help so you have somebody to yell at when things get intense.
Yep
That is the way I have done repair couplings.
Only thing I might add is use enough glue to make it slick as snot. To much is not possible.
That is why I reccomend two people on large pipe. Quickness and the extra set of hands help.
The heat gun trick can be used as a follow on for any small leaks that you may have. Since he is doing a soil stack he may not even need that.
Plumbing Problem
Give up the glue, just use Misson or Fernco couplings and cut your piece approx. 1/4in in short, wiggle it together so you don't have any bulges at the joints, put the bands on and tighten it up, if it doesn't work you can do it over, not with the glue, luck.