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Teflon tape on compression fittings?

44281 Views 39 Replies 17 Participants Last post by  madmax718
New angle stops on copper pipe in a remodel. Compression fittings. I've never used teflon tape for them; every once in a while after putting the water back on I have to tighten up; maybe once I've had to take a fitting off and redo it.

A friend says I'm nuts - he uses Teflon tape every time. Any opinions?
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I would not, unless they are stainless. generally those only need to be snug, not torqued.
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Plumbers paste only. If someone strangled the olive then i would just cut the olive out and put a new one on. Never seen anyone use PTFE tape on them.
I would never use tape on any kind of compression fitting (that I've ever worked with). The threads on the compression serve to compress the mating parts, not to seal the joint. I feel like adding tape can keep the threads from tightening to their full potential and/or get between mating parts.
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You are probably over tightening them. The threads don't seal the ferrule does, tape or dope is pointless. If anything a little grease wouldn't hurt.
Yes, usually. In one development we're often replacing 40-year old angle stops because the existing are frozen open. We strongly prefer not to change anything in the walls - we pay cash money for a couple of hours of building water shutdown, to replace a dozen angle stops and a couple shower valves, and we have to hustle. Sometimes the old fixture was cranked on and the olive is mashed into the copper. Even if we can get the old olive off without making things worse the new one doesn't always seat very well. Sometimes the old olive stays.
You are probably over tightening them. The threads don't seal the ferrule does, tape or dope is pointless. If anything a little grease wouldn't hurt.
I've had several plumbers tell me they use paste on compression threads more like a thread lubricant so it's easier to tighten and loosen. Kind of the opposite of locktite.
Yea. My opinion is he's the one that's nuts and does not understand how they work.

That's like wearing suspenders to hold your pants up AND adding a belt without the buckle. :laughing:
A friend says I'm nuts - he uses Teflon tape every time. Any opinions?
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That happens pretty often when a lubricant ain't used. People struggle to tell how tight them have the olive then over tighten/strangle it. I use plumbers paste for 2 reasons. One it lubricates the surfaces and it fills voids in the surfaces. PTFE tape can do the same thing as the Teflon helps the threads slip better but it pulls it self from surfaces that touch tight. Paste stays put much better.
CarpenterSFO said:
Yes, usually. In one development we're often replacing 40-year old angle stops because the existing are frozen open. We strongly prefer not to change anything in the walls - we pay cash money for a couple of hours of building water shutdown, to replace a dozen angle stops and a couple shower valves, and we have to hustle. Sometimes the old fixture was cranked on and the olive is mashed into the copper. Even if we can get the old olive off without making things worse the new one doesn't always seat very well. Sometimes the old olive stays.
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I'm waiting for the building folks to drain the water out of the 5 stories above us so we can get started. In order to shut off the water in any unit they have to go into a tenant's office space on the first floor, remove ceiling tiles, open some valves, and drain the 11-floor plumbing stack for 3 or 4 condos on every floor. Major PITA to get some simple work done. Scheduled weeks in advance.
Screw that go to a welding shop, get some dry ice and freeze the line. Cut the pipe and propress on a new shutoff, just leave the old pos on there.
I'm waiting for the building folks to drain the water out of the 5 stories above us so we can get started. In order to shut off the water in any unit they have to go into a tenant's office space on the first floor, remove ceiling tiles, open some valves, and drain the 11-floor plumbing stack for 3 or 4 condos on every floor. Major PITA to get some simple work done. Scheduled weeks in advance.
Have you actually done that before or are you kidding?
Inner10 said:
Screw that go to a welding shop, get some dry ice and freeze the line. Cut the pipe and propress on a new shutoff, just leave the old pos on there.
It's an idea.... Some of the 11 angle stops are right on tees running up the full height of the building. It would be the end of my business here.

Maybe I'll try it in a different situation sometime. No danger of breaking a line?
Screw that go to a welding shop, get some dry ice and freeze the line. Cut the pipe and propress on a new shutoff, just leave the old pos on there.
A drop of oil on the threads to keep the nut from squealing when you tighten it is all I've ever used.
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The ones I was thinking about are all done now anyway. No teflon tape, water's back on, no leaks. Spent a couple minutes putting an ice-maker box in the wall. Seems to me refrigerators used to have a recess around the bottom foot maybe. New ones don't, and the icemaker angle stop 2 1/2 inches out of the wall doesn't work any more.
It does work. I have used pipe freeze kits a few times in the past. Sure gets worrying when you start heating the pipe up lol.
dielectricunion said:
Have you actually done that before or are you kidding?
Yes dry ice does work ,that's what we use when replacing a water main in a finished area .
Screw that go to a welding shop, get some dry ice and freeze the line. Cut the pipe and propress on a new shutoff, just leave the old pos on there.
Never, I just watched in amazement as a plumber did it.
Have you actually done that before or are you kidding?
We always subbed out the pipe freezing to a company that specialized in it, it put the burden of liability on them instead of us.
Never, I just watched in amazement as a plumber did it.
That's pretty crazy stuff. Never seen it done but it seems like a smart way to cut off supply when you have no better options.
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