NO DOPE!!! Dope!


I was just replacing our dishwasher with a new one, and I noticed
something...
First off let me tell you in the past I have always swapped stuff like this
myself, but when we moved into this house we were just too busy and I didn't
have time to do everything. I let my wife hire a plumber to install the
dishwasher we brought from the old house and move her fancy toilets.
Anyway, I pulled the compression nut off the water supply line and it was
wrapped in pipe dope... over top of teflon tape... AND there was more pipe
dope under the tape. I stripped all that crap off the fitting with a wire
brush and installed it in the new dishwasher. Tape on the tapered pipe
thread into the machine, and nothing on the compression side from the supply
line. Amazingly it work just like it was designed.
Wadda dope!

Reply to
Bob La Londe
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I scoffed the first time I saw dope on top of tape (tapered pipe threads). Since then I've screwed together a lot of joints including quite a few with messed up threads that would only seal with the verboten combination of tape and dope. My most recent one was on the oil cooler of a stranded 60's vintage bus. The pipe fitting had been broken off flush and I could only get it out by slotting it with a die grinder. Laying on my back with sand blowing and oil dripping in my eyes while breathing bus exhaust (engine needed to run the compressor), I couldn't be faulted too much for dinging the female threads pretty badly. Especially since I'd driven to the middle of nowhere to work for free. I figured that the best I could do was seal the joint sufficiently to get the bus rolling while trailing a leak. But lots of tape and a little dope actually sealed the thing. Not even a drip.
Wayne
Reply to
wmbjkREMOVE
See! Wire brushes work MAGIC! Just make sure you throw them away after each use and buy new ones.
Reply to
Buerste
Never, ever, check up on work that you've paid to have done. It only leads to unhappiness.
This just reinforces what I always tell my wife about hiring workmen -- why should I pay good money to have them screw thing up, when I can screw them up myself for free?!?
Reply to
Tim Wescott
The thing is Teflon tape can actually prevent the nut of a compression, flare, or double flare from going on fair enough to cause the connection to seal properly.

Reply to
Bob La Londe
It can also stop a leak in the middle of the night, when there are no 24 hour plumbing supply places if you know how to do it.
Reply to
Michael A. Terrell
I think we are going to have to agree to disagree on this one. The only way I can see Teflon tape help on a bad compression or flare connection is if its overwrapped off of the thread and onto the mating surfaces to form a sort of jacked up gasket. We are going beyond shade tree on that one.
Reply to
Bob La Londe
I used it on an out of round compression fitting on a toilet shutoff valve. It filled the void, and stopped the leak until I replaced the toilet a year later. The 'plumber' had used too short of a tube and crimped it before the gland nut was tight enough. I'm not saying to use it every time, but sometimes it keeps you from being without running water while you get the right parts.
Reply to
Michael A. Terrell
God, I HATE compression fittings! Shark-Bites are TOOOOO cool!
Reply to
Buerste
I might be getting old, but I still prefer soldered copper fittings.
Reply to
Michael A. Terrell
Properly soldered fittings last forever.
Reply to
Bob La Londe
They can be dismantled and reused with no waste, too.
Reply to
Michael A. Terrell
You know its funny. I am lousy at sweating copper fittings. Just don't have the knack... or haven't done it enough more likely. One day I walked into my son's bedroom and sitting on his work bench was a copper tube sculpture all assembled with sweated fittings and tube. When I asked were he got it he said he made it in shop class. I looked it over carefully with a magnifying class and every joint had perfect wetting out. No gaps and no beads. Just beautiful fillets like you get when its done right. Talk about a proud dad. There is one thing he can definitely do better than me.

Reply to
Bob La Londe
One trick is to use metal polish instead of emery cloth to clean the pieces. The second is to use lots of liquid acid flux. The final trick is to use plenty of heat so it doesn't spend too long in the 'plastic' state and flows into the joint before all the flux burns away. I used to pre tin some critical parts and wipe off the excess solder with a rag before assembly. You don't want a 4" copper pipe with over 60 GPM to leak, inside a $25,000 TV transmitter. :(
Reply to
Michael A. Terrell

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