How to stop PVC thread joints from leaking?

[Joerg]

It's an irrigation valve this time but same with garden faucets and stuff so it might be of interest to others here. I have a really hard time threading on PVC nipples, adapters, valves and whatnot without hearing that faint hiss when turning on the water. Then drip .... drip .... every ten seconds.

So far I've tried: Three layers of Teflon tape, Oatey Great White Pipe Joint Compound, Master Plumber TFE Paste. Nothing even comes close to the old hemp & paste method I grew up with, which never ever leaked. All this newfangled stuff always leaks. Grumble. Thing is, there comes a point where such a thread gets overtorqued and if I did that right now on our problem under the house I'd cause major grief because the contractors had joined all this stuff together without any pipe in between.

The old valve actually sat in there quite loosely and didn't leak. I could unscrew it by hand. They had used some really thick white gunk, not this runny "modern" stuff. What could it be? Any other options?

Regards, Joerg.

 

[B2CHR]

This stuff is what I have been using for years and seems to allways work for me...
http://www.rectorseal.com/index.php?site_id=1&product_id=213

 

[Sponsor]

 

[Joerg]

Thanks! Any idea which of the typical stores carry it? The web site just gives an order form where you need password and such. No problem, but that usually takes a while. If a local place carried it I could fix it before July-4

Someone else mentioned the thicker yello teflon tape for gas installations.

I probably have to whack it all apart again because those PVC unions I put in there won't turn. Almost as if they were glued.

Regards, Joerg.

 

[Redwood]

Any plumbing supply house should have it or the equivelent available.
Make sure that it is compatable with PVC.

 

[Joerg]

Just found out that ACE has it online so I can order it through a local ACE hardware store. Great! I just hope this stuff isn't as runny as all the other stuff. Says in the specs that it won't dry. Wish it would at least to some extent like the good old pipe dope.

And yes, in the description for Rector Seal it says PVC compliant.

Thanks, guys.

Regards, Joerg.

 

[Bob NH]

I use a PTFE-loaded dope that I got at HD. I put it on the female threads and then some Teflon tape on the male threads.

You might be able to take the union apart as follows:

1. Put a pipe wrench on the hub of the union opposite the nut of the union.

2. Put another pipe wrench on the nut of the union.

3. Using a steel hammer, and with someone applying moderate pull on both wrenches in the direction that will restrain the hub and unscrew the nut, pound sharply on the handle of the wrench on the nut (Avoid the other persons hand).

Ten to twenty whacks should start the union nut.

 

[Joerg]

Got to buy a wrench that fits that big union diameter. Mine are long enough but too stubby to reach over. The hammer trick won't work since this is in a location where I can only crawl to on my back (followed by a hacking cough from all the dust). Only very minor arm and wrist movements are possible. And it's all built with butting-up elbows and tees. If I break anything it'll be a nightmare. To add insult to injury they installed the manual shut-off valve into a brass T on the main line using a steel nipple. Oh man, that would never come off again. The "pros" who installed this should be .... well, lets' not go there.

Oh, and of course the manufacturer did not provide a hex pattern anywhere on the union, just a slight knurl pattern. Great. What were they thinking? Or rather, were they thinking at all?

Regards, Joerg.

 

[Bob NH]

Sometimes a strap wrench is good for working on large union nuts. It is not as good with the hammer process because it tends to absorb some of the shock which is the effect that will often break loose a tight nut.

 

[B2CHR]

Home Depot carries it and it's not runny.

 

[Joerg]

Thanks. Got to run to Home Depot anyhow to buy some more nipples, couplers and such in case I end up having to hacksaw it all out of there.

Bob, the strap wrench is a good idea. I didn't take it down there because the strap won't come off of mine. But since those things don't work on oil filters anyhow I just cut the retainer piece off and then I will be able to open it.

Regards, Joerg.

 

[Joerg]

Just one more question before I take it all apart: Someone said that very tiny leaks can plug themselves over time. If that is true how long would that normally take on joints done with teflon tape that leak maybe one drop every 15 seconds?

Regards, Joerg.

 

[Patrick88]

Just one more question before I take it all apart: Someone said that very tiny leaks can plug themselves over time. If that is true how long would that normally take on joints done with teflon tape that leak maybe one drop every 15 seconds?

Regards, Joerg.

I don't think anybody can say when. It just sort of happens when the Plumber shows up and the leak is gone.

 

[B2CHR]

In my 35 plus years in home construction and remolding I have found that once a leak all ways a leak and most of the time all ways a BIGGER leak!

 

[Joerg]

Oops, ok, then I'll redo that job with Rector Seal. Also found that since the new valve is in there is water hammer when that turns off and the next one turns on. Dang!

And here I thought it would be as Patrick said, pain goes away the minute you walk into the dentist's office.

Regards, Joerg.