# Thread Sealant for Water Piping



## tbaker (Dec 20, 2004)

Howdy All.

So I'm doing my own plumbing again for a remodel and an issue I've had previously was the threaded fittings connecting to PVC/CPVC piping.

Main spot is where I have the sink and toilet piping. I have been using glued piping all the way until a threaded dog ear 90 degree fitting. Then I would use a threaded nipple and install the threaded valve. I am leaking on all of them, most of the time. The threaded connection where I go from PVC to metal is typically the culprit, as I can only tighten so much until it explodes. 

Any suggestions on a particular brand of tape that would solve this issue? Or do I need to go to a pipe dope? (brand?) Or I have also heard of using both. Or if there are other options? (glued valves?)

Thanks in advance.


----------



## Hooked (Oct 15, 2004)

I've never had a problem like that using teflon tape when connecting PVC/CPVC to metal. However, have you tried finding the 90 degree PVC which is glued on one end and threaded on the other? I use those where feasible to connect the valve. 

How many wraps do you use with the tape?

Otherwise, you might try the pipe dope as it may seal better.


----------



## Stephanb (Aug 24, 2016)

I just use the blue glue for pvc with a little primer before. Work good for me, good luck


----------



## tbaker (Dec 20, 2004)

Sorry, I should have clarified. The fittings are PVC on one side, and metal threaded on the other. The leaks are typically on the metal to metal. 

I have been doing 2-3 wraps with the tape, but obviously that isn't enough.


----------



## Stephanb (Aug 24, 2016)

Make sure you wrap the Teflon the right way


----------



## rancher (Mar 27, 2013)

I have done lots of plumbing work around the ranch. What I do is use Teflon thread then coat the pipe threads with a product called Blue Magic Industrial Grade Pipe thread compound. I learned this trick from a master plumber years ago. He swore by it and I will to. Never had a leak. Here is link to product. Google for best price. Hope this helps.

https://www.jcwhitlam.com/Product/1/111/135# :cheers:


----------



## RB II (Feb 26, 2009)

Rector Seal 5 is the best thread compound for smaller diameter pipe, no matter if it is PVC or metal.

https://www.grainger.com/product/4Y...12525&ef_id=XNOUDQAAALcqRwFr:20190514013650:s


----------



## tbaker (Dec 20, 2004)

Thanks for the responses. To follow up I found some Oatey "Great White" thread sealant at Lowes and installed it with the Oatey Teflon tape. Seems to have done the trick.

I also installed a few temporary caps and only used the tape. One of them has a very slight leak that is almost like condensation. Going forward there will be dope on all permanent threaded fittings.


----------



## Titus Bass (Dec 26, 2008)

RB II said:


> Rector Seal 5 is the best thread compound for smaller diameter pipe, no matter if it is PVC or metal.
> 
> https://www.grainger.com/product/4Y...12525&ef_id=XNOUDQAAALcqRwFr:20190514013650:s


^^^^^^^^^^^^
This and no Teflon tape. Used this when I was in the carwash business. Best there is.


----------



## housewolf (Nov 24, 2014)

RB II said:


> Rector Seal 5 is the best thread compound for smaller diameter pipe, no matter if it is PVC or metal.
> 
> https://www.grainger.com/product/4Y...12525&ef_id=XNOUDQAAALcqRwFr:20190514013650:s


Thatâ€™s my go to for pipe dope (Iâ€™ve been a plumber 40+ years). *Be advised; it is not compatible with ABS.* Over time it will make the plastic soft and _it will crack_. It even says it on the can, but in very small print.

I think most of my guys like Megaloc now. Pipe dope & T-tape is for those that believe in luck. I donâ€™t think youâ€™ll ever have a threaded joint leak that used one or the other that could be repaired using both.


----------



## 4kids (Jun 18, 2004)

Also note that you should always use a female metal fitting with male PVC fitting. A male metal fitting will split a female PVC fitting before you can get it tight enough to stop a leak.


----------

