Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

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kcham
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Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Mon Dec 04, 2017 12:33 am

Or a combination of those?

I have not seen people use hemp for the past decade or more and I wondered why, wasn't that perfect at the time being? What changed and what do you prefer?


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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by Shannon » Mon Dec 04, 2017 7:35 am

Never have used Hemp so I could not tell you.
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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Mon Dec 04, 2017 10:09 am

How many warps of PTFE do you recommend, I tried up to 8, but it feels loose even for a shut-off valve, what measure should I follow to know that it is not loose or overdone, should I look for a decent pressure on the second screw in, when do you start using a wrench because you cannot continue by hand?

Also, some people say yellow PTFE is better, even for water supplies, how true is that or should I just buy whichever blue PTFE I find?

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by A. Spruce » Mon Dec 04, 2017 11:42 am

Teflon tape is neither a thread sealer nor a thread locker, its primary function is to make turning the nut easier so that you can get it tighter, thereby creating a leak free joint. Its ability to fill voids in threads is extremely minimal, for that you use pipe dope, the paste stuff.

I've only ever used white teflon and never had issues
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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Mon Dec 04, 2017 3:33 pm

Ok, PTFE will be. One more question, how tight should I screw in the shut-off valves I am planning to install?

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by A. Spruce » Mon Dec 04, 2017 3:58 pm

It only needs to be tight enough not to leak, for some things that's slightly more than finger tight, for others it takes several large men and a few small children to get it tight enough. It kind of depends on the type of materials involved, age, and cleanliness of surfaces. I would recommend that you get it good and snug, then test, if it's leaking snug it a bit more, if it's not, then monitor it for a day or two to be sure and you'll be good to go.
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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Mon Dec 04, 2017 4:02 pm

well it is T-fitting into two valves, I will try my options, I will also need to care for the T to be in horizontal position and the valves (which are L type) to be in straight position, this is what bothered me. All parts are nickel.

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by Shannon » Mon Dec 04, 2017 7:17 pm

A. Spruce wrote:
Mon Dec 04, 2017 11:42 am
Teflon tape is neither a thread sealer nor a thread locker, its primary function is to make turning the nut easier so that you can get it tighter, thereby creating a leak free joint. Its ability to fill voids in threads is extremely minimal, for that you use pipe dope, the paste stuff.

I've only ever used white teflon and never had issues
I think I would have to argue a point here :D ,yes Plumbers tape does help lube the threads and allow you to turn fittings together further and it also acts as kind of an anti seize material so those fittings will come apart easier down the road. But It also fills the voids between the two fittings (male & female) and stops moisture or even air flow through the threads. Pipe dope will do the same thing as well. I have never seen the two products used on the same joints though, its one or the other.
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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Mon Dec 04, 2017 7:54 pm

I have screwed everything up, that was the most crazy thing. First I was rolling PTFE for 9 minutes, because it was like there is nothing in between the joints, second, just like I said, it was either too loose or too tight, I could not get the positions right, so I was doing screw in screw out screw in screw out until I got them in palce.

Did I do anything wrong? I put less PTFE on some of the other valve thread joints, but I am concerned with the whole screw in screw out.

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by DanM » Mon Dec 04, 2017 8:06 pm

If something is still leaky with the teflon tape, or you're worried about it, just remove the tape entirely and use Pipe Joint Compound like Spruce mentioned. It's like $6-7 bucks for a small can of it. It lubricates the threads and seals them up tight. Put it on the male end, finger tighten as much as you can, then do at least 3 full 360 degree rotations with a wrench to tighten the fitting and get it into the position you want. Never loosen the fitting to get it into position, just do the 3 rotations and keep cranking until it's in position. To tighten it properly you may need a longer wrench and/or one that grips better. Longer handle = more torque = easier for you to tighten it properly.

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Mon Dec 04, 2017 8:18 pm

Won't I just break it that way, 3 full 360 turns?

It does leak, I put around 25 rounds where it leaks, pretty sure over 100 rounds where it does not. I am not even exaggerating. About the joint compound, wouldn't that just glue them forever?

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by DanM » Mon Dec 04, 2017 8:33 pm

It won't break the brass fittings. NPT fittings need to be cranked pretty damn tight sometimes (hence spruces comment about requiring a small army of large men and a few children from time to time). If your joints are requiring 100 rounds of teflon tape to not leak then they aren't tight enough.

And no pipe joint compound does not glue things together. It's a paste that usually contains PTFE (teflon) and doesn't harden over time. It seals a hell of a lot better than teflon tape does, and arguably is a better lubricant as well. It's also easier to use IMHO, you simply smear it all over the male end with the little brush that comes in the can. It's relatively thick and grabs on pretty well.

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Mon Dec 04, 2017 9:54 pm

I see.

For the screw in however I am still wondering. Like I said it seems like it is pinky tight loose and then suddenly it gets tight as tight it can get. I tried with french wrench - it is that tight that it barely moves a mm with a very hard pressure. Also, even if I use over 3 minutes of doing rounds of PTFE tape it literally feels like there is nothing in between and screws in as it would've naked.

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by A. Spruce » Mon Dec 04, 2017 9:56 pm

DanM wrote:
Mon Dec 04, 2017 8:33 pm
And no pipe joint compound does not glue things together.
Well . . . yes and no. The cheap stuff will absolutely weld the joint together, but the good stuff won't. Buy the Oatey brand of pipe joint compound and you'll be just fine. You can get it in tubes or jars. It doesn't go bad, but if you don't need much it doesn't make sense to buy more than you need.
https://www.amazon.com/dp/B0009QZQT0/

As for tightening, I don't know that I'd put 3 turns after finger tight. Like I said, get it good and snug, the point where it starting to offer some decent resistance and stop with the valve in the right orientation. Test for leaks, if you got 'em, give it another full turn, if not, you're done! Dan is correct, you never want to loosen a joint to proper alignment, you stop as you are tightening, hence why I recommend stopping when you feel good resistance.

NPT threads are beveled. Unlike a bolt that is the same diameter from start to end of the threads, an NPT fitting is cone shaped, so the more you tighten it the more the cones are forced into one another, creating the seal. The threaded portion (pipe) will collapse as it is forced into the much stronger outer portion (fitting).
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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by A. Spruce » Mon Dec 04, 2017 10:00 pm

kcham wrote:
Mon Dec 04, 2017 9:54 pm
I see.

For the screw in however I am still wondering. Like I said it seems like it is pinky tight loose and then suddenly it gets tight as tight it can get. I tried with french wrench - it is that tight that it barely moves a mm with a very hard pressure. Also, even if I use over 3 minutes of doing rounds of PTFE tape it literally feels like there is nothing in between and screws in as it would've naked.
I think that some of this is from tightening and loosening the joint several times. As I described in my post a second ago, forcing two cones together distorts the inner cone, which means when you loosen the parts you're going to now have to screw in farther to get it tight again.

The only other thing that comes to mind with a few of the things you've posted over the course of this discussion is to make sure that the threads are the same in all your parts, otherwise you won't get any tightening at all and you will never stop the leaks. Different types of threads are used for different purposes, so make sure everything is the same.
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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Mon Dec 04, 2017 10:19 pm

I bought them all at the same place and the people there knew what I was buying, they were actually giving me the parts. Not sure how to exactly see if the T-fitting is compatible with the valves?

And for what you say about tightening and looseing causing distorts to the inner cone, does this means that it is permanently "damaged" now?

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by A. Spruce » Mon Dec 04, 2017 10:44 pm

Once it is distorted, yes, it is permanently distorted, but that doesn't necessarily mean that it's damaged or unusable. It doesn't sound like you've gotten the parts that tight yet.

You asked about wrenches earlier, pipe wrenches will give you the bite and leverage you need to secure the fittings. You will need two wrenches, one to hold with, one to do the tightening with. Most other tools just don't have the grip necessary to hold onto round objects. You'll find that even when there is a hexagonal shape, a pipe wrench is going to hold better than anything else.

Can you post a picture of the parts you're using?
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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Tue Dec 05, 2017 12:26 am

I left home for work, so I will explain what I am using as I am picture-less.

I have a pipe inside the wall that has threads on itself, at it's end, so in order to install a valve I don't need no nut, no compression type fitting or anything like that, nothing, it simply is a self-screwing valve. So there was only one valve screwed into that thread, but I now split it in two valves with a T-fitting in order to install a newly bought washing machine. So I got a T-fitting with a screw in adapter to put it into the pipe, and then I split it in two L-shaped valves, undersink and washer.

If I hypothetically call a plumber right now, they would put a hemp and end the job in 10 minutes (I did a lot of scew in screw out, so I am not sure if I should buy new parts now). I had hemp before and it never leaked, but I wan't to try make it with a PTFE tape as I know that it works if its done properly.

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by A. Spruce » Tue Dec 05, 2017 12:58 am

It would seem that you're over-thinking or over-worrying about this project. If you had it together once and it wasn't leaking, there was no need to take it apart. Connections were made for decades before pipe dope and thread tape even existed, these things are not a necessity, they just insure that assembly goes smoothly and joints are tight without a lot of fidgeting.

Before you go replacing parts, just give your threaded ends 5+ wraps of thread tape and/or dope them, put them together as tight as reasonably possible, and be done with it. When you wrap the threads, wind in the opposite direction you twist to tighten the fittings, and apply the tape evenly across the width of the threads, a big ball at one end or the other of the threads doesn't do you much good.
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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Tue Dec 05, 2017 1:04 am

Also,

I am pretty sure I have identically the same valve for the machine as these showed here:

https://www.youtube.com/watch?v=5xWpSYsxf64

What I also wondered was, what type of valve mechanism this valve has:

https://imgur.com/a/YJfCR

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Tue Dec 05, 2017 1:19 am

A. Spruce wrote:
Mon Dec 04, 2017 10:00 pm
I think that some of this is from tightening and loosening the joint several times. As I described in my post a second ago, forcing two cones together distorts the inner cone, which means when you loosen the parts you're going to now have to screw in farther to get it tight again.
Oh, sorry, I have missed some of your posts in this thread, as I usually check my mail to reply and it did not show everything, I guess some of the replies were to other people too. Now more things make sense, but I still think that the people in the shop probably knew what they were doing, although your assumption is on point.

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by Shannon » Tue Dec 05, 2017 7:31 am

Yup Pull that out clean off the threads and put on about 5-8 wraps of tape (or use dope) and turn in by hand until pretty tight and then 2-3 more turns with wrench or less if it seems to tighten right up earlier.
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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Tue Dec 05, 2017 4:09 pm

@DanM, @Shannon, @A.Spurce.

Two last things.

As I previously noted I get either too tight or too loose connection, how normal is this? There is no gradual increase in pressure, it just feels like it hits "rock bottom" suddenly, and I need to use a wrench and even with it, its pretty tight fit at that point. Can you guys recognize what thread type is this by my description? My main valve is split with my neighbors and I cannot shut-off the water at this moment to take a picture and show you the threads of the valves and fitttings.

And what valve type was the one that I linked in the previous post?
kcham wrote:
Tue Dec 05, 2017 1:04 am

What I also wondered was, what type of valve mechanism this valve has:

https://imgur.com/a/YJfCR

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by A. Spruce » Tue Dec 05, 2017 4:43 pm

Pipe threads are tapered, the inside taper gets crushed by the outside taper which is what makes the seal. Because you've tightened and disassembled the fittings several times, the pipe being screwed into the fitting has been crushed, so it's going to be easy to turn until you get up against the portion that has not been crushed.

You said that you've Teed off the pipe from the wall to have two valves. I assume you put the Tee on the wall pipe, nipples into the Tee, then are attaching the valves to those nipples. The nipples are what are being crushed, so if you replace those with fresh ones you should be able to thread tape and assemble everything in one go, tighten until they feel good and tight and the valves are in the proper orientation. Test your work, if there is a leak, give the valve at least a partial turn to tighten more. If you take the valve handle out of the 12 to 3 o'clock position, go a full turn more.

The valve in your image appears to be a ball valve, same for the video.
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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Tue Dec 05, 2017 4:57 pm

Yes I Teed off the pipe into to valves, but I have a nipple only between the wall pipe and the tee, the valves screw in the tee without any nipples. So if the damage is done, it should be done to the valves. ;/

About the old valve, what is the use of that mesh in one of the pictures, I have never seen one like that, and yes it is open.

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by A. Spruce » Tue Dec 05, 2017 5:09 pm

Well, you have three choices then, either keep twisting the valves until they don't leak, regardless of where the handle lands, or, give them a full turn to keep the handle in either a vertical or horizontal position where it is easy to operate, or, replace the valves for new and be careful about how you install them so that you do it only once.

I would guess that the screen is a particle filter to keep chunks of rust and debris out of the valve. I have not seen that feature before, so I'm only guessing.
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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Tue Dec 05, 2017 5:55 pm

Can too much PTFE damage or disform them? You said I have two options, does the option to take them off & remove the 100 rounds of PTFE and re-apply just a few like it is recommended and try again is not possible at this point?

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by A. Spruce » Tue Dec 05, 2017 6:02 pm

As earlier discussed, the tape will have no bearing on the integrity of the joint. The purpose of the tape is to lubricate the threads so that you can get them tighter. While it does have some sealing properties, it is not capable of filling large gaps nor deforming the parts involved. Deformation of the parts comes from tightening them, hence why you don't want to be disassembling them unnecessarily.
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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by kcham » Tue Dec 05, 2017 7:57 pm

Thank you! One last thing I forgot to mention is that the other old valve was very very loose, less than finger-tight, and it never leaked and I never checked before the other day. The plumber used hemp, but I wondered if there was any reason he did not screw it a lot and why it did not leak, I don't remember him trying to see if it will leak, he did it one take. Other valves I have in the same and other bathroom are tightly sealed, by other plumbers from the past (for measure).

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Re: Unwaxed vs waxed hemp vs teflon tape on shut-off valve fitting?

Post by A. Spruce » Tue Dec 05, 2017 8:31 pm

Hard to say why a loose fitting wasn't leaking, good luck for you! It is always a crap shoot with plumbing as to whether or not it's going to cooperate and seal as it should, hence why I tighten things minimally and add more if necessary. Doing it this way gives you the option of adding more torque without the fear of breaking something.
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