Grohe offset Shower Adapter Serrated Thread

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g00f

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Anyone know what I should use on the serrated threads when I screw it into the brass connector which is soldered to my cu pipes? I tried teflon tape but it still leaked alot, so I added even MORE tape 2 more times and it still leaked.

Do I need some type of doping compound? I really tightened it the last time, and the water was still coming thru enough that I couldn't mount it.

This is for an Italian made external thermostatic shower head/unit(?) that sits external to my wall. Thanks for your assistance.

Heres a picture of the adapter and its "unusual" thread.

grohe-exposed-shower-1.jpg
 
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Shacko

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Are you shure that is an american thread? a lot of imported threaded parts are cut with the foreign thread and they will never work with the U.S. cut.
 

Jadnashua

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Neither of those threads look like they are tapered. They are probably designed to compress a washer, similar to a hose on a hose bib.
 

hj

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There is NO way those serrated threads will NOT leak, no matter how much tape or coupound you put on them. If they are not supposed to leak, the the seal MUST be something and somewhere other than those threads.
 

Jadnashua

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I have a similar fitting on my Grohe external tub/shower valve. There is a piece you screw into the standard fitting that then accepts this offset piece. The offset piece (on mine) came with a gasketted bronze filter screen that both filtered crud from getting into the valve, and the gasket provided the seal to keep it from leaking. This works exactly like the seal use to attach a hose to your outdoor faucet. As noted, you will not get those threads to seal, but the end is probably designed to tighten against a gasket. In that case, the threads just provide the means to compress the seal at the end...they don't do any sealing in and of themselves.
 

g00f

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Got it fixed, thanks for everyone's excellent suggestions.

I went back to the place I got it, a distributor who has a yearly warehouse sale (I go every year regardless if I need anything, and always buy something ;) ); their technicians said to use the pink T-Tape, and in the end that's what works, the white T-tape I had was way to thin I guess for this application. I just tightened it enough to line them both up and Voila...perfect. I asked about washers, but they said they are needed but for the other side of the offset connection, and that's where there's already some wire filters going into the unit, so good to know about that also.

Here's the leak free attached offset adapter.

And the thermostatic shower unit attached...its a heavy unit, and really needed some strong framing around it.

grohe-exposed-shower-2.jpg
 

hj

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If you used tape on the "notched" threads and it did not leak, then you have to be one lucky person, because they should not have sealed, regardless of the tape's color.
 

g00f

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Thanks for the info HJ,

I will not be putting up the drywall for another week or two but will have the water supply on till then and monitor for leaks. I was quite surprised that it worked this time versus previous attempts, so will be very cautious and test it over the next couple weeks.

Should I add an liquid sealant also for an additional sealant, maybe something above and below the pink T-tape? Would that help?
 

hj

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Threads seal by a metal to metal seal along the entire thread. Those grooves should create PERFECT channels from the top to the bottom for water to leak through, and thus NOTHING should prevent the leaks. The only way I can see, looking at your picture, would be for something to fill the grooves, and whatever that was would have to stay there FOREVER to prevent future leaks. I do not know anything that would do that.
 

Jadnashua

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I still say that doens't look like a tapered pipe thread, and thus, the tape, as HJ indicates, is questionable for a long-term connection. I still think that it should screw into a socket with a gasket on the end to seal it like a hose does. This isn't (at least in the US) a typical plumbing connection.
 

SteveW

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Thanks for the info HJ,

I will not be putting up the drywall for another week or two but will have the water supply on till then and monitor for leaks. I was quite surprised that it worked this time versus previous attempts, so will be very cautious and test it over the next couple weeks.

Should I add an liquid sealant also for an additional sealant, maybe something above and below the pink T-tape? Would that help?



When you are monitoring the situation, make sure you check for the condition where someone shuts off the shower head with the shower valves still open. (Some shower heads have such a shut-off to conserve water when you are soaping up; also, some homeowners add a separate shutoff before the shower head for the same purpose.)

The pressure in the system will be much higher than it is when water is running and may cause leaks which would not appear otherwise.
 

Jonathan L.

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This link explains what to use. I'll be searching my box of parts for the card with the "cord seal" string material. Hope that helps...

 
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