Sealing damaged threads

ChrisJ

If I want to seal a very questionable NPT connection with damaged threads, what would you use?

I was thinking RTV but maybe there's a better product out there?

STEVEusaPA

Water? I like what I call lamp wick.

dko

anaerobic thread sealants like Permabond

ChrisJ

STEVEusaPA said:

Water? I like what I call lamp wick.

Low pressure air, a few pounds or so.
If it seeps it's not the end of the world but I'd rather it didn't.

HomerJSmith

The only thing that has ever worked for me with great success is Lock-n- Seal or Locktite. Clean all the threads well and rinse with lacquer thinner.

mattmia2

Lampwick and dope will work the same as lampwick with water. I think there is a very fine teflon cord out there that you can lay in the threads like lampwick too.

Alan (California Radiant) Forbes

Hernon Dripstop 923 or Superdope, both anaerobic. Usually hand tight will do it. 

realliveplumber

Blue Block thread sealant by Hercules
https://www.zoro.com/hercules-all-purpose-high-performance-gasket-sealant-4-oz-blue-temp-range-90-degrees-to-450-degrees-f-15703/i/G7510386/?utm_source=google&utm_medium=surfaces&utm_campaign=shopping feed&utm_content=free google shopping clicks&gclid=EAIaIQobChMI7KKXrazI_gIVPMfjBx25bgnZEAQYAyABEgL89PD_BwE

pecmsg

M or F thread?

Mad Dog_2

For that application Permtex and blue monster  Teflon tape  md

pecmsg

I’ve used Stainless Steel fittings to clean up rough copper and brass threads. 

Karl Reynolds

X-PANDO. It's a powder that you mix with water. It swells as it sets.

EBEBRATT-Ed

If you dont think you will have to ever take it apart use X-Pando as @Karl Reynolds mentioned

ChrisJ

pecmsg said:

M or F thread?

Kinda both...

mattmia2

what is this part?

Big Ed_4

Run a tap or die to recut the threads if you can . The threads are more important ..

gerry gill

We use high temp permatex gasket maker for that.

SSmith

I have used X-Pando in the past, it certainly works, but seems brittle as it sets, now I use wire brushes to clean the male threads, then a light layer of teflon dope. Then wrap with four to five winds of 'flax' aka hemp, then another light layer of dope to hold the stuff in place. The hemp fibers are not woven as dense as rope; it actually looks like a disassembled hemp rope. Not to be confused with Oakum as it is dried not oiled or waxed. I used it working in Ireland and it is popular all over the EU (and England) to deal with their BSP threads. The hemp expands when exposed to moisture and seals up nice!

Steve_Wheels

XPando! Works great to 600F! Works on HP Steam! Great stuff!! If you ever want to take the fittings apart, put your pipe wrenches on the pipe and fitting, have someone tap the fitting three or four times with a hammer and presto, comes right off.

MrStu02

If possible, chase the threads first. Tap and die. Then, as I do for all threaded connections in hwh, apply a leak lock sandwich. We use a hardening type of pipe dope called “Leak Lock” on the male threads, followed by a layer of the pink Teflon, and covered with another layer of Leak Lock. Best used during installation as some time is required for the leak lock to harden.

eclecticmn

Homeowner here. I bought some used cast iron hot water radiators. I could not get the replacement 1/8(?) inch bleeder valves to seal. Did not trust my skills so hired a mechanic off craigslist to drill and tap next size up 1/4(?) inch for bushing. That leaked around the bushing with tape and blue monster dope. I used two part JB Weld epoxy around the bushing and it worked. Any thoughts on that? Should I have used red Loctite?

Also, I know what the word anearobic means but why is it used here?

mattmia2

eclecticmn said:

Also, I know what the word anearobic means but why is it used here?

There is no air in the parts of the threads you want to seal. It is basically super glue.

CLamb

ron said:

pecmsg said:

M or F thread?

quite insensitive of you to assume his fittings are only one of two possible genders. That's probably his problem - not recognizing the correct gender of the fittings is why they are leaking.

That's what came to my mind when @ChrisJ said they were "Kinda both...".

Jackmartin

The best sealant for damaged threads is expanding. We use to buy the stuff in 50 pound caskets in the ammonia trade put it on leave it for 24 hours no leak. Expanding is a type of cement it hardens like concrete and you cannot get it loose without hearing checkpoint to 300 degrees if it will seal ammonia at 400 psi it shpuld work for you

mattmia2

Is that how this happens:
https://www.mlive.com/public-interest/2023/04/ice-maker-arctic-glacier-fined-232k-over-michigan-ammonia-spill.html

ChrisJ

Does X-Pando have a long shelf life?

EBEBRATT-Ed

@ChrisJ It's a dry powder that mixes with and absorbs water. I think it will last as long as it is kept dry.

jumper

US and other governments have gone rogue. What's wrong with six hours? What will be different between six hours and six minutes.

It often takes weeks to reach a bureaucrat. Phone mailbox is full when its system even works. Best way is ordinary mail –forget registered– and then somebody will call weeks later.