Best thread sealant?

[Bigmatthew86]

I’m in the process of changing the unloader on my old Futura. What is the best stuff to use to seal the threads on everything? I’ve got regular Teflon tape, yellow Teflon, Blue demon Teflon tape, pipe dope? I used white originally an have some small leaks. What do y’all recommend?

 

[slash007]

I stopped using white years ago. I use blue for everything, then put pipe dope on top if it's 1" or larger. Sometimes even if 3/4" depending on application.

 

[MEP001]

Blue Monster. It's thicker than cheap white, so don't overdo it. It never hurts to use both tape and dope on any size fitting, I don't because I hate the mess. I use a lot of tape, so I bought enough rolls from supplyhouse.com to get free shipping. I also got some 1/4" for smaller fittings so you don't see the thread tape at the guns and wands in the bays.

 

[Bigmatthew86]

Blue monster with some permatex 80632 over top. Hopefully that’ll stop it.

 

[soapy]

Pipe dope with blue monster over the top. Less messy that way.

 

[MEP001]

Another option is blue Loctite. There are some drawbacks, if you tighten the threads together really hard it can be difficult to disassemble, but not impossible. If you move the threads after it's cured, it will leak, but again it's pretty hard to move them if you tighten it up hard. I don't routinely use it, but I use it when building new equipment, anything that won't get taken apart again gets Loctite. I've assembled many, many thousands of brass fittings with Loctite and never once had a leak.

 

[JCW]

Really like Blue Monster with this pipe dope for larger fittings.

 

[Randy]

We use “Leak Lock” https://highsidechem.com/leaklock/ on a lot of our fittings. We’ve been using it for well over 40 years. Works great

 

[Bigmatthew86]

So after putting it back together I gave it a day to cure before I fired it back up. Fixed all the leaks except the larger (3/4” I think) line at the swivel. I’ve tried to find a replacement end but no luck. Look like that end is the screw on type but I couldn’t find one. All for smaller hoses.

 

[MEP001]

Pipe dope doesn't cure. You can run it immediately.

 

[Bigmatthew86]

I know but it was a little tacky so I waited anyway. Can you point me in a direction for the high pressure fitting?

 

[MEP001]

I know but it was a little tacky so I waited anyway.

Pipe dope stays tacky forever.

Can you point me in a direction for the high pressure fitting?

What do you mean?

 

[Greg Pack]

Could be a JIC fitting or SAE fitting which will need the proper adapter to not leak. I only use NPT so I'm not good at telling the difference. Mep can probably look at the female and tell.

 

[cantbreak80]

Apply tape/dope to NPT fittings only.

Do not apply tape or dope on JIC or “non-working” swivels.

The tape/dope prevents the tapered faces from making full contact.

And, always remove the wad of tape from a reused fitting.



You’re welcome.

 

[MEP001]

Could be a JIC fitting or SAE fitting which will need the proper adapter to not leak. I only use NPT so I'm not good at telling the difference. Mep can probably look at the female and tell.

The fitting in the foreground does look like it could be a flare on the hose end. It wouldn't be the first time I've seen someone put a 3/8" flare hose end over a 3/8" NPT fitting.

 

[Bigmatthew86]

It’s not leaking at the threads. It’s leaking at the actual swivel. It wasn’t leaking before but it probably hadn’t been touched since 98. I disturbed it & now is dripping there.

 

[MEP001]

If that's a swivel fitting with male pipe thread on the hose, the swivel is bad. You'll have to get a new fitting crimped onto the hose, or replace the hose. I use a non-working swivel on those. Don't put thread tape on the male threads that go into the female part of the non-working swivel.

 

[Keno]

If that's a swivel fitting with male pipe thread on the hose, the swivel is bad. You'll have to get a new fitting crimped onto the hose, or replace the hose. I use a non-working swivel on those. Don't put thread tape on the male threads that go into the female part of the non-working swivel.

Are you saying not to put tape on the male threads of a non-working swivel npt fitting? I've always used tape on all npt fittings. Is that not correct procedure?

 

[MEP001]

Seal is here, don't tape the fitting that goes there:

 

[Keno]

I have been using tape on both sides of that non-working swivel fitting, since both sides are usually npt fittings. It's been working fine for me, but I never put tape on the first couple threads anyway. Will taping hurt anything?