What is correct way to use thread sealant?

[fruitcakesa]

No doubt I will get flamed for this but it worked.
After 3 attempts using paste to seal a fitting on one of the rear remote hoses , I ended up getting it to seal with tape and a thin coat of paste.

 

[sixdogs]

No doubt I will get flamed for this but it worked.
After 3 attempts using paste to seal a fitting on one of the rear remote hoses , I ended up getting it to seal with tape and a thin coat of paste.

Wow and good to hear. I'm the OP that started this thread with the intent of using thread paste but it leaked so I wound up with tape the same as you. The tape sealed it but the paste alone did not. I figured I did something wrong but didn't want to say so.

I will say the Loctite paste mentioned is great but not on my large diameter brass to brass fitting.

 

[TractorGuy]

As a follow up here to the excellent advice offered, here are some things I learned. I'm the OP.

When you tighten fittings, the join in compression ones (JIC) need to be tightened to about the same tightness as a spark plug. That's what I did and no leaks. Pipe thread brass to pipe thread brass is maybe half again tighter but err a little less and tighten if they weep. One of my brass thread to thread fittings had a small leak but I snugged it up and no follow up leaks. All is good and happiness is a leak free hydraulic connection. Thanks for the great advice.

I am late to the thread but sounds like the OP figured it out.

I don't think many if any factory hydraulic systems will have pipe threads. As Gary Fowler pointed out, thread "sealant" is actually a lubricant for use on pipe threads. You should never use tape or dope on anything BUT pipe threads. Most factory systems will have some combination of oring or JIC connections.

Both of my tractors have oring boss to oring face seal adapters. (ORB to ORFS) I used a couple of ORB to pipe adapters on my diverter but only because I had a couple of hoses the right length with pipe thread ends. I put a few turns of tape on them.

 

[fruitcakesa]

I am late to the thread but sounds like the OP figured it out.

I don't think many if any factory hydraulic systems will have pipe threads. As Gary Fowler pointed out, thread "sealant" is actually a lubricant for use on pipe threads. You should never use tape or dope on anything BUT pipe threads. Most factory systems will have some combination of oring or JIC connections.

Both of my tractors have oring boss to oring face seal adapters. (ORB to ORFS) I used a couple of ORB to pipe adapters on my diverter but only because I had a couple of hoses the right length with pipe thread ends. I put a few turns of tape on them.

This is what my fittings are.

 

[/pine]

Wow and good to hear. I'm the OP that started this thread with the intent of using thread paste but it leaked so I wound up with tape the same as you. The tape sealed it but the paste alone did not. I figured I did something wrong but didn't want to say so.

I will say the Loctite paste mentioned is great but not on my large diameter brass to brass fitting.

Is there a cure time noted on the paste instructions?...most plumbers will tell you that NO sealant is needed on brass to brass connections...

 

[fruitcakesa]

Is there a cure time noted on the paste instructions?...most plumbers will tell you that NO sealant is needed on brass to brass connections...

There is no mention of cure time on the paste I used.. It says "Non-hardening remains flexible"
5,000 psi gases, 10,000 psi with liquids

 

[PILOON]

Don't laugh,
Lacking sealants and tape I looked around my shop and noticed an open tube of polyurethane house caulking.
I dabbed some onto the pipe thread fitting and VOILA, good seal no leaks!

Shucks in the old days thickened oil based house paint was used until all sorts of brand name products were hyped.

But, YES, the O ring (or crush washer) parallel fitting with lock nut is still the best.

 

[/pine]

It should be noted that threaded fittings (especially tapered threads) are not meant to be reused excessively...the mere mechanics of NTP threads slightly distorts the threads each time they are torqued tight...
...Even fittings like JIC flares can become distorted (not necessarily the threads) from repeated loosen/tighten cycles...

 

[sixdogs]

Is there a cure time noted on the paste instructions?...most plumbers will tell you that NO sealant is needed on brass to brass connections...

Mine leaked without the tape. The use is for a loader hose "quick attach" box. Great idea but Kubota uses brass to brass adaptors which is a little awkward but it works.

 

[Cat_Driver]

I alwats use BOTH tape and liquid on everything hydraulic and plumbing including high pressure misting pumps, never a leak. If I just use one of the two I often have leaks.