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Thread Sealant Application Method

rapid_ascent

Well Known Member
I have a basic question about the application of thread sealants. I'm using some loctite thread sealant on my NPT fittings. I don't recall the exact number at the moment. I apply a small bead of sealant all the way around the fitting about 2 threads up from the end of the fitting which I believe is the proper method. I've tried to not use too much sealant but yet form a complete bead all the way around the fitting. That part I think I'm doing correctly. I then thread the fitting into the mating fitting and a small bead of sealant forms on the external surface. My question has to do with this bead of sealant and the proper method to deal with it. I've been wiping off the bead of sealant once the fittings are fully mated. I figured I should check to see if this is an acceptable process to follow before I get the entire fluid system installed using the wrong method.
 
You're doing it right. Doesn't take much, and the part about leaving the first two threads dry is really important.

I'm happy with leaving the bead of sealant in place, but it won't hurt to wipe it off. Typically, I use Loctite 567...since it sets up anaerobically, that external bead that's exposed to air always stays a little gooey.
 
More specifics

After having several leaky brake fittings and failed attempts at fixing them, i was shown what i believe is the proper way to apply thread sealant. Just using the tube and placing sealant around the threads didnt work for me. What was needed was using your finger and pushing it into the threads all the way around the fitting. Then clean any off on the first couple of threads. Doing This finally corrected my leaky fittings. Try it - Nothing to lose.
Robert Paisley of EFII demonstrated the procedure and Rightrudder, above, can attest to my troubles. 2 months and 30+ hours with NO leaks.
 
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