Thread sealant help

DanB

DanB

New member
Howdy all. I'm working on a project and can't seem to get a thread to seal. It is a 1/8 npt thread cut in 7075 aluminum. I have used teflon tape to no avail. Any sealant suggestions would be appreciated.
Dan
 
teflon tape isn't a good thread sealant, get a tube of pipe dope, it will stay in the threads and seal alot better. the npt thread is a tapered thread and should just about seal on its own but the pipe dope which you can use most types will stay in the threads and should make a gas tight seal
Fred B
 
Try Locktite 545 or Hercules Megaloc and Real-Tuff. Also, a great deal depends on the quality of the fitting and the threads. Even correct torque values on inferior parts will not create a leak free joint.
 
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cris said:
Try Locktite 545 or Hercules Megaloc and Real-Tuff. Also, a great deal depends on the quality of the fitting and the threads. Even correct torque values on inferior parts will not create a leak free joint.
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Part of the problem may be the quick fill that I'm screwing into the rig. It is a cheap paintball fitting with rough threads. Thanks for the info.
Dan
 
I generally always get a decent seal using two and a half wraps of 1/5" wide teflon tape. I wrap in the thread direction and spray a spritz of Rem Oil on the wrap before screwing it in.
 
Have you given any though about a O -ring seal at the shoulder of the bottle . One paint ball bottle supplier has told me that his bottles are sealed with a O ring and are not tight on the rifle with out air pressure making them so .
 
therealld said:
I generally always get a decent seal using two and a half wraps of 1/5" wide teflon tape. I wrap in the thread direction and spray a spritz of Rem Oil on the wrap before screwing it in.
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Thanks. I am getting better results with more wraps. I have one fitting sealing, wrapped about four times. I also tried a little lube on the outside of the tape.
Dan
 
RIng said:
Have you given any though about a O -ring seal at the shoulder of the bottle . One paint ball bottle supplier has told me that his bottles are sealed with a O ring and are not tight on the rifle with out air pressure making them so .
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HI Rick. I'm trying to seal pipe threads, there are no provisions for o rings. Going forward I may use fittings that employ bonded seal washers.
Dan
 
Dan, if your useing more wraps to get a seal then that tells me that the aluminum has compressed and the threads are oversized. there's not much more you can do ,but be prepared to tear it down because teflon tape will come off in very tiny hairs and will travel downstream and find the first valve to lay in the seat and will cause leaks there and any other valves. the use of pipe dope alleaviates this.
 
FredB said:
Dan, if your useing more wraps to get a seal then that tells me that the aluminum has compressed and the threads are oversized. there's not much more you can do ,but be prepared to tear it down because teflon tape will come off in very tiny hairs and will travel downstream and find the first valve to lay in the seat and will cause leaks there and any other valves. the use of pipe dope alleaviates this.
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I will order some of the loctite 545 and see how that works. Thanks all for the help.
Dan
 
I'd stay away from loctite and similar compounds, if you try and take it apart it may take some aluminum with it. I'd go to the local hardware store and get some there in the plumbing dept.
 
I once attended a two-day seminar put on by Loctite corp. Many loctite sealant formulations are not just "glue" or goop, but rather, work by means of a chemical (usually oxidizing) reaction. They sometimes even include abrasive particles in the compound to scratch up the surface so as to expose raw metal to expedite the reaction.

I too prefer to not use loctite sealant where I plan to re-open the joint periodically.
 
therealld said:
I once attended a two-day seminar put on by Loctite corp. Many loctite sealant formulations are not just "glue" or goop, but rather, work by means of a chemical (usually oxidizing) reaction. They sometimes even include abrasive particles in the compound to scratch up the surface so as to expose raw metal to expedite the reaction.

I too prefer to not use loctite sealant where I plan to re-open the joint periodically.
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I ordered 561 sealant, it supposedly is designed to separate freely.
Dan
 
Thanks Dan,

I wasn't aware of the stick type sealants they now have. I read it seals to 100psi right away, and up to 10,000psi in 72hrs. Sounds like something good, pls let us know how it works for you.
 
therealld said:
Thanks Dan,

I wasn't aware of the stick type sealants they now have. I read it seals to 100psi right away, and up to 10,000psi in 72hrs. Sounds like something good, pls let us know how it works for you.
Click to expand...

What I may end up doing is rethreading the holes to a larger size and make my own fittings with o-rings, case solved. If I end up using the sealant I'll let you know how it works.
Dan
 
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