Sealing vent liner threads

[mjm46@bellsouth.net]

I was just re-reading some old posts about vent liner installations and all the controversy about bottomong or not.

I usually install them with a little choke tube lube to make them easier to remove in the future if it ever wears out. After reading all the controversy from the past a crazy idea came to me. Has anyone tried installing liners using pipe sealer on the threads? It would seal the threads and is non hardening so it would allow future replacement and is somewhat heat resistant. It would stop inflitration of fouling into the threads, that some considered a problem. It's water proof and will not wash out when cleaning.

Would this work for seal on breech plugs?

This is probably non traditional but seems like it would work, any comments?

[Don Getz]

I can recall that John Bivins used pipe dope on breech plugs.   At the time he was using Paris barrels and they used the
coarse threads in their barrels....5/8x11, 3/4x10.  It is almost impossible to make these coarse threads waterproof.....
Don

[mjm46@bellsouth.net]

Can there be any downside to using pipe dope on these threads?

[Dennis Glazener]

I have used teflon tape like plummers use today in place of the old pipe "dope". Sure seems to help tighten the barrel, much smoother.
Dennis

[4ster]

I put anti seize compound on mine. 

[alsask]

I usually use copper coat anti-sieze when putting them in.  It doesn't take very much.

[Long John]

Loc-tite 242

It is designed to do exactly what we want it to do - fill the space between the male and female threads, seal and yet be removable.  It fulfills all of those objectives.

Best Regards,

John Cholin

[Roger Fisher]

I have used teflon tape like plummers use today in place of the old pipe "dope". Sure seems to help tighten the barrel, much smoother.
Dennis

Yes, teflon plumbers tape works for me on liners but never had the need (happily) to use on breech plugs ugh!. 

[Dphariss]

I was just re-reading some old posts about vent liner installations and all the controversy about bottomong or not.

I usually install them with a little choke tube lube to make them easier to remove in the future if it ever wears out. After reading all the controversy from the past a crazy idea came to me. Has anyone tried installing liners using pipe sealer on the threads? It would seal the threads and is non hardening so it would allow future replacement and is somewhat heat resistant. It would stop inflitration of fouling into the threads, that some considered a problem. It's water proof and will not wash out when cleaning.

Would this work for seal on breech plugs?

This is probably non traditional but seems like it would work, any comments?

Do it right in the first place.
Then goo is not needed in the threads.

Dan

[flehto]

I agree w/ the above.  Don't tap completely through to the bore and have the  last  threads shutoff on the liner. The bevel also shuts off. Nothing else needed.....Fred

[chuck-ia]

What about red loctite? I would think it would strengthen the threads, and provide a good seal allso. I have used anti sieze on both breech plug and vent liner in the past. I put a white lightning liner in the current gun I am working on this past Sunday and used red loctite, (gasp). Seems most want to be able to remove liner if needed, and to seal. I would think loctite would provide a better seal, and still be able to remove, (with a little heat). I will stick with a gasget sealer or anti sieze on the breech plug however. I know loctite is not traditional, nor is antisieze. Any downside to loctite? chuck

[Acer Saccharum]

On a Chambers liner, you don't 'bottom them out'. I use loctite on a Chambers, as it ain't ever coming out, unless I'm replacing it.

Other designs may, depending on how they are made. Dan Phariss does a neat job with a bottomed out liner.

[Dphariss]

What about red loctite? I would think it would strengthen the threads, and provide a good seal allso. I have used anti sieze on both breech plug and vent liner in the past. I put a white lightning liner in the current gun I am working on this past Sunday and used red loctite, (gasp). Seems most want to be able to remove liner if needed, and to seal. I would think loctite would provide a better seal, and still be able to remove, (with a little heat). I will stick with a gasget sealer or anti sieze on the breech plug however. I know loctite is not traditional, nor is antisieze. Any downside to loctite? chuck

Unless the maker reduces the number of threads engaged or there are diameter issues between part and hole strength is not a factor. Leakage is. The problem with WL is that they are very thin at the large end of the cone and loctite might result in only part of the liner coming out when its removed. They are so thin, well into the cone that there is really no way to shoulder them.

Using stud and bearing type loctite may result in the part needing heat to 400+f to remove.
The other problems is that none of these will seal oil/fouling traps since loctite only sets if cut off from oxygen.
 So its not a gap sealer really except in areas where the loctite is not easily exposed to oxygen, back in the threads.
But it will keep fouling or liquids from migrating back into the threads.
But its still just a bandaid and people need to remember that.

If the threaded part is installed properly then only some lubricant need be applied to the threads, oil, STP or anti-seize. Does not really matter.

Dan

[FL-Flintlock]

For pass-through threaded connections like a b-plug or vent liner, optimum thread sealing is achieved with a chemical cure adhesive/sealant like EAS6500F and it's not susceptible to shock-load failure as is common to common locking/sealing and pipe thread sealants.  Small amount applied to the female threads provides seal on the leading edge; male threads are doped as normal, excess can be wiped off the outside.  It'll withstand the pessure & heat of firing, to remove is just a matter of using sustained heat of 350°F.  Aerobic sealing/locking compounds won't cure beyond about half a thread into the joint and anaerobic compounds typically won't cure and seal the leading edge and first half to full thread.  Cured aerobic and anaerobic sealing/locking compounds can often be degraded enough for removal by soaking in Methylene Chloride or Dimethylformamide if heating is not an option.  Low-order anaerobic compounds are usually susceptible to methyl ethyl ketone (MEK).  MEK & toluene will break down aerobic compounds, lacquer thinner may work but is much slower.
Mark

[mjm46@bellsouth.net]

If the threaded part is installed properly then only some lubricant need be applied to the threads, oil, STP or anti-seize. Does not really matter.

Dan

Dan, could you please discribe your process.

[Dphariss]

http://americanlongrifles.org/forum/index.php?topic=9866.0

This thread give the basic idea.

But some barrels are not thick walled enough and the WL is so thin walled that shouldering is a waste of time.
The vent must have a counter bore that is the same or slightly smaller than the hole through to the bore to prevent fouling traps. WL liners really do no allow this with their large counterbore.
Shouldering the liner greatly reduces the gas pressure on the liner and prevents any leakage into or past the threads.
But it takes several times as long to install. The same is true of shouldered breechlugs as well. As a result many people, including some barrel makers, do not bother.

Here is a period drawing of an Nock Breech in a shotgun barrel. Liner has no counterbore. But its shouldered.

The breech threads are not shouldered and this has been discussed in another thread recently. Its nearly impossible to do with modern thread clearances and get the result obtained in the past. Its also impossible to shoulder a the breech threads in a thin wall barrel and maintain integrity. Typically as shown here the bore was the tap drill.

Here is a counterbored liner that is not shouldered.

But note that all threads as shown as filled. But its just a representative drawing an intended to be 100% accurate I suspect. But filling all of the female threads is a very good idea. Otherwise cleaning can be difficult.
Dan