Best way to plug a barrel for immersion

[Larry (Omaha)]

Coming up on my underhammer project will be a hot rust blue treatment for the metals. I have never immersed a barrel in boiling water and want to make sure my plugs and precautions will be 100% effective against water entering the bore. I am thinking about using a rubber cork for the barrel ends and also for the nipple placement. The fact that the bore has rifling, and the nipple has threads makes me concerned about getting a total seal. What is the best material to add to the rubber cork to complete the seal? I am thinking maybe pipe dope? Am I starting with the wrong material? What is the best way to go?
Thanks in advance
Larry

 

[Cpt Flint]

We have never plugged one and never had a problem. Make sure the bore is well oiled and clean immediately after it comes out. If you already have it plugged proceed and don’t overthink it.

 

[kje54]

Coming up on my underhammer project will be a hot rust blue treatment for the metals. I have never immersed a barrel in boiling water and want to make sure my plugs and precautions will be 100% effective against water entering the bore. I am thinking about using a rubber cork for the barrel ends and also for the nipple placement. The fact that the bore has rifling, and the nipple has threads makes me concerned about getting a total seal. What is the best material to add to the rubber cork to complete the seal? I am thinking maybe pipe dope? Am I starting with the wrong material? What is the best way to go?
Thanks in advance
Larry

I use a piece of wood dowel (or square stock, whatever I happen to have on hand) carved to a conical flat point on one end. I do the same for the touch hole/nipple hole only smaller (obviously). With the muzzle plug just tap it in with a mallet, with the touch/nipple hole I screw it in after removing the nipple or liner.

 

[user 34300]

Water will not hurt the bore. Don't try to plug it. The heat will expand the air, pop the cork and splash boiling water.

Don't put a bunch of oil in the bore. The oil will come out into the water and and spoil the bluing. Just clean and oil the bore after.

I have read about putting lacquer in the bore. IT can be easily removed with lacquer thinner. I have never bothered. It would not hurt though.

 

[Col. Batguano]

Try one of those rubber wine corks with a cam on the end. When you cam it down, the rubber compresses and expands. It seems that wine bottles are about a 71 caliber.

You could make one yourself by drilling through your (sub caliber) rubber cork, putting a 1/4" threaded rod through it, a washer on each end, and then a nut on each end. You could even double-nut the bore side or Loctite it. Twist down on the nut (on the muzzle side) and the rubber will compress and expand to give you a good seal.

 

[rchas]

The heat will expand the air, pop the cork and splash boiling water.

This WILL happen and you will get water in the barrel anyways. I have rustblued several barrels, both muzzleloader and unmentionables, and never had a problem. The black oxide, even if some develops in the bore, doesn't affect accuracy. After the last boil and carding my barrels go directly, still hot, into a motor oil bath for a day or two. A thorough cleaning afterwards and they are good to go...

 

[ZUG]

As Scota@4570 said don't waste your time trying to plug the bore. I've rust blued many barrels plugged and unplugged and no harm has become to the unplugged barrels. Think of it as just cleaning your barrel after a days shooting - just dry it good
.

 

[The Crisco Kid]

I've never plugged a barrel for rust bluing. I give it a good coat of car wax and suspend the barrel from a piece of cold rolled rod. Never had a problem. I do run a patch down the bore to dry it fast after I take it out of the boil.

 

[Larry (Omaha)]

Water will not hurt the bore. Don't try to plug it. The heat will expand the air, pop the cork and splash boiling water.

Don't put a bunch of oil in the bore. The oil will come out into the water and and spoil the bluing. Just clean and oil the bore after.

I have read about putting lacquer in the bore. IT can be easily removed with lacquer thinner. I have never bothered. It would not hurt though.

Thanks for the great advice! I know heat causes expansion, but had my head in the sand about that fact. I am not concerned about the water, cuz most of us clean with water. I was (not now) more concerned with the rust bluing chemical getting into the bore, breech and nipple areas.
Thanks again

 

[BS]

Have you thought about Steaming Rust Blue?
More info at:

www.rustblue.com

 

[Larry (Omaha)]

As Scota@4570 said don't waste your time trying to plug the bore. I've rust blued many barrels plugged and unplugged and no harm has become to the unplugged barrels. Think of it as just cleaning your barrel after a days shooting - just dry it good
.View attachment 72166

Nice way to do the hot dunk! May I ask if there is a Mrs who permits this??

 

[Larry (Omaha)]

Have you thought about Steaming Rust Blue?
More info at:

www.rustblue.com

No, I didn't even know about it, until your post. This will be my first rust blue job and I have already selected my product and method.
Thanks for your suggestion.

 

[Booneliane]

I’ve used foam earplugs to plug appropriately sized holes with good success.

A large bored muzzleloader they probably wouldn’t work on.

 

[Valkyrie]

You could fill the barrel with sand and plug it.

 

[muzzlecap]

I used to plug barrels when boiling and quit. Never had a problem so far with barrels unplugged. Just dry well between boiling's.

 

[mooman76]

I used a bolt that fit in the place of the nipple and took a lead RB one size bigger and tapped it into the bore. Not all the way just enough for a good seal.

 

[Gvilleddie]

I, also want to try this finish. The only problem I see is finding a container to boil a 28” barrel. Suggestions?

 

[gkterry]

Perhaps, gutter could be used with end caps??

 

[user 34300]

You could fill the barrel with sand and plug it.

Is this a joke??

 

[Valkyrie]

Is this a joke??

No. The sand would displace any air that might expand and force a plug out of the barrel while in the hot bath. Likewise any other fine medium could be used like walnut blast media or similar. Just a thought.