vent fix

[coopersdad]

I installed a 1/4" Chambers liner, and all went perfectly except for the loose nut on the drill press, who skillfully got the hole 1/16" too high; I can see about half the hole when the frizzen is closed.....

So, I thought of making a threaded plug to fit the existing threads and countersink, and then re-drilling the touch hole, lower but at a bit of an upward angle to be closer to the center of the plug, and coning from the inside with a Snyder coning tool.  My fear here is if I don't get the angle just right, the cone may cut into the threads. I could maybe alleviate this if I cone it before installation, then drill a short upward hole to hit it.   I may try this, but I need a die.  Does anyone know what 1/4-32 thread Chambers uses: UNEF, UNS, or UNF? I see all in the MSC catalog and I don't know the difference.  The tap Chambers sent just says 1/4-32. 

Another option to make the angled drill less critical, is to use a 5/16" plug, and I have a 5/16-24 drill and tap. But that only gives me 4 threads in the 3/16" barrel wall.  Is that enough, or would I be better off with 32 as Chambers uses, which would give me about 6? 

[Mike Brooks]

I think you'll find it will work fine the way it is.

[Whaleman]

I am not an expert at all. Could you add some weld metal on the top of the frizzen to cover the hole when closed? It would not need to be much. Dan

[Florida Jim]

1/4"X32 is "UNEF".

[moleeyes36]

What Mike Brooks said.

Mole Eyes

[smallpatch]

Listen to Mr Brooks.  All else considered, it will work fine as it is. 
These are not rocket parts.  Think you could have been that close 250 years ago with a hand brace?
Are you seeing half the drilled hole, or the finished touch hole?

[coopersdad]

I'm seeing at least half the drilled hole when the frizzen is closed.  It may work just fine, but it would drive me nuts every time I looked at it.  Guess I now have an excuse to do more on the lathe I'm trying to learn! 

[mossyhorn]

What Mike Brooks said, since he"s only made about 350 of these!

[David Rase]

I have a smoothbore built by Eric Kettenburg that has an external coned vent.  When the frizzen is closed, a portion of the cone is exposed above the pan cover.  I too was worried at first.  I shot the gun many times and it works just fine.  You should not have any problems.
David

[Mike Brooks]

What Mike Brooks said, since he"s only made about 350 of these!

That doesn't have much to do with it.....It's just that I have done the same thing the OP has...just didn't want to admit it is all..

[coopersdad]

Well I guess I'm in good company then.  I just need to learn to keep my mouth shut....    Thanks everyone for the replies!

[mossyhorn]

No we never learn until we ask and sometimes I DON'T LEARN WHEN I ASK!
Are is it I don't ask the right question the right way?  WHATEVER!!!!!

[coopersdad]

I apologize if I was misunderstood, it was a poor attempt to make a joke, and I have learned an incredible amount from everyone on this forum.  You're right, we don't learn unless we ask.  And I am indebted to all the other builders who've had issues and have asked questions here.  I was upset that I had really messed up, and to have people I greatly respect take time to answer me and allay my fears is wonderful. 

[EC121]

I'm confused.  When you say "drilled hole", are you seeing the threaded liner hole or the touch hole in the liner.  Either way it is OK.  I'm just confused.  I drilled one too low one time and had to grind the pan deeper so priming wouldn't cover the hole.  However it gave me an opportunity to widen the pan to catch more sparks.  That was before I read Pletcher's article about covered touch holes being faster.  Probably should have left it low.  Live and learn.   
     

[satwel]

FWIW the same thing happened to me on a smoothbore I was building. The vent ended up a little higher than planned. It has the fastest ignition of any flintlock I own.

[Turtle]

 I also had a smoothbore that had the vent hole partially exposed, and also experienced real fast ignition. When hunting in bad weather with it I just put a dap of window caulk over the hole with the frizzen closed. To fix it, why not install the next larger vent and offset the hole down? I have done this to move the touchhole location.
                                             Turtle

[bob in the woods]

I hesitated to answer this post, because I wasn't sure that my solution was " correct" .
I had the same problem on one gun I built, so I removed the frizzed from the lock, filed a bit off of the pan cover where it meets the barrel, and then soldered a "plate" or end piece on it. This covers the higher than normal vent , and also scrapes or wipes the area when operated. It also serves to enclose the priming powder.  I saw this done  in a publication some time ago, but can't remember where.

[coopersdad]

Sorry I wasn't clear - I could see the 1/16" touchhole itself when the frizzen is closed.  I'll probably use this as an opportunity to get better with the lathe and make a new liner and offset the touchhole a bit lower (and not stress out if the hole isn't exactly perfectly where I wanted it....).     Now that Bob in the Woods mentioned it, I think I've seen original frizzens with a lump on the top of the frizzen to cover the hole. 

[Mike Brooks]

Sorry I wasn't clear - I could see the 1/16" touchhole itself when the frizzen is closed.  I'll probably use this as an opportunity to get better with the lathe and make a new liner and offset the touchhole a bit lower (and not stress out if the hole isn't exactly perfectly where I wanted it....).     Now that Bob in the Woods mentioned it, I think I've seen original frizzens with a lump on the top of the frizzen to cover the hole. 

Vent holes are always better a bit too high than a bit too low. Nothing worse than a low vent, all kinds of slow ignition and hang fire problems.

[JCurtiss]

Vent holes are always better a bit too high than a bit too low. Nothing worse than a low vent, all kinds of slow ignition and hang fire problems.

That's the advice I've heard and read about too.

So I was surprised to read EC121's post about a Pletcher article saying that a covered vent hole is faster. 

[EC121]

Goes against what you would think, but if I read it right, his results say that.  I don't know about the hole being buried at the bottom of the pan.  That being said, I still like to see the hole above the powder.

[Daryl]

Vent holes are always better a bit too high than a bit too low. Nothing worse than a low vent, all kinds of slow ignition and hang fire problems.

That's the advice I've heard and read about too.

So I was surprised to read EC121's post about a Pletcher article saying that a covered vent hole is faster. 

Yes - powder covering the vent went faster in Pletch's timed events.

[Ridge]

The fastest lock I have has the hole almost on the bottom of the pan.  Anecdotal evidence, but all evidence starts somewhere.

My little 40 has the touch hole a bit too high.  You could sense just a slight delay in ignition until a gun builder I know coned the bottom half of the liner to funnel into the hole. That solved any problems I had.

[mossyhorn]

I always learn the most form my mistakes!!!!!!!!!!! 

[Boompa]

 Another, "Like Mike said".  Some of the hottest guns around have the vent hole just a tad high.