Author Topic: Lengthening a sear arm with no welder  (Read 862 times)

Online rich pierce

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Lengthening a sear arm with no welder
« on: April 30, 2024, 02:34:44 AM »
Sets of lock castings bring all sorts of unexpected challenges because they copy originals, without considering whether the lock as it is cast will work well in a variety of situations. In this case, after assembling my new build I found the sear arm was short enough that it did not pass beyond the trigger plate. Not sure why I hadn’t noticed that. Seemed to work during the build but maybe just barely.

So I made a lap joint extension with a piece of 1080 steel, pinned with a 1/16” rivet, wrapped it tight with tie wire, and brazed it using propane torch and a brick cubby. I figured this might be suitable for a period repair. There was not enough extra material to draw it out, and welding something this tiny in a forge seems risky. I wait till the braze has run, allow to cool,  and file and polish. Then I re-harden and quench as the hardening temp is less than braze flow heat. Then I temper to 450 in sand-filled can for an hour. You can see the braze joint after cleanup, hardening, and quench better.









« Last Edit: April 30, 2024, 02:45:56 AM by rich pierce »
Andover, Vermont

Online smylee grouch

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Re: Lengthening a sear arm with no welder
« Reply #1 on: April 30, 2024, 02:51:25 AM »
Neat work Rich.  ;)  :)

Offline alhedrick

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Re: Lengthening a sear arm with no welder
« Reply #2 on: April 30, 2024, 03:00:19 AM »
have same issue on a sear for a cva guy took a spill and broke stock and sear and trigger gaurd

Offline Bob Gerard

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Re: Lengthening a sear arm with no welder
« Reply #3 on: April 30, 2024, 03:05:45 AM »
Rich it’s always fascinating to see what you can do.

Offline smallpatch

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Re: Lengthening a sear arm with no welder
« Reply #4 on: April 30, 2024, 05:40:38 AM »
Nice job Rich!
In His grip,

Dane

Offline Dave B

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Re: Lengthening a sear arm with no welder
« Reply #5 on: April 30, 2024, 06:41:57 AM »
Well done Rich, it will get the job done and if you heat sinked the sear you wont have to  worry about loosing the sear loosing its temper...... un like my redheaded wife used to.... ;)
Dave Blaisdell

Offline Daryl

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Re: Lengthening a sear arm with no welder
« Reply #6 on: April 30, 2024, 06:46:52 AM »
Good idea, Rich - good job. ;D
Daryl

"a gun without hammers is like a spaniel without ears" King George V

Offline Curtis

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Re: Lengthening a sear arm with no welder
« Reply #7 on: April 30, 2024, 06:56:14 AM »
Awesome save, Rich!  Well done.


Curtis
Curtis Allinson
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Sometimes, late at night when I am alone in the inner sanctum of my workshop and no one else can see, I sand things using only my fingers for backing

Offline JTR

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Re: Lengthening a sear arm with no welder
« Reply #8 on: April 30, 2024, 06:19:24 PM »
Looks good to me!
John Robbins

Offline Craig Wilcox

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Re: Lengthening a sear arm with no welder
« Reply #9 on: May 01, 2024, 01:36:54 AM »
One certainly does get a great education on this amazing forum!  Thanks Richard.
Craig Wilcox
We are all elated when Dame Fortune smiles at us, but remember that she is always closely followed by her daughter, Miss Fortune.

Offline taterbug

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Re: Lengthening a sear arm with no welder
« Reply #10 on: May 01, 2024, 03:35:40 PM »
Nicely done!  Definitely something I hope I can remember if (when) I need it.

Offline Dphariss

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Re: Lengthening a sear arm with no welder
« Reply #11 on: May 01, 2024, 04:09:40 PM »
Nice work. I have seen a complex, multi pieces added, brazed part from the late 19th c that were then casehardened in colors. So brazing is a valid way to add to or fix parts that are then to be hardened.
He who dares not offend cannot be honest. Thomas Paine

Offline P.W.Berkuta

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Re: Lengthening a sear arm with no welder
« Reply #12 on: May 01, 2024, 06:33:31 PM »
The key to that brazed joint is the rivet ;)
"The person who says it cannot be done should not interrupt the person who is doing it." - Chinese proverb

Online rich pierce

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Re: Lengthening a sear arm with no welder
« Reply #13 on: May 01, 2024, 09:07:38 PM »
The key to that brazed joint is the rivet ;)

Yep. Plenty of bad experiences where things wriggled around during the heat!
Andover, Vermont

Offline WKevinD

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Re: Lengthening a sear arm with no welder
« Reply #14 on: May 01, 2024, 11:40:55 PM »
Rich, timing for this couldn't have been better. I was just using a Chambers "Gunbuilders Lock" to restore an 8 gauge fowler with a wide breech and needed an extra 1/8" to hit the trigger. Thanks!

Kevin
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