Weld repair hrdness

[Tonyd]

Am probably going to have to get a friend to weld up a cracked tang and then have to re-drill the bolt hole. Will the weld spot be super hard as a result and if so how to drill it--use diamond type bit or anneal it first and then use regular hi-speed steel drill? Annealing is sone by heating to red hot and letting cool at room temp?

The tang and breech plug will be OK to use after annealing to drill if that is what I have to do??

Tony in SEattle

 

[Bill Hall]

Tony, yes, welds tend to be a little harder than the metal around it. When welding mild steal, like a tang, and using a mild steel filler, it's not much of a problem. File the weld flush with the parent metal, then make a good center punch mark, use a sharp bit, and you shouldn't notice a difference.
As far as anealing, when your friend finishes welding, just set it aside and let it cool. You don't need to aneal steel unless it was heat treated to begin with.

 

[davy]

From what I heard .. proper annealing of steel - is taking metal to a proper red heat, and then cooled SLOWLY by putting said red hot object in something to slow dome the cooling period ... such as ashes, sand, or vermiculite!

I would weld it up & then do this ... :thumbsup:

Davy

 

[WRussell]

You tend to get slag/scale on the surface, and that can mess up a good file. Diamond files (the cheap hobbyist grade) are great for this.

 

[Birddog6]

Should not be a problem if ya use a wire welder. I have done lots of them with no issues. Weld it up, grind it close to what ya need, then file it. When ya weld it do Not quench it, let it slowly cool. When I weld one I do a little at a time as not to get it real hot.

:thumbsup:

 

[eelclam]

An item suck as a tang I would weld on the under side first because that is the side that a crack has the most chance of starting. The area of the crack will be work hardened and the welding will aneal it. I would bevel the crack weld the under side and bevel a groove across the crack on top and fill that with weld. Tig welding is the best for this, no slag and much greater control than mig. It should be a solid metal full penetration weld. If it can be reprofiled with out bending it then it would not be necisary to aneal it but if you need to bend it to fit more than a little it would aneal it. As some one said above red heat slow cooling. Thats hard in small part the cool fast so you can take a red heat and put it in a hot oven and drop the temp slowly.

 

[eelclam]

sorry for the typo and i do realize the barrel probably won't fit in the oven

 

[Zonie]

Assuming this is a fairly new part I can feel confident in saying it is made out of "mild steel".

This type of steel doesn't have enough carbon in it to harden, and even if it did, if the part was left to air cool after welding it wouldn't harden.

I would suggest to the welder that he "build up" the area a little while he/she is welding it.
This will add a little more material to the surfaces.

I once had a tang welded back on to a plug and although the weld was successful the welder didn't build up the area. After I was done filing it back to match the adjacent surfaces there were a couple of small pits left on the surface.

zonie

 

[peashooterJoe]

Don't feel bad Zonie, I had a guy tell me it was character marks. They was expensive character marks by a supposed professional, if you know what I mean. Couldn't take a chance to redo it, was an original vincent barrel tang.
You shouldn't have any problems, just heed the advice from the fellows above.

 

[ricklandes]

I can't tell if you tang was already inletted in the stock or not. If it is not cut it off and reweld a suitable piece of flat stock, hot or cold roll is fine. TIG it on or have it done. It needs to be spotted on each side and then welded 100%. Do not be concerned with hardening and the like. It is a mote point. The filler rod is just a standard filler nothing fancy. Most will file down fine for your application. If it is inletted small "dots" of TIG can be done that will repair the crack. However, I would want to know why it happened so as to prevent future problems.

I buggered a tang up one time...could not get the exact shape in my head on to the metal, despite my template guidelines. It was rewelded twice and it was fine.

(It sure doesn't hurt either that my business partner/friend is a NASA certified welder for our shop either.)

:grin: Or for fun you could try the old forge with some sand, iron fillings and borax as flux and weld it the ol' way NOT!!!

 

[ricklandes]

I find it very "bothersome" that a welder would say that to you. He should know that by watching his puddle carefully, with the right heat that those gas out pockets will not be there. I hope you do not have to go back ever to him!!!