Kentucky rifle trigger guard problem.

[greymount]

I am in the process of building a Pedersoli Kentucky rifle kit in 50 caliber. While attempting to bend the trigger guard to obtain the correct fit with the inletted areas the guard broke in half at the front screw. I ordered a replacement trigger guard from Dixie and while attempting to bend that piece, it broke off at the rear screw. Boy is that foreign brass brittle. Is there any way the guard could be repaired at the break area or do I have to order another for $27.00. Would expoxy or some other material work in in putting the guard back together. Has anyone fixed similar problems with broken brass.

 

[Zonie]

The problem your having has to do with the Brass alloy and the way it was cooled when it was cast.

Brass (and especially Bronze) castings are brittle, and will often break if they are bent very much.
If you need to bend the brass/bronze casting, you first have to anneal it.

To anneal it you must heat it up until it is "bright red" hot.
After it reaches this color, immediately plunge it into a bucket of cold water. This will soften the material so it can be easily bent.
(Yes, it is just the opposite of annealing steel).

Another thing about Brass/Bronze. They both "work harden". This means, if they are repeatably bent in the same area, they will get hard (and brittle). If that happens, and the material wants to "spring back" to it's former shape, it may have to be annealed again.

 

[shunka]

Howdy Greymount -
Regarding a repair - the best bet would be to hold the pieces in alignment in some kind of fixture, and use brass brazing rod and a torch of sufficient heat to braze them back together. This is kind of like gas welding, but using brass. Once brazed back together, anneal the piece as Zonie relates above. If you are willing to make the investment, you can pick up a BernzoMatic Oxy Propane torch at Home Depot, Lowes or Ace for ~ $40. it includes some sample rods which includes aluminum, brass, steel, and nickel-silver bronze.

You'll find this baby torch doesn't have enough oomph to cut, and it eats up the $7 Oxy tanks like the dickens, but it does a great job of brass and nickle-silver brazing on just about anything brass or steel. I have become a great proponant of nickle-silver brazing, as it has a very nice silvery finish and I have found that a mild steel weld joint has a tensile strength of 45,000 psi, and a nickel-silver bronze brazed joint has a tensile strenght of 85,000 psi!

Oh yeah, and don't even think about using it on silver - I ate up a chunck of sterling bolo backing before I could move the point of the flame .. ::
good luck and best
shunka

 

[crockett]

Nickel-silver brazing. For $40.00 that seems like a really good deal, especially for putting pipes on underribs, etc. I snapped an entry pipe and that would have solved the problem. What's involved with silver brazing? Do you need flux, etc, and how much heat is produced? I have looked at some sets with map(?) gas and an oxygen bottle. Is that what you are talking about? Do you use regular rods(silver brazing)? On the brass trigger guard, how much would the joint show?

 

[shunka]

the torch to which I am refering is the OxyMapp torch found here:
Bernzomatic Web Page

For the brass triggerguard I would recommend yellow bronze brazing rod - it melts ~ 1600 deg F and it should match the brassy color=
Bronze Brazing Rods

But you might also try the more coppery Phosphor Copper Rods which melts at only 1450 Deg F.

The Nickle Silver Brazing Rod has a shiny silvery color, and would not match well- it melts at about 1750 deg F.

All of these rods are flux coated, but I like to clean the surfaces with very fine emery paper or 0000 steel wool, then treat with a common acid flux first. The entire purpose of flux is to keep the metal surface from oxidising as it heats; the oxidation makes a barrier against a clean solder, braze or weld joint.

Silver Solder, another common joint method needs only ~ 800 to 1000 deg F. Silver Solder can be found at most hardware stores or walmart, common lead free silver solder is an alloy of 4% silver and 96% tin, makes a reasonably strong lower temp joint, but leaves a silvery joint that will really show.

good luck and
best regards
shunka