Wax cast trigger guard breaking

[bobw]

A friend called me yesterday and is fitting a wax cast Beck guard from Track to a gun he is building.  He needed to slightly bend it, so heated it to dull red and quench it in water.  As soon as he started bending it, it broke.  He has built several guns and has always quenched in water without issue.  Even though, I suggested not quenching it, which did, but it still broke.  I suggested while still red try bending it, still broke.  These test were tried on the already broken guard.. He called track and they told him he did everything correct, so told him to send it back to, them so they could see it.  He has a new one coming, but figures it will do the same thing.  Anyone else having this issue with wax castings? I’ve never had this, but don’t think I have ever tried bending wax cast parts.
Bob

[Eric Kettenburg]

If it's straight cartridge brass/yellow brass (260 alloy I believe) or something similar, quenching in water after heating to a dull red is perfect.  Most of the commercial investment castings are some kind of kryptonite bronze (I don't know the alloy) and I have never had good results with them by the same process.  If I have to use something like that, I heat it very dull red and shove it in a bucket of sand and let it slow cool.  That seems to work somewhat ok, they're still ridiculously tough and springy but you should be able to bend in careful increments without cracking or breaking.  The key with these is to bend in VERY slow, careful increments, not all at once.

[Hungry Horse]

 It’s probably because the trigger guard isn’t brass, it’s actually a bronze alloy, that is much more brittle than yellow brass.

Hungry Horse

[WKevinD]

I picked up a couple of inexpensive castings at Kempton last year. Smooth, great detail, but cheap $#@*. Looking at the breaks, on my annealed castings, they were crystalized brassish mystery material. I miss Reeves's castings and inventory.
Brooks has good brass and they take a lot of clean up...but they work.
Nice brass is now a luxury.

Kevin

[Carl Young]

so heated it to dull red and quench it in water.

"The annealing process is a heat-treatment method where brass is heated to a specific temperature, maintained for some time, and then slowly cooled"
https://shengenfab.com/how-to-brass-casting/

You can choose your method; I've been doing it this way about 50 years including industrial castings, and it works for me. Lots of info on the web from metallurgists who do this for a living.

Good luck,
Carl

[Jim Kibler]

Brass can be quenched from the annealing temperature with no adverse effects.

[Carl Young]

Not arguing with you Jim, just curious. Is there any advantage to quenching brass other than saving time? I usually leave my castings overnight then un-mold as I am not in a hurry.

Hope to get by your place again this year on the way to KRA.

Best regards,
Carl

[bobw]

Well, I was just curious if anyone else has had this issues.  I’ve never had problems annealing brass without any extended cool down, like what is needed with carbon steels.  It’s not like one can use these trigger guards as received, I’ve never seen where a guard doesn’t need at least a small amount of bending to fit a guns shape.  He said as soon as starting the bend, it would break, so wasn’t like a radical bend.  Track told him to send it back and they would replace it, but that’s probably just a rabbit hole unless the material is different. 
Bob

[Van]

  My question is does this apply to sand cast brass as well as wax cast?  I have bent my three sand cast trigger guards to the stocks with no heating and annealing at all without breaking. Just slow gentle curving around a section of steel pipe.  I was wondering if sand cast uses softer brass.   I have not had one that was wax cast.

[Bill Raby]

The commercial casting will get brittle if you quench them after annealing. If you air cool you won't have a problem.