Annealing wax castings

[draken]

How does one go about annealing wax cast "brass" ?

[Dennis Glazener]

If they are made from good alloy (like mine) they do not need to be annealed. Mine are so soft, as they come from the foundry, I believe you could tie one in a knot.

But the way work hardened brass is annealed is to heat it to a red heat then immediately plunge it into water.

Now some of the sand cast brass/bronze brass just can't be annealed. Believe me I know from trying too, then proceeding to break it in half trying to bend it!
Dennis

[draken]

Dennis, I am familiar with the characteristics of yellow brass and how to anneal it.   

The casting I'm inquiring about is a bronze/brass wax  butt plate.    I have it set into the stock and wanted to do a little gentle hammering on the edges to close up a few minor gaps.   Nothing major, but I know they are there.  I've done this before with sand cast butt plates.

What you are saying is that these hard wax castings cannot be annealed?   

I too, broke one of those several years ago.  Heated it cherry red and quenched it.  Wanted to flatten  it a bit and all was going well til it broke.   I assumed it broke from becoming work hardened.


Thanks for your input

[Dennis Glazener]

Dennis, I am familiar with the characteristics of yellow brass and how to anneal it.  

The casting I'm inquiring about is a bronze/brass wax  butt plate.    I have it set into the stock and wanted to do a little gentle hammering on the edges to close up a few minor gaps.   Nothing major, but I know they are there.  I've done this before with sand cast butt plates.

What you are saying is that these hard wax castings cannot be annealed?  

I too, broke one of those several years ago.  Heated it cherry red and quenched it.  Wanted to flatten  it a bit and all was going well til it broke.   I assumed it broke from becoming work hardened.


Thanks for your input
   

I don't think wax (investment) castings is the problem here. The problem is the alloy used in the casting process. All of the brass/bronze castings that I have used have been standard sand casting and not investment. I assume that some of the investment castings may use the brass/bronze alloy but I haven't seen any. Anyway, to the best of my knowledge you can not anneal that type alloy to make it pliable. If it can be I would love to know about it.
Dennis

[Dphariss]

Dennis, I am familiar with the characteristics of yellow brass and how to anneal it.  

The casting I'm inquiring about is a bronze/brass wax  butt plate.    I have it set into the stock and wanted to do a little gentle hammering on the edges to close up a few minor gaps.   Nothing major, but I know they are there.  I've done this before with sand cast butt plates.

What you are saying is that these hard wax castings cannot be annealed?  

I too, broke one of those several years ago.  Heated it cherry red and quenched it.  Wanted to flatten  it a bit and all was going well til it broke.   I assumed it broke from becoming work hardened.


Thanks for your input
   

I don't think wax (investment) castings is the problem here. The problem is the alloy used in the casting process. All of the brass/bronze castings that I have used have been standard sand casting and not investment. I assume that some of the investment castings may use the brass/bronze alloy but I haven't seen any. Anyway, to the best of my knowledge you can not anneal that type alloy to make it pliable. If it can be I would love to know about it.
Dennis

I have had one that would not anneal and bend. The color is slightly different as well. Has to be Bronze. It may be peanable but not much. Pretty hard stuff actually.
Major PITA.


Dan

[James]

Just a question, perhaps instead of annealing as with brass or silver, could it need to be annealed slowly like iron?

[Stophel]

Yeah, most of the investment cast "brass" is something other than regular brass.  It is usually somewhat grayish-yellow in color, unlike the nice yellow of "real brass".  I avoid it if at all possible, but sometimes you can only get a particular triggerguard shape in this type of stuff...

It is difficult, if not impossible to anneal.  It is springy, does NOT like to bend or form with a hammer, and is generally unpleasant to work with.  If lots of bending is required, heat and anneal it repeatedly, and HOPE that it doesnt break!

SOME investment casters do use real brass.  I have a "Marshall" buttplate from Chambers that is nice and malleable.  I have beat the $#@* out of it to make the "cupped" form of buttplate often seen on German guns, and will soon put it on a rifle I've been working on (slowly....)  I don't think I have annealed it even once....

[Swampwalker]

I've had some luck working the investment cast stuff, which I've been led to believe is bronze, while heated to a medium red heat.  Try it on a cut off sprue first, because if you try to work brass hot, it will simply shear off.

[mattdog]

What Dennis said.  It isn't the type of casting it is the material used.

I send waxes to the foundry and request "best yellow brass" and that's what I get.  It is malliable, can be annealed over and over, less likely to crack or crumble.  But is expensive.

The easiest way to determine if you are getting brass or an alloy (bronze) is by looking at the price.  I see some suppliers retailing heavy parts like butt plates and trigg. guards for less than I can make them using my own molds and casting my own wax.  I'm sure they are using less expensive alloys to be able to sell them at such low prices and still make a prifit.  I'm not saying they are bad, only beware when the price seems too good to be true.

Matt

[T*O*F]

In order to anneal something, you have to know what its properties are when it is in the annealed state.  If the material is of unknown composition, you may be peein" in the wind.  It could already be as soft as it's gonna get.  The act of heating a material red hot ain't gonna make it act like something it isn't, regardless of how much you want it to.

Also, quenching brass in water doesn't make it any softer.  That's an unnecessary step.  It just allows you to handle it quicker.  This myth came about from cartridge reloaders who want to only anneal the necks of their brass.  They submerge the case in water with only the neck showing, heat it red hot, and then tip it over into the water to cool it.  Thus it came about that unknowing people think it is necessar to quench brass.  It just ain't so.

[JCKelly]

By pass all the metallurgy (I am a retired metallurgist) and just buy all of your brass castings from Reeves Goehring, in Pennsylvania.

Reeves is a gentleman, and a knowledgable one. It is worth it just to deal with him. Prices competitive.

Nice soft ductile brass, for triggerguards & buttplates.

Or, you can buy Lord-knows-what castings from the major (and otherwise just fine) dealers in gun stuff.

[Old Ford2]

I've had some luck working the investment cast stuff, which I've been led to believe is bronze, while heated to a medium red heat.  Try it on a cut off sprue first, because if you try to work brass hot, it will simply shear off.

How do I know that???
Old Ford

[JCKelly]

Slightly off-topic, but - The reason one quenches brass after anneal, rather than cooling it slowly like iron/steel, is that many brass items contain lead. At the anneal temperature the lead, or much of it, is dissolved in the brass. If it cools slowly the lead precipitates (like, rain from clouds) as molten lead in the crystal (grain) boundaries. That weakens the piece. Quench it, and the lead simply does not have time to come out, stays in solution and the thing is reasonably ductile.

At least that's the theory. Used to be, in Ancient Times, that "brass" meant an ally of copper and zinc, whilst "bronze" was copper and tin. Lead was frequently present in either one. From mid-19th century on there arose about a zillion different copper alloys, with more-or-less arbitrary designations as "brass" or "bronze". One popular cast copper alloy is "silicon bronze". Silicon is cheap and it does make the molten metal flow well and fill the mold. The result is a hard alloy with a bit of a copper tint and a pretty hard casting. I personally do not know about annealing them.

Lead. Lead helps make a sound casting, which is why cast copper alloy plumbing fixtures all had some lead in them to prevent leaks. Until California banned that lead. One 1866 Winchester frame which I analyzed was a gunmetal (88%copper 10%zinc 2%tin) with about 1.5% lead which I presume was added for castability. The lead sure doesn't help the strength. 

Lead is why you do not attempt to heat brass for bending. At least not more than one try. That lead, which is usually if not always present, melts and makes the metal crumble when you try to bend it. Lead is in all brass bar to improve machinability, as well as in some or all brass sheet/plate, same reason.

Once again, I offer for your consideration that your gun-life will be smoother if you buy all your castings from Reaves Goehring. He and his ?son son-in-law? just bought the foundry that had been suppling them with nice soft brass hardware and some not-so-soft silicon bronze 'hawks. Dunno if there is any lead in his soft brass, I personally don't heat brass to bend it, period.

[mattdog]

Thank you JCKelly.  I think I just learned something.  

[Dphariss]

I did a bunch of hammering on a Goehring #10 buttplate to reshape it and annealed it several times to avoid cracking it but I would not form brass while hot either. If its really brass it will be soft enough after annealing.
This casting was wonderfully malleable until I beat on it some...
Dan