Aging Brass with Ammonia?

[t.caster]

I recently saw Mike Brooks mention aging brass with an ammonia method. Can anyone explain the process?
I've been using super blue for years, but I'm open to other ideas. I tried brass black, but didn't like it.

[msellers]

I have just hung my piece of brass above a quantity of ammonia in a glass jar with a lid. Used the lid to catch the string I hung piece with. Sealed and walked away, coming back every so often to check the progress. Rubbed back some areas with 0000 steel wool and repeated process to aid in the aging look of use. Doesn't seem to be a completely permanent fix doing it this way, but works well enough for me. Also, tend to crush some black powder in a tiny amount of ammonia to create a paste and rub that onto the brass to further age and create different texture on the piece.
Hope my ramblings and limited knowledge are of some help to you.
Mike

[t.caster]

Mike, I've been doing that for a couple of days now and no affect. Come to think of it, they (rr pipes) were polished on a cloth wheel polisher with a garnet polish compound. Maybe I need to rub them down with steel wool to take the polish off.

[msellers]

Mike, I've been doing that for a couple of days now and no affect. Come to think of it, they (rr pipes) were polished on a cloth wheel polisher with a garnet polish compound. Maybe I need to rub them down with steel wool to take the polish off.

Also maybe try heating the ammonia a little, have read of giys going that. Might also be an issue with the ammonia you are using. Most stores sell very dilute stuff. Guessing the garnet polishing compound is probably leaving a waxy coat on the parts as well.
Mike

[Ky-Flinter]

Seems like I heard aging brass with ammonia would make it brittle.  Anyone had problems with that?

-Ron

[Tuffluck]

Hi, Check out my post on an aging solution for brass, I've used this to match repair work on older pieces, works great.

[snapper]

Ammonia will cause stress corrosion cracking in brass.  For this to happen however the piece of brass will have to have stress in the metal, like forming of pipes, cold bending without subsequent stress relief annealing etc.

We did research on anhydrous ammonia cargo tanks and stress corrosion cracking.  We took hoop sections out a tank that was made in the 1960's and sent it to the Los Alamos National Laboratory.   Neutron diffraction was used and it determined that the stress from the welded seams on the cargo tank were the same on the old tank as it was on a new tank. 

Fleener

[Ky-Flinter]

Here's a thread from a while back on the topic.  https://americanlongrifles.org/forum/index.php?topic=49365

-Ron

[PIKELAKE]

I have been using ammonia for years and have pretty good results. You have to make sure the brass is real clean; I rub it down with alcohol. If the brass is not pure brass, it can develop cracks. You really have to keep an eye on it, especially trigger guards. I try to keep air from getting into my tub. I put a piece of saran over my container, then the lid. JZ

[JCKelly]

For a short while ammonia does a nice job of aging brass. Too much ammonia or soaking it too long and the brass will crack. Doesn't make the brass brittle, does crack it.

Jerry Kirklin lived nearby & a coupla decades ago said some of his brass thimbles cracked when he had them in a container held above some household ammonia. Hmm. Hadn't Kelly said something about that?
Yep, Jerry, yep.

Brasso did a fine job of polishing my ROTC buttons in college. Smells of ammonia.

Heard of someone adding Brasso to the tunbling mix cleaning his brass for reloading. Brass came out clean, bright, - and cracked.

Ether take care & don't have the ammonia around too long or find something else.

In my Most Humble Opinion, only.

[Mauser06]

I've done it once.   


I suspended the parts ABOVE the ammonia inside of a sealed container.

Google "ammonia fuming brass" might help.


I didn't have any issues with cracking or anything.   I did have a part NOT take no matter what I did.  I'm suspecting it was some alloy.   Parts were on a TC Hawken. Trigger guard wouldn't take. 


I actually didnt care for it.  Turned the parts a brown color. 

[smallpatch]

Tom,
Super blue is easier!

[t.caster]

Yah, forget AMMONIA! I will give the black powder wipe a try though.

Thanks to all!

Tom C

[DHS]

For a short while ammonia does a nice job of aging brass. Too much ammonia or soaking it too long and the brass will crack. Doesn't make the brass brittle, does crack it.

Jerry Kirklin lived nearby & a coupla decades ago said some of his brass thimbles cracked when he had them in a container held above some household ammonia. Hmm. Hadn't Kelly said something about that?
Yep, Jerry, yep.

Brasso did a fine job of polishing my ROTC buttons in college. Smells of ammonia.

Heard of someone adding Brasso to the tunbling mix cleaning his brass for reloading. Brass came out clean, bright, - and cracked.

Ether take care & don't have the ammonia around too long or find something else.

In my Most Humble Opinion, only.

I have used Brasso in the tumbler an have never had a problem with the result...cracking or otherwise. 

[hanshi]

I've used "cold blue" on brass quite a bit with great results.  The finish looks like the finish on my iron mounted SMR; pretty durable, too.

[Pukka Bundook]

Spinner,

Those threaded brass fittings are brittle anyway.
I have never even Heard of Fumed brass becoming brittle.   
Some mention soaking brass in ammonia. I can see no good coming of that, and no good reason either.
We fume oak and other woods, and I'd like someone to explain to me how fuming brass makes it brittle.
Brittle I have never run into...
Here to learn though.  :-)

[577SXS]

I used vinegar and salt in a bucket and had parts on wire rack above the vinegar. I close top of bucket with aluminum foil. After a couple hours parts have nice patina to them. Wash them off and put a little oil on them and you are done.

[rich pierce]

I had a guard rail crack after fuming. I was making a small adjustment by hand on a Reeves Goehring guard. So, it has happened at least once.

[snapper]

They used to make the p trap under sinks in brass, until they started breaking from people cleaning with ammonia.

Fleener

[Pukka Bundook]

Rich,

When I was down at the gun-making course in Bowling Green in 2003, My late pal Ron Ehlert went to adjust my trigger-guard very slightly, and it broke in two.  I just soldered it up.  Point being it hadn't been near ammonia, and still cracked.
They still make the under-sink fittings of brass up here....

Any reasons for fuming making brass brittle Gents?
Not soaking in anything, just fuming?
Jim Chambers once told me his way of fuming, and I've done it his way and no worries.

Vinegar etc will take the zinc out and make brass brittle, if soaked in it. same with most acids.

Best,
Richard.

[rich pierce]

Reeves’ castings could be twisted into a knot. Well known for that. Yes, I soldered it up.

[JCKelly]

Just for fun -

A 1942 metallurgy book (J. Dudley Jevons, The Metallurgy of Deep Drawing and Pressing, ©1942) states:
It is well known that the atmosphere in the vicinity of stables and farm yards is a very dangerous one for stressed brass, and in olden times a car garaged in farm buildings often exhibited many season-cracked brass parts. It is not such common knowledge that the urine of rodents and of some other animals—for example, cats—quickly produces season-cracking, and that many tons of cold-drawn brass have been ruined annually owing to the unwelcome attention of mice and rats in old warehouses. . .” 

For the youngsters here, automobiles used to have nickel-plated brass trim. Contemporary machines should fare well in your horse barn.

Jim K, your P.I.T.A. metallurgist

[Eric Kettenburg]

I use ammonia to age brass.  I will admit to once, in the dim an distant past, leaving the brass exposed to the ammonia fumes for far too long, and ending up with rammer pipes that I could literally crumble just by squeezing them.  Yes, it really happened!  I am very careful now.

JMHO, but I personally believe that nothing will *realistically* age brass like ammonia fumes.  Sure, lot's of different things will darken or otherwise change the color of brass.  However, t's been my experience that genuinely old brass looks different, even if someone tries to clean it a bit.  There seems to be a compositional change to the material itself over time and exposure to (I assume) atmospheric elements.  I don't know, I'm not a metallurgist or a chemist.  I just know that ammonia fumes will create a color and appearance that even when rubbed back, still maintains an 'old' color.  Most applied chemicals will surely color the brass, but rub on it a little bit and it looks new again. 

I will reinforce the wisdom that if you use the ammonia method, you better keep an eye on it and remove it about two shades lighter than what you want because it will actually darken a bit more once removed from the humid atmosphere.  I use a variety of sealed plastic containers, and alternately apply gentle heat (with a drop light aimed at the container) or remove from heat to allow condensation.

[t.caster]

Thank you gentlemen for all the wisdom and warnings! I will learn from both as I venture forward.

Tom C