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View Full Version : Citric acid bath -- some red, how bad is it?



patsher
04-12-2011, 11:58 AM
Could someone please clarify how to judge whether to discard 9mm cases which are still red after tumbling (following cleaning in citric acid bath)?

I've been very picky so far, pulling even those which have a pinkish cast to them, but I'm getting so many like that, I'm beginning to think some of these may be okay to continue shooting.

What are the criteria for pulling them out of service?

Thanks!

Pat


Here's the link to the original discussion: http://castboolits.gunloads.com/showthread.php?t=83572

AggieEE
04-12-2011, 01:21 PM
patsher; I think you are leaving the brass in too long or you have too strong of a citric acid solution. Another thought how are you tumbling them? If you have fresh ( relative term I use mine till it dies) media with polishing compound in good condiction it should remove all of the surface copper that the citric acid exposes. I don't think the red color is in itself is a problem it is when you get the brass too thin from etching. If you don't leave them too long or have too strong of a solution I would think that you would loose the brass first or have mouth cracks before you would have a problem. Just my .02 and worth that maybe.
AggieEE

geargnasher
04-12-2011, 01:39 PM
I disagree that you're leaving them in too long. You WANT the tarnish "reduced" from oxide back to elemental metal. The citric acid pacifies the remaining base metal and slows the rate at which it will re-oxidize, unless you polish off the thin passivated layer with your tumbler. One of the great attributes of citric acid is it won't damage the brass, you can leave it in the solution for hours and once the brass gets to a certain point, it stabilizes.

My criterion for discarding pink brass is if the spots don't polish off within 30 minutes in the tumbler with abrasive cob media. Usually, the pink is gone in 15 minutes with untreaded cob pet bedding if it's light.

The other thing to look for as definite discard criteria is pitting in the copper areas visible after tumbling, check it with a hand lens or loupe and bright light, if you see ANY pits discard the brass. Once the zinc is depleted from the copper leaving copper-colored patches that won't polish off easily and quickly in the tumbler or depleted enough to leave pits behind, scrap the brass. Imagine little termites eating out the zinc, leaving soft copper that's perforated like Swiss cheese, that's what happens when the zinc oxidizes out of the brass, and its not good for high-pressure cartridge brass. Remember, if the brass fails, the chamber fails and you get a Kaboom.

Gear

mold maker
04-12-2011, 02:55 PM
I had never paid close attention before, but after annealing 9mm brass for swaging, I cleaned it in strong very hot citric acid. I was in a hurry so I dried and placed them in the tumbler. After over night in the 50/50 cob/walnut media, I had beautiful brass to swage. About 8/100 were brightly polished copper cases. They weren't spotted, or pitted. Just like the brass, they were bright and smooth. I'll have to wait till tomorrow to look, but I'll bet their all the same brand.
They will make some fine looking .41 cal (copper) JHP. Except for the rim, they will look exactly like factory.

jcwit
04-12-2011, 04:57 PM
Just tried the All Purpose Cleaner with the listing of Rust, Lime, Calcium put out by LA's Totally Awesome and sold by Dollar Tree. Someone else had a thread about this stuff here and yes it does work.

Man alive, a couple of minutes in that stuff which was diluted 50/50 with hot water sure brought back the orginal brass color to brass with no pink color.

MtGun44
04-12-2011, 09:09 PM
The pink color is due to dezincification of the surface brass during the corrosion process. The
zinc (30% of cartridge brass) is more easily converted to oxide and removed during corrosion,
especially out of doors when wet. When you reverse the oxidation process with citric acid,
the copper oxide (the dark brown extreme brass tarnish is pretty much straight copper oxide)
reverts to pure copper, which is pinkish since the zinc is gone. For low pressure brass like
9mm and moderate amounts of dezincification, especially if it is uniform, I would not worry
about it. Rifle ammo with small areas of intense local corrosion may be problematic due to
the local nature and much higher working pressures. But if no significant material is missing,
it is probably nothing to sweat. I have no doubt that the brass that is pinkish was the very
dark brown extreme tarnish.

I expect that the All Purpose Cleaner is just etching off the surface rather than reversing
the oxidation process, so no pink, but some material removal and possibly some short term
and maybe even long term damage. Unless I knew EXACTLY what is in some solution, there
is no way I would put my brass into it. For example, exposure to even low levels of ammonia
over time will cause serious stress corrosion cracking of brass. I have seen a batch of
older 7x57 brass made in WW2 by FN (guessing Belgium) that has 100% cracked necks. Probably
from ammonia contact. I always wondered if some heroic Belgian ammo plant worker was
sabotaging Nazi controlled ammo production by peeing on some of the packing material,
which would cause cracking long after passing the initial quality checks so the workers would
not be suspected of sabotage, but the ammo would be unreliable since the bullets were loose.

Bill

jcwit
04-12-2011, 10:04 PM
Benefits

• No acid
• No ammonia
• No bleach
• Non-flammable
• Safe for septic tanks
• Contains no phosphorous
• Made in the USA


There you go should put your mind at ease. It was copies from their web site.

http://www.lastotallyawesome.com/

Gonna leave my misspelling as it is, looks and sounds like a poor chinese translation. hehehehe

geargnasher
04-13-2011, 12:33 AM
The pink color is due to dezincification of the surface brass during the corrosion process. The
zinc (30% of cartridge brass) is more easily converted to oxide and removed during corrosion,
especially out of doors when wet. When you reverse the oxidation process with citric acid,
the copper oxide (the dark brown extreme brass tarnish is pretty much straight copper oxide)
reverts to pure copper, which is pinkish since the zinc is gone. For low pressure brass like
9mm and moderate amounts of dezincification, especially if it is uniform, I would not worry
about it. Rifle ammo with small areas of intense local corrosion may be problematic due to
the local nature and much higher working pressures. But if no significant material is missing,
it is probably nothing to sweat. I have no doubt that the brass that is pinkish was the very
dark brown extreme tarnish.

I expect that the All Purpose Cleaner is just etching off the surface rather than reversing
the oxidation process, so no pink, but some material removal and possibly some short term
and maybe even long term damage. Unless I knew EXACTLY what is in some solution, there
is no way I would put my brass into it. For example, exposure to even low levels of ammonia
over time will cause serious stress corrosion cracking of brass. I have seen a batch of
older 7x57 brass made in WW2 by FN (guessing Belgium) that has 100% cracked necks. Probably
from ammonia contact. I always wondered if some hreoic Belgian ammo plant worker was
sabotaging Nazi controlled ammo production by peeing on some of the packing material,
which would cause cracking long after passing the initial quality checks so the workers would
not be suspected of sabotage, but the ammo would be unreliable since the bullets were loose.

Bill

Good explanation, Bill, thanks. I would argue, however, that the 9mm is anything BUT a "low pressure". Standard pressure 9mm equals .357 Magnum, .40 S&W, and .44 Magnum pressure levels. While it might not be a .300 Winchester Magnum, it is 2-1/2 times standard .45 Colt pressures and 1-1/2 times .45 ACP pressures, and partially unsupported chambers add to the stress on the brass if loaded to full potential. Everything is relative, I guess, but as cheap as 9mm is it doesn't pay to use iffy brass IHMO. Now .45 ACP, if it will hold a primer and a boolit and has some semblance of a rim left, I shoot it.

Gear

MtGun44
04-13-2011, 01:36 PM
Comparing 9mm to rifle pressures, it is low. Comparing to some other pistol cartridges, you
are right it is on the high end, esp with +P class loads.

Still, a relatively uniform loss of some zinc on the outer .00001" of a brass case is not something
to be concerned about. A concentrated small area of corrosion may have some intergranular
penetration that is not visible and may be dangerous, especially with full power rifle loads
at about 60,000 psi. Spot corrosion that appears to be intense would seem to lead the
prudent user to recycle it.

I'm sticking to citric acid, but it is a free country (to some extent) and others are welcome
to experiment with their own brass.

Bill

jcwit
04-14-2011, 08:20 AM
Well after reading more posts regarding the LA Awesome cleaner and what it says about brass I'll retract the recommendation of using it on brass. At least it can be used as a coffee maker cleaner and other uses in the kitchen and bathroom.

Glad I did a little more looking and closer reading.

olafhardt
04-14-2011, 05:09 PM
Copper and zinc compounds are toxic to the bacteria that make a septic system work in levels as low as 5ppm. You may not want to dump your brass cleaning residues dowin the drain.

felix
04-14-2011, 05:35 PM
5ppm is not very low, in fact, quite high for many organisms. 2ppm is plenty to kill the majority of stuff in my swimming pool over winter, and must be lowered to 0.5PPM before swimming to be entirely safe. ... felix

W.R.Buchanan
04-14-2011, 06:18 PM
I occasionally use Lemishine dishwasher soap to clean brass. But I am only interested in getting the majority of the dirt off the cases.

I tumble my brass (no matter what caliber) for 24 hours in a Thumblers Vibratory Tumbler with Walnut hulls (bought from Petco) and Dillion polish. I have been using the same batch of media for the last 8 months, and have ran probably 50 batches of brass thru it. 250-300rnds. per batch for pistol, 150-200 rifle.

After 24 hours there is usually no discoloration of any kind either on the outside or the inside of the cases. Also they remain looking like that for over a year when exposed to the normal air in my shop. So the Dillion spuge is pretty good at protecting the finish of the brass after it is tumbled.

I have seen a few cases with the copper colored stains after the Lemishine, but never do the stains survive 24hrs in the tumbler.

I see alot of guys here that are affraid to run their tumblers for very long. These machines are made to be ran continuously. When tumbling rocks for a polished finish the machines have to run for literally weeeks at a time. Typically you will go one week, and then change to a finer grit media, and so on until you achieve the polish you are looking for.

My big vibro tumbler has a 3/4hp motor on it and I usually run it for 3 day runs to deburr and polish Stainless Steel and Titanium parts in my shop. The machine is designed to do this and just running it will not significantly decrease its service life. Now letting them sit idle will decrease their service lives, as dirt and corrosion are the 2 major enemies of machines. Both of which accumulate rapidly when sitting idle. I keep mine covered in the shop with an old bedsheet so they don't get covered with dirt.

I say you are better off tumbling more and using chemical cleaners less.

Randy

pls1911
04-14-2011, 06:27 PM
This thread has me concerned, and I appreciate some comment...
Veryquick, very dilute pool acid wash -- water rinse -- water/soda rinse -- dry -- tumble polish.
Many thousands 30-30, 45 colt & ACP, .38 special rounds at nominal/medium loads have been processed like this without failure for ..er.. too many years.
You chemists tell me... am I safe or just lucky?
Am I incrementally rendering visually good brass to an unsafe condition?
Thanks.

Paul

RP
04-14-2011, 06:37 PM
This brass is for swaging them these are 40 cal brass which be made into 44 cal bullets

I have tried the critic acid cleaner on brass that I have annealed. I have tried Jet Dry brand dishwasher agent and got some from a woman that makes wine. I also found some lemi shine I will be trying later as I need it. Here is a pic of some brass I annealed for swaging http://http://i244.photobucket.com/albums/gg31/Ricky1965/010.jpg
I dumped it into my pot of cleaner which was warming up while it was still hot or right out of the flames, It sat for about two mins top I mixed it around a little then removed. http://http://i244.photobucket.com/albums/gg31/Ricky1965/012.jpg
Now Iam using this brass for swaging not reloading. Dont know if was the citric acid I got from the wine lady I may have it to strong but for me works great for me. Have not tried it on brass I will be reloading.

MtGun44
04-14-2011, 08:59 PM
Fully annealing the whole case RUINS the brass and probably makes it unsafe to fire!!!!

You might get away with it at pistol pressures but you can blow a rifle up with this VERY
dangerous move. You MIGHT manage to get the temp right for a partial anneal and MAYBE
not soften the case head enough to cause a failure, but it would require a lot of precise knowledge
of the annealing temps of brass and exactly what temp you exposed the brass to. Annealing
the whole case is a very unsafe practice.

I will go as far as saying that if you fully anneal rifle brass a full power load will almost
guarantee to blow out.

Brass ONLY hardens during permanent deformation such as when the raw brass is punched
to shape and extruded. When you heat it up to anneal the whole case you remove the
work hardening in the case head area so that it is now not as strong as the manufacturer
intended. There is NO WAY to recover the lost hardness in the case head area because the
amount of working ( permanent deformation) needed is too much to get with any reasonable
amount of deformation.

You CAN recover from excessive annealing of a case mouth ONLY in brass by expanding, then
resizing, then expanding, and resizing repeatedly to work harden the neck. This work hardening
is why we need to anneal rifle brass and occasionally some pistol brass, but NOT THE WHOLE
CASE!!

For wadcutter .38 Spl loads or similar VERY low pressue loads, and if fully supported like in
a revolver, fully annealed cases MIGHT be OK, but will probably not hold a primer securely
after one or two firings. In a semiauto, most guns have a portion of the case unsupported and
this is likely to blow out on firing, esp with stuff like the very high pressure .40 S&W, which
the example cases appear to be.

IMO, brass that has been fully annealed like the picture is scrap and I would not use it
for any loading purpose.

As to the mild, short acid wash. I doubt that you have damaged the brass, but I would not
recommend this as a normal process. Thorough, rapid rinsing to prevent localized residual corrosion is
likely prevent problems. Citric acid is far safer.

Bill

olafhardt
04-14-2011, 09:48 PM
I Don't clean it I just reload it and shoot it. What is this cleaning stuf.

MtGun44
04-14-2011, 09:49 PM
Olaf - works fine, don't sweat it.

Bill

olafhardt
04-14-2011, 09:55 PM
Anal retentives are everywhere even here.

btroj
04-14-2011, 09:59 PM
Bill, I think he fully annealed the cases to use for swaging into bullet jackets. He doesn't intend to load them if I follow his post correctly.
You are, however, entirely correct about annealing the entire case. Very dangerous. You brought up a good point with the number of newbies here. They need to understand that bullet swaging is a different ball of wax from ammo loading.

geargnasher
04-14-2011, 10:06 PM
Bill, I think he fully annealed the cases to use for swaging into bullet jackets. He doesn't intend to load them if I follow his post correctly.
You are, however, entirely correct about annealing the entire case. Very dangerous. You brought up a good point with the number of newbies here. They need to understand that bullet swaging is a different ball of wax from ammo loading.

+1, say it louder.

Gear

MtGun44
04-14-2011, 10:22 PM
WHEW!!

OK, great to hear that he wasn't just confused on annealing and discovered
"a better way" !!!

Do that with a rifle case and you are likely to turn a good gun into shrapnel.

Bill

243winxb
04-15-2011, 09:31 AM
Reclaimed range brass- Ammonia forms in nature from rotting vegetation and moisture. The ammonia will attack cartridge brass causing stress corrosion cracking. MtGun44 covered it well. :)

Cap'n Morgan
04-15-2011, 11:42 AM
I have seen a batch of
older 7x57 brass made in WW2 by FN (guessing Belgium) that has 100% cracked necks. Probably
from ammonia contact. I always wondered if some heroic Belgian ammo plant worker was
sabotaging Nazi controlled ammo production by peeing on some of the packing material,
which would cause cracking long after passing the initial quality checks so the workers would
not be suspected of sabotage, but the ammo would be unreliable since the bullets were loose.

Maybe the FN ammo factory shrimped on the copper in their alloy or skipped an annealing process.

A friend of mine once stumbled over large batch of old FN 9mm ammo made in the fifties. Maybe one in three had a split neck, but still seemed to grip the bullets quite well. We were young and poor back then and used the lot up without any problems.

Boerrancher
04-15-2011, 12:13 PM
I very seldom tumble my pistol brass, and never anneal it. when the mouth of the case starts to crack I toss it. I tumble my large rifle cases, 60 gr water wt capacity or larger, and will at times anneal the neck and shoulder area of some of my wild cats and large magnums do to the cost of brass.

Stuff like 30/30 and 223 Rem, that I pick up around the range, I don't even bother except to tumble them the first time to clean the range grit off of them. The is the first and last time they see the inside of my tumbler.

Best wishes from the Boer Ranch,

Joe

RP
04-15-2011, 12:24 PM
I you read my post you will see that I said I was using this Brass to swage with making 40 cal brass into 44 cal bullets. But I can see the confusion and will go back and edit the post to make it clearer for everyone.

RP
04-15-2011, 12:30 PM
I also agree about the new people here getting confused about whats whats I know I still do. Easy to get confused on things you are learning about thats why its so important to check double check and confirm something before you do it.

mold maker
04-15-2011, 01:04 PM
I you read my post you will see that I said I was using this Brass to swage with making 40 cal brass into 44 cal bullets. But I can see the confusion and will go back and edit the post to make it clearer for everyone.

I do the same, with the same equipment, and with the same results. Boy do they make some impressive 44 boolits.
Also starting to turn 9mm cases into 41. The 9mm cases that came out of the tumbler completely copper were all the same brand, and the finished .41 loaded ammo looked factory.
Thanks to BT Sniper, I will never buy .41 or .44 JHP again. The dies have already paid for themselves, cause I'm using only free range lead and brass to feed my habit.

RP
04-15-2011, 07:14 PM
I see your in NC also Iam near Goldsboro largest town near me I dont know where Conover is. How close are you to me I am having some minor problems with my swageing getting fill out in the brass BT is helping me figure it out but someone to show or seeing it helps alot.

MtGun44
04-16-2011, 12:02 PM
Ramrod - sorry to misunderstand the purpose of the annealing. I do not do swaging bullets,
so was unfamiliar with the process. I saw the whole pan of pistol cases and thought that
somebody had misunderstood the whole annealing thing. I wanted to be sure that it
didn't wind up with a blown up gun and even somebody getting hurt.

I'll bet that the bases of the bullets are really TOUGH! Sounds like a neat idea, but then
again, I shoot 100% lead alloy and manage pretty well.

Be careful and enjoy the hobby.

Bill

snuffy
04-16-2011, 12:46 PM
Here's a twist for the flow of this thread. I was at a local gunshop a couple weeks back, he had the Hornady set-up for ultra-sonic cleaners. He had a jug of the concentrate for the US cleaner.

Since I already have a harbor freight US cleaner, I bought the concentrate. It is citric acid, I suspect there's also some sort of soap in it. Mix is 40-1 so I mixed up ¼ cup with 10 cups of hot water.

I had bought 500 never fired/new LC-09 .223 brass from Graf & sons. It arrived all water stained. Tumbling did nothing to remove the stains. I had read that citric acid would remove the stains. So, I loaded it up with 100 lc cases, turned on the heat, and ran it through 3 480 second cycles. It emerged without any staining!:p

I ran 2 more batches, same result, nice shiny cases, no stains. I had packed up my work locker recently after retiring. I had a shoe horn in there for when I changed to my work boots. It had a lot of rust on it. I tossed it in for a cycle, then forgot about it.

I discovered another 100 bag of the LC brass, tossed it in the US cleaner forgetting the shoe horn was still in there. Ran 3 cycles, took a look at the brass. It looked like this;

http://photos.imageevent.com/jptowns/cannont2ifolder/websize/IMG_0319.JPG

The brass that was close to the shoe horn, or in contact with it, was totally copper colored. Some of it had a black sludge on it. The shoe horn was completely covered with that black stuff. The rust was gone, it appeared to be bare steel with traces of copper on it. I think it was chrome plated at one time, so the copper was a base coat for that.

http://photos.imageevent.com/jptowns/cannont2ifolder/websize/IMG_0327.JPG

The copper surface on the affected brass is extremely thin. It is easily removed with steel wool, it could be tumbled off.

I ran this story on several reloading forums TFL, THR, the consensus of opinion was it was a galvanic reaction between the steel and the zinc in the brass, leaving copper behind. And that black stuff was oxidized zinc. Heat helped the reaction as well as the acid bath.

So, it's very possible to leach the zinc out of brass if the conditions are right. Look at this galvanic chart explaining the reactive relations of different metals.

http://www.grabberman.com/Media/TechnicalData/127.pdf

geargnasher
04-16-2011, 02:44 PM
Galvanic activity is interesting.

For years (87-95) Chevrolet ran throttle-body fuel injection systems on their 4.3, 5.0,5.7, and 7.4L engines, and the computer grounds were all attached to a stud-bolt on the thermostat housing. The housing and intake manifold was made of aluminum alloy, the thermostat brass or stainless steel, the stud of course was steel, and the engine block low-nickel cast iron. When Joe Owner does a cooling system drain/fill and puts the wrong coolant back in, then mixes it with hard tap water, what do you have? A battery. Dissimilar metals a Hot, conductive liquid flowing through it all, equals voltage potential. Up to four volts. So you connect a GROUND wire to a secondary "battery" which is already grounded to the primary storage battery through the negative cable, and instead of 13.8 volts going through the computer and to ground, you have 9.8 volts going to ground because it's connected to what is in effect the positive terminal of the thermostat housing "battery". I solved many computer-related engine performance issues by moving that ground to a different location, since the countering voltage would play hoc with sensor values seen by the computer, and you could tell a big difference looking at sensor readings with a scan tool after the repair.

Gear

MtGun44
04-16-2011, 05:29 PM
Gear,

That is hilarious! Recalibrating your entire engine management computer system by
changing the coolant. Gotta laugh at that one. Galvanic corrosion is a serious issue
and can cause lots of serious problems since it can, in some cases, be highly concentrated
as to location.

Snuffy - mixing metals in an electrolyte bath like that can get you all sort of odd reactions,
based on the position of the various metals in the electromotive series. You can make
batteries and cause severe corrosion or start electroplating, depending on exactly
what you throw in together.

Bill