Comments on: The Perils of Ultrasonic Cleaning — Some Advice on Bullet Seating

By: Jim

Jim — Thu, 24 Apr 2014 20:40:09 +0000

What is the cleaning solution?
If the cleaner does not contain the right brass-corrosion inhibitors or is of the wrong chemistry, the brass could be getting chemically etched. Check to see if the cleaner is labeled as that it is brass-safe. Some cleaners that are labeled “all metal safe” may not be.
If your brass comes out of the ultrasonic bath nice and shiny and does not tarnish quickly, your cleaner is probably OK. If the inside of the neck is also nice and shiny, tell us what you are using, for heaven’s sake!
Standard cartridge brass (C260) is made up of roughly 70% copper and 30% zinc. If one or both of these are etched (dissolved) out, you can get a rough surface. The surface will have a dull surface – not shiny.
Alkaline solutions tend to remove small pieces of zinc from the surface, making the surface rough. Sometimes, there are also chemical deposits on the brass.
Acid solutions also dissolve zinc, making the surface rough. I have seen this used to chemically roughen brass to get better brass/rubber adhesion.
Lots of other chemicals or mixtures of chemicals can cause problems. A very common one is triethanolamine (TEA). It is used as a rust inhibitor. It also attacks brass. TEA disolves copper, so much so that it makes a copper solution strong enough to be an algaecide. TEA also can lead to stress corrosion cracks when the brass is worked during firing and resizing.
Some cleaner solutions can oxidize the brass or deposit various chemicals. Most cleaners have numerous ingredients.
One way to find out if the problem is the cleaner bath itself is:
– Clean the brass as usual with the ultrasonic cleaner, the see if the inside surface of the neck is rough. Brand new brass may have a coating of corrosion inhibitor, so don’t test it first. Some of this coating could wash off into the cleaning bath, so run the tests on used brass first.
– Mechanically polish the neck using one of the above techniques. Do not use any kind of polishing chemicals. Rinse the neck with water.
– Run the brass back through the cleaner, leaving it in a bit longer than usual (to make the etching more visible). Rinse as usual. Repeating this step would be helpful.
– If everything looks OK, load and fire the brass with the polished necks. Clean them as usual and see if the neck looks like it got etched.
– You can try this test on new brass, but wait until you have performed the tests on used brass. If the new brass has been coated with a brass-corrosion-inhibitor, it might end up in the cleaner solution and screw up the tests. If on the other hand, enough of the corrosion inhibitor dissolves into the cleaner bath … your problem may be solved.
If the neck still looks smooth and shiny after all this, your cleaner is probably ok. You might want to repeat this test a few times, just in case. If everything is still OK, please write a comment to tell me that I am a know-nothing-Bozo (I am married, so I am used to it).
Jim

By: Wolfdawg

Wolfdawg — Thu, 24 Apr 2014 15:42:28 +0000

So, if you use the Necos molly 9or other dry lube), what happens when you add powder? some of the molly/lube mixes in the powder. Some cases pick up more molly/lube than others which in turn ends up in the powder charge.
Just a thought…

By: brians356

brians356 — Wed, 23 Apr 2014 22:56:28 +0000

I agree with Kris that they’re not too clean. If dry moly helps, it is because it is lubing over rough brass which could be permanently smoothed by burnishing with 0000 steel wool. Likewise, this will also burnish away the sharp edge left by the chamfering tool on the inside corner of the case mouth. Having said all that, if dry moly helps, it might be easiest to simply not clean the powder soot out of the inside of the neck at all.

By: Kris

Kris — Wed, 23 Apr 2014 14:06:57 +0000

I probably should have proof read that before hitting submit…

By: Kris

Kris — Wed, 23 Apr 2014 14:04:54 +0000

That would be because the SS tumbling removes the oxide layer. Try running a bronze brush (with or without the steel wool on it) into the neck and you will see the difference. No oxide = smooth seating.

Wow!… this is like people have washing the algae off the bottom of their boat, but leaving the barnacles and wondering why it feels rough. Then waxing the barnacles to makes things feel a bit smoother, and running with that as a solution.

By: Jerry Reidy

Jerry Reidy — Wed, 23 Apr 2014 02:24:23 +0000

Try it side by side you will feel the US cleaned brass is harder to seat, it is an issue. I use both a US for 20 mins then the SS wet tumbler in a Thumbler for an hour. I dont have the issue with the thumbled brass but with just the US only cleaned brass I feel the difference.I have started using the case brush with a bit of case lube on it, about every 500 cases I put a drop of case lube on the nylon brush.

By: T.J.

T.J. — Wed, 23 Apr 2014 00:45:50 +0000

Factory virgin brass can’t get any cleaner than that. They don’t have a problem either.

By: Mike

Mike — Wed, 23 Apr 2014 00:05:36 +0000

I think moly is a quick fix, but not a problem solver. Moly is hard to apply even, so some case will get more than other, also I would be worry that the oal of the bullet could change in the transport and other shocks. Steel wool works fast but you end up with steel dust, and steel being harder than brass will eat up the inside of the case neck and change the neck tension, just as moly do too. So my way is too attach the brass brush on my drill and spin until a polished case neck. Brass on Brass doesnt affect the neck and the neck tension will be more consistent with a polished brass than moly.. just my way. The only problem is that polished neck and bullet stick together after a long period of thime so check your pressure sign if you reload weeks before shooting. I took time to write this , may I ask accurate shooter to publish it, as it seems that my coment are never published. thank you in advance. Mike

By: VT

VT — Tue, 22 Apr 2014 21:52:43 +0000

Why clean to the bone to begin with? An answer looking for a problem that isnt there.

By: Kris

Kris — Tue, 22 Apr 2014 20:36:37 +0000

It amazes me that this nonsense keeps coming up…

Sorry, they are not “too clean”. They are far from clean. There is an oxide layer left on the surface of the brass after cleaning with US. It’s blatantly visible in the first picture.

Put some 0000 steel wool around a wornout cleaning brush and run it into the neck with a drill or on the Casemate. Oxide layer will be removed and the necks will be polished and silky smooth.