Discolored Brass After Sonic Clean

[Thumb]

I've been cleaning my brass for about 3 years now and this is the first time I have ever seen this after about 5,000 pieces of brass cleaned. I use Hornady's brass cleaning solution then tumble in walnut. Here's a picture of the results.

Any ideas what is causing this and are they any good now?

 

[orbitup]

I had that happen when I started using one. I thought it was because I left a copper plated bullet in there but could not replicate it. Mine was with 308 brass and I used it anyway without any problems.

 

[Thumb]

I've done about 5 batches so far and each one has done it, I don't believe any copper was in there but it does look like copper doesn't it?
FYI, it's only happening with the FC and Speer brass but not all of them, just maybe 15 out of a hundred or so.

 

[orbitup]

Now that you mention it I only had it happen to one brand of brass too. I don't remember which.

 

[Dusty Stevens]

whatever acidic addition youre adding is reacting with an alloy those brands have that are turning

 

[Webster]

I've been cleaning my brass for about 3 years now and this is the first time I have ever seen this after about 5,000 pieces of brass cleaned. I use Hornady's brass cleaning solution then tumble in walnut. Here's a picture of the results.

Any ideas what is causing this and are they any good now?

Walnut hulls are probably high in tannic acid like oak leaves. There would have to be moisture present to draw the tannic acid or other chemicals out of the walnut hulls. Wet oak leaves will stain cement brown. Stains usually have microscopic thickness. I don't think you have a corrosion problem. Birch Casey brass cleaner should clean them up or reclean and make sure there is no moisure in the walnut abrasive. Use the walnut without Hornady brass cleaner. Others on this website will probably recommend what they use for vibratory cleaning. I use SS pins in a tumbler. All brands of brass have similar composition. The amount of zinc varies a little. Looks like a stain and not a chemical reaction with the brass?

 

[Thumb]

This is happening after the sonic cleaning so it's something in there that's doing it. I'm using the same bottle of Hornady cleaner solution, distilled water and that's it and all of a sudden this happened. The walnut tumbling comes after and it actually makes the brass look just a bit better again. I've got a F.A.R.T tumbler and SS media but really do not like using it, way too much trouble and time to use. I've just changed the Sonic solution with new fresh water and will see if it continues.

 

[JRS]

The solution contains citric acid. Are you leaving it in there for too long a period of time?

 

[Thumb]

The solution contains citric acid. Are you leaving it in there for too long a period of time?

I have always cleaned it at 90 minutes so I don't think so. I did put in new water(distilled) and cleaning solution(1 cap full) just like I always do and did 2 more batches and they came out good. I'm thinking maybe something else got in the solution or something in one of the brass cases that did this.

 

[fguffey]

Many years ago that happen to me, I left my brass in the vinegar too long. I was using the 5% stuff, that is when I fixed the time limit to 15 minutes, I only used vinegar for the worst of cases to reduce tumbling.

So, I suggest you reduce the acid content or reduce the amount of time when using acid. Before vinegar I used some other stuff, the other stuff came with a warning label, they set the time limit to less than 2 minutes with two rinsing's in boiling water. When finished the cases turned black. The other stuff was great for cleaning cast iron and old tools.

F. Guffey

 

[Thumb]

OK, I just noticed something and I believe I wasted my time and yours. I just got some more brass out of my big bin and noticed that some of the brass was already that copper looking color. SO something must have gotten to that brass before I got it. Sorry guys.

 

[Texas10]

Looks to be surface bleaching the Zinc out of the brass. Maybe your bottle of cleaner has gone too acidic with age or old primer residue has become acidic and compromising your cleaning solution. Maybe a prewash before U.S. clean would be appropriate. You didn't by chance put any aluminum cases in with the brass, did you ?

 

[Thumb]

No Texas10, no aluminum. Look at my post right before yours, I found the problem.

 

[Zero333]

No Texas10, no aluminum. Look at my post right before yours, I found the problem.

You didn't find the "actual" problem.
You only figured out that it's not the sonic cleaner that's making this problem.

 

[Thumb]

Well, I sort of found it, it wasn't anything I did. Now to say what actually caused it would be up to Sherlock Holmes.

 

[MN50Shooter]

I've had this happen once using Dawn & Lemishine with ss pins. I turned the brass back to a brass coloration by filling a bucket with enough of the hottest tap water I could get and adding a very small amount of Lemishine as I was filling the bucket (just deep enough to cover all brass). I then dumped in the discolored brass, and all of it immediately, returned to a brass color.

 

[Thumb]

I've had this happen once using Dawn & Lemishine with ss pins. I turned the brass back to a brass coloration by filling a bucket with enough of the hottest tap water I could get and adding a very small amount of Lemishine as I was filling the bucket (just deep enough to cover all brass). I then dumped in the discolored brass, and all of it immediately, returned to a brass color.

Thanks for that info, I'll try it and see if it works on mine. Don't really need to but what the heck.

 

[Thumb]

Well, I tried your Lemishine & hot water trick and it did absolutely nothing...Dang! I decided to try some Brasso on one of the cases and it did bring back the brass color but with only about 20-30 cases being discolored out of a couple thousand, I'm not going to worry about it.

 

[dickn52]

When this happened to me, I dried everything, threw it in a tumbler (dry) with walnut treated and ran it for an hour. Nice brassy brass.