Discolored brass

[The D]

Sooooo... I brought some .223 brass into work to clean in our heated parts washer. They were only in for 30 minutes but some of the cases turned some pretty colors. Is this bad or did I find a way to clean and anneal at the same time?

 

[TheOfficeT-Rex]

Looks like brass tarnish to me.

ETA: What parts washer solvent do you use? IIRC, the ones with acid are/were being phased out in the auto industry. If it's one of the new 'bio friendly' ones, its likely just tarnish and not etching.

 

[davethedog]

I bet your pets wash has an alkaline solution which is going to oxidize parts of the alloy. Not a big deal but I would dry tumble with some polish to get it off. Anneal and you’re good to go.

Source: a man who has oxidized his own parts at work in a alkaline ultrasonic cleaner.

 

[vinniedelpino]

For a while I was using one of those lee quick trim setups that runs off a drill.

Before trimming I'd run a rag with nu-finish over the case body with the drill on its fastest setting. Shiniest cases I've ever seen. I wouldn't bother unless the case was already set up in the drill chuck.... but it'll clean up cases in no time.

 

[Quicksilver338]

I’ve done the same thing before...really cleaned the inside of the case but the outside had that off color. Stainless media were tumble with lemon juice and dish soap shined them right up again next to round.

 

[iashooter]

Stainless media in tumbler with dish soap and lemon juice or lemi shine or walnut shell media in a vibratory unit with some nu-finish or flitz will get them looking like brand new! Many options will work to shine them up as listed above.

 

[The D]

Thanks for all the replies, everyone. The pic I posted doesn’t show some of the colors the cases turned very well. There definitely is some tarnish from a cleaner but there is also some discoloration that looks like overheating. The cleaner is from Cuda and it we have a bucket of their own brand of cleaner. I’m not concerned about the tarnish as much as any potential damage from overheating. The heater is set at 180 degrees and the cases were in the cleaner for ~30 minutes, anyone think there’s anything wrong with this? In the future should I set the heat lower and/or run for less time? Or am I worrying for nothing?

 

[davethedog]

Thanks for all the replies, everyone. The pic I posted doesn’t show some of the colors the cases turned very well. There definitely is some tarnish from a cleaner but there is also some discoloration that looks like overheating. The cleaner is from Cuda and it we have a bucket of their own brand of cleaner. I’m not concerned about the tarnish as much as any potential damage from overheating. The heater is set at 180 degrees and the cases were in the cleaner for ~30 minutes, anyone think there’s anything wrong with this? In the future should I set the heat lower and/or run for less time? Or am I worrying for nothing?

You're worrying for nothing. No parts wash gets hot enough to overheat your cases, you're gonna need a good torch for that. All that discoloration is oxidation.

 

[lightman]

180º for 30 minutes won't be hot enough to hurt anything. I use the oven set at that temp for 20-30 minutes pretty often.

 

[The D]

You're worrying for nothing. No parts wash gets hot enough to overheat your cases, you're gonna need a good torch for that. All that discoloration is oxidation.

Ok, good. I didn’t really think that was the case but I would rather double check than find out the hard way.