Why is my brass rainbow colored after using sonic cleaner?

[LivewireBlanco]

I have a Hornady Sonic 2L cleaner and I am using their solution with their recommended settings. I'm cleaning without heat and for one 30 minute cycle. Only a few pieces end up looking all rainbow colored but what the heck is causing it and are they still safe to shoot?

 

[noylj]

Never saw it in my experience. Call Hornady.
I have used Hornady and RCBS cleaning solutions and not had any issue. I currently use HOT water and Dawn. No acids.
You aren't adding acetic acid/vinegar, are you?

 

[tightgroup tiger]

Yea there safe to shoot. Some of mine come out like that also.
I lube my finished rounds to get the lube off and that takes it right off.

Are you rinsing them really good after your done washing them? At one time I was putting the cleaned cases back in the sonic cleaner (after dumping and cleaning it out) and putting a teaspoon of baking soda in the water to neutralize the affects of the citric acid in the Hornady one shot solution.

The only thing I noticed about using the baking soda, 2nd wash, was the absence of any discoloration and water spots. The tumbler will take the water spots off. I do get some discoloration once in a while without doing the neutralizing was but it hasn't hurt my brass in the last 5 years so I don't worry about it any more.

 

[LivewireBlanco]

I'm washing them off right afterwards in a bucket with hot water. I honestly don't know why they are doing that but calling Hornady might not be a bad idea.

 

[WestKentucky]

its from heat. sonic tumblers are basically small microwaves and the brass heats as it vibrates due ot the soundwaves. the discooloration is from the heat.

 

[ole farmerbuck]

OP said he's not using heat.

 

[heycods]

any of the acidic products can tun brass copper colored if in solution too long, I use a 9mm casing full of lemishine and 2 squirts of Dawn per gallon of hot water, an hr will turn some copper colored. It dosent hurt it. I am on 5th loading of some copper colored 9mms. Some of the old range find has to have a long soak to come clean.

 

[LivewireBlanco]

OK I just toweled them off after letting them air dry and no more rainbows....:banghead:

 

[primalmu]

There's no way an ultrasonic cleaner heats brass up enough to discolor it. You probably wouldn't even be able to tell a difference in temperature without a thermometer.

 

[WestKentucky]

farmerbuck, not trying to pick fights here, but sonic loaders vibrate the shells at a high resonance to break loose the crud, just like a microwave vibrates the particles in food at high resonance to create friction and heat the food. If it is in the sonic tumbler for any amount of time it will get warmer. If its leaving coloration similar to case hardening, then its most likely from heat.

If your adding chemical to equation then who knows.

 

[LivewireBlanco]

Now that you mention it, it does look just like case hardening. I'm willing to bet heat has something to do with it. I'm not using heat but after 30 minutes it gets pretty warm.

 

[Jaxondog]

Do you really have to keep them in there for 30 mins.? I would think that is the reason for them to change colors . I have left some in the tank for an hour one time just soaking in the same solution and it turned them a pretty bluish color. Even with my dirtiest cases I have not kept them in over 15 minutes knowingly and never had a problem with color change. Cut back on the time about half and try that.

 

[primalmu]

WestKentucky, microwave ovens and ultrasonic cleaners are in no way alike in how they operate. An ultrasonic cleaner uses high frequency sound waves to clean brass. It does NOT heat the brass up. If that were the case, every fetus that was ever subjected to an ultrasound exam would be cooked in the womb. A microwave, in contrast, bombards food with electromagnetic radiation that heats the food, not by vibrating it, but through molecular dipole rotation.

The mechanisms are completely dissimilar, and it is NOT an accurate analogy.

 

[rcmodel]

Mmmmmm?

Because you aren't dry tumbling them with polish like the reloading gods intended after about 1970 or so????

rc

 

[WestKentucky]

primalmu, your point is valid towards the ultrasound. i will have to check on some of those words that i dont understand before i accept or rebut your statment regarding "dipole rotation" however you know the big words so im betting your right.