Brass Casings have light blue spots all over them?

[HighlyAdaptive]

Hello all,

I took my Martini Henry out today and fired her for the first time. Had a great time. I came home and began to clean my brass and I got the brass as good as clean as you can when you are using black powder. I put them in the sun to dry and now that I checked on them I notice light blue green spots all over the brass. What is it exactly? It looks like what the attached picture shows (that's not my brass, it's a pic I found on the internet as the lighting is bad right now).

[kcheung2]

That looks like copper corrosion. I hope yours doesn't look that bad, some of those look like they've been outside for years.

How did you clean your brass?

[Maht_g]

Corrosion for sure. I don’t use black powder, might be typical for it to corrode brass fast? Using smokeless powder I’ve only seen that type of corrosion on brass that was outside or stored in damp location for extended time... did you wet tumble or just wash it with dish soap? If i find brass as bad as the pic, I throw it away...

[rsrocket1]

Look up "cleaning black powder brass cases". There are ways of cleaning BP cases that will not result in corroded cases like you have. It's interesting that some cases look clean while others look like they were sitting out in the mountains for months. Your cleaning method might be OK, you might need to simply fix your process.

Those cases might be salvageable for low pressure BP shooting and since they look like low pressure cartridge cases, maybe even for smokeless powder reloading, but I would not risk it. Saving a few pennies per case and risking a blown up gun is not worth it.

Make sure you really clean your gun. Losing a few brass cases isn't too bad, winding up with a pitted and corroded gun will be painful.

[ironhorse1]

Copper Sulfide

Blackpowder as we know is made up of Saltpeter/Potassium Nitrate,Sulfur and charcoal.

So we have a salt in combination with Sulfur which acts naturally on the Copper in the brass to produce Copper Sulfide.

The solution to clean would involve a mild acid such as vinegar or lemon juice.

Problem is the Copper is leaching out of the brass and the cases will no longer be usable.

Cases must be cleaned ASAP to stop the leaching of the Copper.

This is what I have found with a quick search as I'm not a chemist nor did I stay at a Holiday Inn last night.

I have fired a few BP loads in brass cases but never had this occur. I just threw the cases into the tumbler.

In the future I will separate,wash with vinegar,rinse and tumble.

irh

[rsrocket1]

Lemishine is better than vinegar. It contains citric acid. Plain citric acid would also work but Lemishine is easier to get (Walmart in the kitchen dish soap area). The citric acid passivates the brass rather than leaching out the zinc like vinegar does and makes the brass more corrosion resistant but more importantly, it does not eat the zinc in the brass which will leave your brass pink in hue.

[Tom-ADC]

I keep a large pretzel jug the big plastic ones about 1/2 full of water and Dawn dish washing soap with me when I'm shooting BP I drop the fired rounds in ASAP my brass doesn't look like yours.

[HighlyAdaptive]

I keep a large pretzel jug the big plastic ones about 1/2 full of water and Dawn dish washing soap with me when I'm shooting BP I drop the fired rounds in ASAP my brass doesn't look like yours.

Mine don't look that bad as the pictures I included. Mainly just some light "pitting". Debating whether I should throw them away or not...

[rm1911]