Citric Acid Brass Cleaning

calibrecarstairs

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I always end up with a few problem children after picking up range brass. They are badly stained and no amount of dry tumbling will get anything even near a shine. The before pic is after twelve hours of dry tumbling.

I came across a site advocating citric acid to get them cleaned up and here is the result. I think after a little tumbling they will be good as new.

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Almost any dilute acid can be used to clean brass.

My favourite is phosphoric acid. Once upon a time I picked up a half litre bottle of 85% at a hydroponics store, it lasted for years diluted to 1-2% for soaking brass. I read somewhere that dilute phosphoric acid is what the factories use to remove the heat tint from annealed cases before loading. Theoretically one could use a little cola in water, as cola contains a fairly strong dose of phosphoric.

I also picked up a container of sulphamic acid from the bathroom section of a home improvement store. This acid is used to clean "grout glaze" from the surface of newly installed ceramic tiles. I haven't tried it yet.
 
White vinegar and water in my ultrasonic gives the same results. And buying it two gallons at a time at Costco is super cheap. Much cheaper than lemon juice for sure. I don't know what Lemishine costs but I keep the vinegar around for laundry use as well so it makes sense to use just the one product.

I mix it 1:4 of vinegar to water. Then a dash of liquid laundry detergent to cut any oils that might be present.
 
Almost any dilute acid can be used to clean brass.

My favourite is phosphoric acid. Once upon a time I picked up a half litre bottle of 85% at a hydroponics store, it lasted for years diluted to 1-2% for soaking brass. I read somewhere that dilute phosphoric acid is what the factories use to remove the heat tint from annealed cases before loading. Theoretically one could use a little cola in water, as cola contains a fairly strong dose of phosphoric.

I also picked up a container of sulphamic acid from the bathroom section of a home improvement store. This acid is used to clean "grout glaze" from the surface of newly installed ceramic tiles. I haven't tried it yet.

Muriatic Acid from your local hot tub/pool supply store and at some WalMarts etc sell it as well. It's just a diluted hydrochloric acid and it's cheap.

As the folks here have said, you don't need a lot. Less is best. I have gotten to the point where I only tumble my brass in pins and acidic fluid to the point it's clean. I don't care if it's shiny and bright.
 
Muriatic Acid from your local hot tub/pool supply store and at some WalMarts etc sell it as well. It's just a diluted hydrochloric acid and it's cheap.

As the folks here have said, you don't need a lot. Less is best. I have gotten to the point where I only tumble my brass in pins and acidic fluid to the point it's clean. I don't care if it's shiny and bright.


That's interesting may cut back on the suds to a minimum to see what the results look like
 
Needing around 5 grams of citric acid for 10-15 litres of water is a very small amount. Citric acid is very cheap, easy to handle and easy to store. You're looking for a weak acid to barely remove the tarnish, not a strong acid solution that will begin to react with the copper and precipitate it back on to the brass in an orange color or leave it in solution as a greenish tinge to the water.

I've tried a few sources including the salt and vinegar solution. Salt and vinegar worked really fast, but after more than a few minutes continued to react and left dull and orange brass. Does it hurt? Probably not for my proposes of reloading 9 40 and 223 for fun.
 
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I have been using critic acid as a last step before the last crushed walnut tumble /drying step
I have found it helping clean out residue out of the primer pockets /clean the inside of the case
Remove annealing colour / and remove the black around the neck of the case
I have found the critic acid softens /loosens the primer/ powder residue and the last short time in the crushed walnut takes it right off
1 tea spoon (or so) per liter of hot water -let it sit for 15 min -- Drain -- rinse -- and in to tumbler to dry
1 liter will do about 2-300 cases in a ice cream container (2 and 3 batch let sit longer)

No more primer pocket cleaning for me
 
Another range trip and more problem children.

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After a few minutes in solution and some swishing about things are already looking better. It's always the worst ones that have the most pink.

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