Finger prints on my brass

[Tswafford]

I was wondering if someone could answer a question for me? I went to get my brass out of my tumbler yesterday and it was all shiny and new looking except for tarnished spots that were clearly fingerprints. I'm using corn cob media and a little nufinish. Any idea why this is happening? Thanks

[bhn22]

Corn cob polished brass to a high luster, but is not abrasive, and will not remove blemishes. An abrasive media might not get your brass clean anymore either, but it's your best bet.

[Tswafford]

Never had this problem till now. Brass is really shiny except for the tarnished finger prints

[bangerjim]

Someone who had high body acid in their sweat handled them and caused the prints. It will not show up until the other parts are shiny. Some people just do not chemically get along with brass!

An abrasive is what you need..............or chemically clean them B4 tumbling.

bnager

[w5pv]

Decap and then do the citrus acid was and if you want a brighter finish tumble them for about 20 minutes.

[Tswafford]

I'm sure it is discussed here but could you tell me how to do this and what I would need to buy. Thank you

[44Vaquero]

Your skin is too alkaline! I have the same problem, I leave finger prints on bare metal and tools all the time. Try using some hand lotion before handling the brass.

[DLCTEX]

I'm sure it is discussed here but could you tell me how to do this and what I would need to buy. Thank you
Thread: Citric acid brass cleaner. All I use anymore. Try it this way:http://castboolits.gunloads.com/showthread.php?83572-Citric-acid-brass-cleaner&highlight=citric+acid That works.

[medalguy]

My business uses a lot of brass, and some people do have something in their body chemistry that tends to tarnish brass pretty fast. You might do as most of our employees do-- wear nitrile gloves when handling brass. That works for sure.

[Tswafford]

I figured out the problem today. Don't make sense to me but I duplicated the problem exactly. I had a bunch of .223 brass that needed cleaned. It was in plastic bags that was starting to get holes in it. So I go in the house searching for something to put them in. I find a empty plastic container about 1 gallon in size. It had those little packs of washing detergent that you throw in your washing machine. That is what I have been putting my brass in after tumbling. Today I tumbled some. They looked better than new out of the tumbler. I take the lid off my plastic washing detergent bucket to dump my brass in and everything was really tarnished. I figured that was the problem so I went ahead and dumped a few brass in the bucket and low and behold they started turning right away! Now I have close to 1000 pieces of tarnished brass. Is there anyway I can get them back shiny? Can I reverse this tarnishing? I tried tumbling some to see if that would help but it didn't do anything. Thanks for your help
Terry

[Del-Ray]

The powdered citric acid will brighten them right up. Four teaspoons in a gallon of hot water. I boil it, then pour it over brass in one of those obscenely orange homer buckets from the Home Depot. Then I scoop in four measures of citric acid. Mix it up good, and let it sit for about twenty minutes or so. Citric acid is food safe, also known as pickling salt, or sour salt. Sold in the canning section.

[bangerjim]

Citric will work well.

Do NOT use any other strong acids like sulfuric (battery acid) or hydrochloric (muriatic) (pool acid). They can leach the zinc and other alloyed metals out of the brass alloy and change the properties of the brass......basically makes them brittle and total scrap. Those acids are highly hydrogen ion active. Citric acid, like acetic acid (vinegar), are safe and are very low hydrogen ionic strength.

pH, the measure of caustic/acid levels, is relative and should not be used to decide. Battery acid is ~3-4pH......Coke is ~4pH. Excellent example of hydrogen ion potential!!!!!! I don't drink battery acid, I do occasionally drink Coke (prefer Pepsi). Soda gets it acidity from carbonic & citric acids.

Your containers of washer soap have HIGHLY caustic (soap) residue and are reacting with your brass. (both caustics and acids will react) ALWAYS wash at least 3 times any reused container for anything you do!!!!!!!!!

Good luck with our "chemistry" experiments!!! :drinks:

banger

[Garyshome]

Use rubber gloves [nitrile] to protect you and the brass!

[Griz44mag]

If that's your toughest issue, then you have no issues!
:grin:

[d garfield]

I mix my corncob and walnut shell together,it works great.

[reddoggm]

If that's your toughest issue, then you have no issues!
:grin:

Unless you don,t want to loose fingerprinted brass in the wrong place

[Bonz]

before I switched to wet tumbling with SS pins, I used to add a handful of 'raw' white rice to my corncob as an abrasive

[Teddy (punchie)]

If not too bad I use number 3 steelwood cheap and fast. I just check the brass and steel wool. I used this years ago on shot shells, way before I had a tumbler. Have to watch getting to crazy and going to far, taking off too much brass.


I use oil gun oil, mineral oil, cooking oil on my hands before touching brass. Had a helper last year everything he touched turned.

I add mineral oil to my medium with brass cleaner. Walnut works better for me.

[Tswafford]

Thank you everyone