Myself and several others I know of do the exact opposite. Walnut to clean, because it is a harder media, and corn cob to polish, it removes traces of abrasive additives and gives a nice bright
polish.
New to tumbling: how long to run the tumber?
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Myself and several others I know of do the exact opposite. Walnut to clean, because it is a harder media, and corn cob to polish, it removes traces of abrasive additives and gives a nice bright
polish.Yep you got it backwards... walnut to clean, corn cob to polish... if your doing two steps like this your maybe a bit of clean freak... or just plain anal about precision... I have never needed to use both media's. but hey what ever floats your boat !
The toughest brass I have ever had to clean was black powder brass. Almost impossible to get the stains off. You need to wash it out as soon as possible after shooting, vinegar water solution works good, to prevent this. Once it was reasonably clean I just went ahead and used it anyway, but it will never be "shiney". Pet stores sell walnut media as pet bedding, way cheaper then the specific gun stuff, FWIW. - dan
X2 corn cob works just fine on its own. I see no need for adding extra chemicals such as brasso, or car wax. If your using range brass, then some will tumble first with walnut, then for the final tumble they use corn cob. Seems like alot of extra work though. I figure if you can't get brass clean after a few hours of tumbling in corn cob, get rid of it!
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Try 2 tablespoons of brasso.
Contrary to popular misconceptions, the amount of ammonia in BRASSO is so small and for a short period of time that it has no effect on the brass. Further, the ammonia evaporates very quickly out of a tumbler.
From Wikipedia
The problem of season cracking is known from brass cartridge failures during the monsoon season in India in the 1920s, failures which were caused by attack of the metal by ammonia. The edges of rifle cases cracked and could cause misfiring of rifles. The gas was produced from animal manures during the high temperatures and humidities of the monsoon, and by the high levels of residual stress produced by forming the barrels of the cartridges. As a type of stress corrosion cracking, it is characterised by deep brittle cracks which penetrate into affected components. If the cracks reach a critical size, the component can suddenly fracture, sometimes with disastrous results. However, if the concentration of ammonia is very high, then attack is much more severe, and attack over all exposed surfaces occurs. The problem was solved by annealing the brass cases after forming so as to relieve the residual stresses.
Ammonia
Attack takes the form of reaction between ammonia and copper to form the cuprammonium ion, a chemical complex which is water-soluble, and hence washed from the growing cracks. So the problem of cracking can also occur in copper and any other copper alloy, such as bronze. The tendency of copper to react with ammonia was exploited in making rayon, and the deep blue colour of the aqueous solution of copper oxide in ammonia is known as Schweizer's reagent.
Materials
Although the problem was first found in brass, any alloy containing copper will be susceptible to the problem. It includes copper itself (as used in pipe for example), bronzes and other alloys with a significant copper content.
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I've heard that and plan to try it as soon as I use up my current can of Brasso. Not because of any worries about ammonia. I have always just taken the can of Brasso and dumped a "glug-glug" or so into the tumbler so I'm sure I have gone well beyond 2 tbsp.
The reason I'm gonna try nu-finish is the containers are bigger IIRC. That means less chance of running out of polish.
But thanks for the reminder.
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If it's as shinny and clean as you want it, you need not run it further, you're just wearing the media down.
As the media gets older, or if you have some dirty brass, you will need to run it more.
I add a car polish to mine when it gets too old and it taking too long. It's not Nu-Finish, it's another abrasive polish. Just a tiny amount works wonders, maybe a half tablespoon, just a squirt.
I use corn cob to clean (2-3hr) and corn cob treated with liquid media additive (lymans, fankford etc.) to polish (2-3hrs). The clean gets rid of the heavy dirt and residue the polish takes any remaining dust / film off and really make it shine.
I would never put any of my brass that colored Lyman crap. The cases end up covered in it and its been know to wear out barrels prematurely, especially the red stuff (jeweler's rouge). Look inside you cases after tumbling with either, they're full of green/red dust.
You can buy untreated walnut media in many pet stores for a fraction of the price and it cleans and polishes as good as any other dry media I've ever used. They sell it as lizard litter. If you can get Frankfort Arsenal walnut though, its really nice. Its so small that it doesn't get stuck in the flash holes at all and gets some of the stuff in the primer pockets off. Sometimes they sell similar stuff at industrial supply places. For polish, just add a blob of Flitz.
I don't bother with walnut for rifle brass anymore (only pistol). 1mm ceramic beads with a cup of water and a drop of Dawn gets the brass clean and shiny inside and out. Cleans the inside of the necks and the primer pockets too. Not quite as good as ultra sonic, but much larger batches. Works well in both vibrating and rotary tumblers. Why bother with dust, when I can get results like these:
http://www.bpcr.net/site_docs-results_schedules/documents/Ceramic_Bead_Vibratory_Cleaning_of_Brass_Cartridges.htm
You can buy untreated walnut media in many pet stores for a fraction of the price and it cleans and polishes as good as any other dry media I've ever used. They sell it as lizard litter. If you can get Frankfort Arsenal walnut though, its really nice. Its so small that it doesn't get stuck in the flash holes at all and gets some of the stuff in the primer pockets off. Sometimes they sell similar stuff at industrial supply places. For polish, just add a blob of Flitz.
I don't bother with walnut for rifle brass anymore (only pistol). 1mm ceramic beads with a cup of water and a drop of Dawn gets the brass clean and shiny inside and out. Cleans the inside of the necks and the primer pockets too. Not quite as good as ultra sonic, but much larger batches. Works well in both vibrating and rotary tumblers. Why bother with dust, when I can get results like these:
http://www.bpcr.net/site_docs-results_schedules/documents/Ceramic_Bead_Vibratory_Cleaning_of_Brass_Cartridges.htm
