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 Replies: 14 / Views: 6,549 |
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Pillar of the Community
United States
539 Posts |
I'm not looking to discuss the use of Brasso on coins. I just want to understand what it actually does to the surface. We all know the visible effect but what damage has actually occurred. I assume there is an abrasive part of the product and the scratch effect is clearly a result. But what if you were to just pour Brasso on a coin, let it sit for some period of time and then rinsed off with distilled water having never touch the surface. What has happened to the coin presumably? What besides an abrasive is in Brasso? I know it is a proprietary blend of chemicals but I'm sure folks have opinions on what is in it.Has anyone ever experimented with that?
Thanks
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New Member
United States
33 Posts |
It would destroy the luster for one thing.
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Pillar of the Community
United States
7617 Posts |
All I know is it worked great for shining up your belt buckles and insignias in the Army back in the 60's.
I also know it is not, nor ever has been, good for coins. Therefore I won't use it and could care nothing about what is in it
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Pillar of the Community
 Canada
5394 Posts |
Totally destroys the coin , but go ahead !
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Moderator
United States
34397 Posts |
Ingredient list from wikipedia: Quote:
The label of Australian Brasso lists "Liquid Hydrocarbons 630g/L; Ammonia 5g/L", whereas the material safety data sheet for Brasso in North America lists: isopropyl alcohol 3-5%, ammonia 5-10%, silica powder 15-20% and oxalic acid 0-3% as the ingredients. However, the Australian version contains kaolin instead of silica for abrasives.
The online data sheet for Brasso wadding in the UK lists the ingredients as C8-10 Alkane/Cycloalkane/Aromatic Hydrocarbons, Quartz, C14-18 and C16-18 unsaturated Fatty acids, Kaolinite, Aqua, Ammonium Hydroxide and Iron Hydroxide. Brasso liquid lists a slightly different mix; C8-10 Alkane/Cycloalkane/Aromatic Hydrocarbons, Quartz, Kaolin, C12-20 Saturated and Unsaturated Monobasic Fatty Acids, Aqua and Ammonium Hydroxide. Also available are ingredients in a discontinued recipe for Brasso. Wadding: C8-10 Alkane/Cycloalkane/Aromatic Hydrocarbons, Quartz, Ammonium Tallate and Colorant. Liquid: C8-10 Alkane/Cycloalkane/Aromatic Hydrocarbons, Quartz, Kaolin and Ammonium Tallate. "If you climb a good tree, you get a push."
-----Ghanaian proverb
"The danger we all now face is distinguishing between what is authentic and what is performed."
-----King Adz
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Pillar of the Community
United States
3632 Posts |
In the U.S., the abrasive in Brasso is Silicon Dioxide, generally pulverized Quartz. The abrasive differs in other countries. Ammonia, Isoproponol, and Oxalic Acid are among the other ingredients. Its Safety Data Sheet would provide more details.
IMHO, it would turn any coin into uncollectable shrapnel.
We sometimes use it at work to polish industrial brass products.
EDIT: Spence, you beat me to it!
Edited by fortcollins
03/01/2020 9:00 pm
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Moderator
United States
34397 Posts |
Quote:
EDIT: Spence, you beat me to it! Not a race, but rather teamwork.  I agree that Brasso could good if you want a polished, shiny look to a copper object. Howver, I think that even with simple immersion, you would strip the patina right off a coin. "If you climb a good tree, you get a push."
-----Ghanaian proverb
"The danger we all now face is distinguishing between what is authentic and what is performed."
-----King Adz
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Pillar of the Community
 United States
7936 Posts |
Quite the chemical cocktail.
WIth the first two ingredients being hydrocarbons and abrasives, that makes sense for a polish. What the other active chemicals do, and how active they really are is anyone's guess if you only immerse.
Of course "only immerse" may be harder than it sounds. How can it be washed off? Water won't work.
Sounds like time for an ... EXPERIMENT!
Edited by tdziemia
03/01/2020 9:41 pm
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Bedrock of the Community
United States
17884 Posts |
Quote:
How can it be washed off? Water won't work.
Acetone or xylene. |
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Pillar of the Community
 United States
539 Posts |
thank you. I was curious. I should have done a wiki on the ingredients. I don't know what any of these do but it must remove some amount of surface just by pouring it on if patina is removed. Or assume it is removed. I may have to find a cheap brass or brass plated coin to just try for kick and grins.
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Moderator
Australia
16810 Posts |
Brasso is, essentially, liquid sandpaper. That really is as bad for coins as the phrase "liquid sandpaper" sounds like it would be. The abrasives do most of the work, scraping away the oxide layer and leaving bare metal behind.
Ammonia is a chemical reagent that is quite good at removing green carbonate corrosion ("verdigris") from copper and copper-alloy metals, without reacting with the metal itself as straight acids would. It tends to turn the metal in question an unnatural-looking bright orange colour if used by itself, so a proper "brass polish" needs the abrasives to remove the orange layer and reveal the shiny metal underneath.
The mixture of alkanes/hydrocarbons and water is intriguing; I assume some of the other ingredients (like those "fatty acids") are there as surfactants to stop the oil and water separating out into layers. Such a mixture is, in effect, very runny mayonnaise. I assume the oils are there specifically to act kind of like WD-40 and place a thin layer of oil on the metal surface, to try to prevent rapid re-oxidization of the polished brass object.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis
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Rest in Peace
United States
18456 Posts |
Hey maybe if we mix Brasso with Acetone it might work .  |
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Bedrock of the Community
United States
17884 Posts |
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I don't know what any of these do but it must remove some amount of surface just by pouring it on if patina is removed. I think everyone here just assumed you intended to put the brasso on and then rub. I seriously doubt the brasso would do much of anything if you just poured it on then rinsed it off. In looking at the ingredients the only chemically active ingredients are the ammonia and the oxalic acid. Oxalic acid is a fairly weak acid and it is there in just a small quantity. I'm not sure how copper would react with ammonia. But for the most part all Brasso is is a fine abrasive in an oil suspension. You don't rub you don't scratch or abrade away patina. |
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Moderator
Australia
16810 Posts |
If you're just going to "pour it on, wash it off", without rubbing and scrubbing, then the only active ingredient is going to be the ammonia. So instead of Brasso, you may as well just use window cleaner. For the question of "what will it do", putting ammonia on a coin that isn't corroded will do very little to it. Bright copper, brass or bronze might come out slightly more orange-looking than before. Ammonia by itself won't remove the oxidation.
The oils in Brasso aren't going to just rinse off in distilled water. You'd need to apply a solvent of some kind to get it off. Acetone would probably be the solvent of choice. Using window cleaner wouldn't have this problem as window cleaners have no oils, though they may have fragrances and other additives. Finding a supplier of pure ammonia solution would solve this problem, too.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis
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Pillar of the Community
United States
7936 Posts |
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I'm not sure how copper would react with ammonia Im aqueous solution, copper ions and ammonia can react to form complex ions like tetraamminediaquocopper(II). But in this hydrocarbon gemish, who knows? I had the same thought about oxalic acid. Why have it there when the ammonia would neutralize it? You'd have some oxalate ions running around, which also can act as ligands. But maybe it was just thrown in to get around a previous patent. And I agree ... no rubbing, and it's a different ballgame of only chemical interactions which should be fairly mild in a hydrocarbon environment. I'm thinking of picking some up and doing the experimemnts. Edited by tdziemia
03/03/2020 7:57 pm
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Replies: 14 / Views: 6,549 |
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Posted 03/01/2020 7:50 pm
