Well vinegar is acetic acid, also corrosive to copper, especially to the delicate luster. Acetic acid can also be created when improperly cleaning copper with acetone, lol
I did everything from electrolysis to boiling in baking soda to copper also. Because I've never seen anyone else do it. And I shared it here on coin talk. And got my ass ripped up for it. But I don't care. Some people like the results and some people don't and there are educated opinions and there is human opinions and I like everyone's.
No I get it, your experimenting. I've been an unsupervised lab tech for 15 years now and a coin collector for only about a year. I did more than my fair share of experiments on coins just out of curiosity and boredom. But since becoming a collector I try to take care of them now. When it comes down to it they're your coins and you can do what you want with them. Just don't "clean" mine, lol.
I bought this set for 10 bucks just to do this. This is a continuation from another thread which I may have misunderstood by someones definition. I gave up on screwing with coins but that thread once again triggered me... https://www.cointalk.com/threads/79-sba-san-francisco.389352/
I have no problem using acetone. The experiment done at Stoney Brook as I remember was underwritten by a firm selling an alternate cleaning agent for connecting copper tubing and fixtures that was more expensive than plain acetone, and thus didn't sell well. The experimental environment of UV, water vapor , and temperature was ( IMO) extreme beyond normal . Think of a steam autoclave with ultraviolet lights. If any want to read it themselves: https://www.sciencedirect.com/science/article/abs/pii/S0013468601003590 I paid the first time to read it , but not again. If you are in sciences at a University, you probably can get it to read for free. There are 2 supplemental papers also for obvious reasons I believe. If I was living on the planet Venus, I would use that product for my copper still ! IMO, Jim
You can use industrial grade ammonia too and it will shine them up. But I wouldn't recommend it because a moment too long and the surface is stripped. I've tried everything and this is the very last thing I do to save a coin. It rarely works.
I had to find my system myself. It's great seeing others share their successes and failures. A lot of moderns are simply ruined and a lot more are lost every day through inaction and lack of concern than through poor cleaning techniques.
I've read the Stoney Brook report, they recommended using isopropyl for copper part degreasing. Acetone is fine to clean with if you remove any remaining residue after cleaning. The problem with acetone occurs if residue is left in contact with copper for prolonged periods. After that an oxidation layer will begin to form on the surface due to a reaction from the acetic acid byproduct to the air. Acetic acid is found in household vinegar which is an important ingredient used to artificially patina copper.
That would be the base equivalent of diluted hydrochloric. Acids and bases both being corrosive to metals are going to be invasive to the surface of alloy coins, how invasive? Guess that depends on dilution and exposure but they sure do effectively remove contamination, or "toning" if you prefer. Now after a few days, even though I thoroughly rinsed the coins after the HCl dip I am noticing a dullness with the clads, especially the dimes and toning on the cents. So either I have not successfully neutralized the reaction or the surfaces have been chemically altered and are rapidly oxidizing. Like I said. I had to try it.
I've never heard of using acetone for prepping copper joints. I can't imagine why anyone would want to. The goal for joining copper pipes is to remove any oxidation from the surfaces to ensure a good flow and consistent bond of the solder. This is done by mechanically stripping the copper surfaces to be joined with an abrasive and then applying Flux, being the trade favorite, for the final prepping of the surfaces and serves two purposes, 1 is to immediately inhibit oxidation and chemically etch the surfaces and 2 is to create a liquid tension to the molten solder. Pro tip... always preheat your pipes a bit before joining to avoid a positive pressure build up inside the pipes, while sweating, which will resist the flow of solder into the joint, especially on inline and or final connections.
For anyone hoping to get something useful from this thread, I found, so far, this is maybe the least invasive method for removing contamination and I think it's sensible being that the only thing used is water. The results are not spectacular but boiling the coin for 10 minutes did remove some ugly stuff while leaving the toning mostly in tact. At least for this particular type of crud.
Acetone is used to remove any oils from the parts to be soldered. With HVAC, I start with acetone. An abrasive is next, brushes and emery. Next is a solder with a percentage of silver. The silver helps with joints that will deal with vibration. Even with regular plumbing, I clean off oils with acetone.
I'm sure it don't hurt but seems above and beyond what would be sufficient for a good bond. Most companies would not want to deal with the extra layer of danger and ppe and OSHA while doing hot work. Why can I never find anyone who takes such pride in their trade?
And you are correct to disagree. When a coin is dipped correctly the one and only way there is to tell that it was dipped is by using deductive reasoning. There are absolutely no other tells. And anybody that says different is simply wrong.
