I would only use sonic cleaning on really crusty ancients as a preliminary step. And I mean really crusty.
It's an extreme use case, which should be employed after you've exhausted plain water as a possibility. That includes long soaks, and freezing/cooling/boiling cycles. That process isn't effective against pure corrosion, just encrustations (stuff that didn't start life on the coin or part of the coin). It's up to you to first determine what exactly it is you need to remove, but if it's so bad you can't even see a date, then yeah, ultrasonic is in play. The type of damage it's capable of creating isn't relevant to coins like that, just coins whose surfaces you're expecting to end up gradable (or close to it). And obviously not something as soft as gold.
Me either! IMO the poster is POSSIBLY trying making a point. Now in fairness, anything can happen WITH ENOUGHT TIME, HEAT, AND CHEMICALS in the cleaner. Heck, you can dissolve a coin completely so you may be able to bend it on its way to destruction!!! The "holes" (actually round depressions) happen quicker. Again, with enough time, they will get deeper until a hole is made BUT LET'S KEEP IT REAL. If a tiny bubble gets "trapped" in one spot (you can actually watch this) its motion erodes the surface into a smooth, rounded, depression. I don't have time to post a micrograph but if you are interested I'll look for one. My description should be enough. The inside of the depression is dull colored metal. PS That's why I agitate the coin while in the ultrasonic.
Note: Ultrasonic cleaners are used by professionals on ALL coin types/grades; especially the XF's to UNC's. Lower grade circulated coins are best treated with more care/methods.
If you're going to release that information, you ought to qualify it by explaining vibration frequency, solution composition and temperature relevance, because the average collector will take that single sentence and go out and buy/utilize a piece of equipment which will simply beat the snot out of their coins. It's irrelevant, anyway. Ultrasonic cleaning is the equivalent of hunting squirrel with a .44 Magnum in all but the most extreme of use cases, and a tool only for those in such a hurry to get the job done that they're willing to take on extra risk in return for speed.
Snerk. I used to zero my Super Redhawk/Burris 2x combo for deer season using crow as the target. If any bird remained visible after triggering the shot, correction was necessary.
PLEASE STOP this over critical nonsense and spend your time bending coins. I don't need to release anything (Except actual, certifiable, facts) as many here on CT are the "Ex-Perts" on the subject. FACT: Professionals use ultrasonic cleaning on coins and everything else. Most of the time all the BS about solution, frequency, and temperature DO NOT MATTER AT ALL as the objects are not left in the cleaner very long. Some of us learned about cleaning things/solutions from jewelers in the 1950's. There were no such things as ultrasonic cleaners! The first time I ever saw one in use for coins was in the kitchen of a "boiler room" telemarking company! Every silver dollar they sold was "done" by a secretary! Think she/they knew anything about all the stuff you brought up? Dah? NO. She just put them in, took them out and bingo - sliders became brilliant Unc's. See...I didn't go into the rest of the treatment so you'll need to write more "fluff." FACT: Many large coin dealers own/use them. The "good" ones are expensive and of limited use to the casual collector. Nevertheless, I don't discourage learning. I hope the average collector get's interested enough to learn about just another tool for conservation. They can even read about proper technique/chemicals w/o ever using one. PS Later today I'm going to "kill some squirrels" with my 44 and think of you!
Adding some "gun fun".... An inexpensive, "good" pellet rifle w/iron sights is very accurate and there is some squirrel left to eat! We practice in the back yard on lizards. BigMoney (wife) is a crack shot and has a great "way" with squirrel & jack Daniels in the kitchen. I don't mess w/crows either. I picked-off a noisy one about 60 yards out my back window (nothing behind in the forest for a mile) and a bunch of his friends showed up and really squawked. Then one went down and tried to move him. Only crow I ever shot.
You actually want people to screw up coins. You have no understanding whatsoever of the demographic called "humanity." Not everyone is a dealer with decades of experience, and the only way to turn a "slider" into a "Brilliant Uncirculated" is to doctor it. Or, to present it to someone like that "secretary" (or the intended audience of a boiler-room operation) who wouldn't know the difference between the two if you pasted it in writing to their forehead. And if the differences in ultrasonic units and methods don't matter at all, why do you bother mentioning the existence of "good" ones and "proper technique/chemicals?" You contradict yourself within a single post. Which of your words are the truth?
Unfortunately for all of us, people (collectors/dealers/professionals/non-collectors) have been ruining COINS and EVERYTHING ELSE long before I was born and will continue to do it long after I'm dead. Facts/truths tend to speak for themselves and do not contradict in any way. If some members twist the written word and speak of extreme, purposeful possibilities...it makes for the fanciful entertainment posted in the threads that I enjoy so much! Keep it up. Here is a contradiction members can quote and I'll own up to: DON'T clean your coins. CLEAN your coins so you'll learn what it looks like.
And the way to get that experience is to DO it. Choose coins you don't mind messing up for your more extreme experiments.
I quite agree, because unlike (for instance) attribution resources, there is no ready source of information which can save the student all the hassle - and danger to the coin - of experimentation. Except, that's not a true statement. The resource I posted in the "Dipping copper" thread (to the sound of crickets) is a place where much of that information is available. It's just that people are too lazy to look for it.
