OK, an update from my last post. I tried Loco Digger's mix of lemon juice and salt on discolored clad dimes & quarters instead of the water/magic powder mix. Results? like night and day. With the old mix, they came out clean of course but often still very discolored as I had said before, with the lemon juice/salt mix, they all looked brand new, no kidding, night and day. It was a "wow" factor. Now, IS it all that important? No, not really, but what I've done, is that I started to keep all the coins I've found since I've retired. Have 3 boxes, one each for pennies, nickels and dimes, and mason jars for quarters, this is all for a kind of "show & tell" type of thing for anyone invited into my "Fort" located in the garage. Example; Since Jan. 2015, say 6600 pennies, 1000 nickels, 1600 dimes & 1100 quarters, it just looks kind of neat to those interested. They like to grab a handful, and run the coins through there fingers, but now, with what I call the "Loco Digger" mix, nickels, dimes, quarters are going to look even better to them. Now having said all that, here is something not to do. I tried lemon juice/ salt with 100 pennies in the tumbler, well the tumbler after a time was taking on the shape of a balloon, stopped it, took it OUTside, and carefully pried of the lid when it "popped" off. I'm thinking the mix did NOT react well with the Zinc? It was weird, on some, (ones that had started to corrode in ground) the copper was gone, and you truly had "Zinc" pennies, first glance looked like the 43 steel 1C, the brass pennies, 59 thru 81, took on different hues, kind of pretty though. And so, with nickels, clad dimes & quarters, by far the lemon/salt, pennies, I'll stick with water/powder mix, so as to not hear a muffled explosion out in my fort, unless any of you have a better thing you use for them, instead of ordering the "magic" powder from the shipper. For what it's worth, I tumble for about two hours, that amount of time works just dandy. Oh yes, two more things, one is for say the "newer" guys & ladies out there. I myself do not tumble silver coins, and NEVER tumble any "Key" date or "Semi-key" date coins. everything I have tumbled are Clad coins, and memorial back pennies and newer, 1959 till present, (have done some Wheaties that were SO corroded or crusted over, there was nothing to lose really), and two, no matter how many years you've been involved in this hobby, 40yrs or your 1st, we can always lean some things from other forum members here. Just like here, what I picked up from Loco Digger, and where he may have picked it up over time from others.