Munted is a wonderful NZ word that means ruined, wrecked.

I’m doing my 2024 metal detecting inventory… my first year as a detectorist was fruitful. I found loads of trash, and loads of “interesting” lost, broken or discarded stuff that’s ultimately also trash. I found almost $250 in spending money along with bunches of older coins. Over 20 lbs of lead for the scrap metal man, along with a couple lbs of brass and copper scrap. And I found enough gold and silver jewelry that I could pay for the entire detector setup!

One of the challenges presented by all this booty is what to do about the damaged coins. Modern NZ coins are alloy-plated steel. This means when they sit in the ground, especially if salt water is involved like at the beach, they corrode quickly. The iron rusts and erupts out of the alloy shell like a bratwurst popping its casing on the barbecue. And even the older pure(r) copper coins corrode eventually.

Online metal detecting forums are full of “magic” and “secret” cleaning methods. Of course you shouldn’t clean collectible coins, but these aren’t so worth a shot at cleaning up. The picture above is a whole fistful of coins I soaked in olive oil for a couple of weeks, a method which many people swear by. Olive oil has just a little bit of acid in it, and so it slowly removes some of the corrosion from the coins without just eating them.

It worked up to a point, but most of these coins are still munted. I’ll either need more patience, a slightly stronger acid, or just move up to the better method, electrolysis.