Something to dissolve crud.

[jondar]

Hi, need some help.  I was metal detecting   at a pre Civil War site where a battle (well, more like a skirmish) was fought between Slavers and Free State men.  I found an object which, if on top of the ground, you would think was a small rock.  It beeped the detector and was about five inches deep.  In looking at it I can visualize that it is "shield" shaped and is about and inch and a half high and an inch wide, quarter inch thick and tapers to a blunt point at the bottom.  I put the detector into the most discriminating mode, shutting out most everything except coins and it comes up signalling coins. Thick aluminum objects will trigger the beep but this is too heavy to be aluminum.  What can I do to remove this limestone-crud coating without harming the metal underneath?  I have it soaking now in olive oil, which someone told me will remove the gunk from old Roman coins.  I can furnish photos if it will help.  thanks for any suggestions.

[talesofthesevenseas]

I think you're going to need to determine what kind of metal it is before attempting to clean it. Does a magnet stick to it? A photo would help, it sounds very cool!

[jondar]

No, the first thing I did when I got home was check it with a strong magnet.  No reaction.  Some pinpoint sized spots seem to show thru with a silver sheen.  I'll get it out of the olive oil, wash it and try to get some decent pictures.  It may, after all, be just a coin.  Thanks for the reply.

[jondar]

Not good.  Some friends came by yesterday ande I showed them the object.  All agreed that this was a piece of aluminum which had melted in a fire and cooled into the shape of the object.  Very very possible as the area I found it in is less than a city block from a power and light generating plant.  They said what I thought was lime formations was slag. 

[talesofthesevenseas]

Interesting. I would guess it is very light weight then? If it were lead, it would be heavy like a fishing weight.

[jondar]

Well, not real light, about like if you had two silver dollars in your hand.  Around the edges the bare metal has come thru after soaking it in vinegar, and the metal is very hard like aluminum.  Interesting markings on it but I now realize it's just the results of the way it cooled.  Well, like the saying goes, "chicken one day, feathers the next."