Iodine/iodide solution for "aging" metal surfaces?

[Wade Hampton]

Hi - I hope some of you folks on this subforum can help me out.

A number of years ago I wanted to get a more aged appearance to some new tuning gears I was putting on a mandolin that had some other aged hardware on it. I read on either this or another forum about using an iodide solution, easily available at Radio Shack, that would do the trick. It's used mainly for etching circuit boards, but also works fine for what I wanted.

We still had a Radio Shack store down the road in Eagle River, Alaska then, and they had this solution in stock. I used it on those tuners and some other metal parts, and it performed exactly as I had hoped. Then I put it away under the kitchen sink, thinking I had a lifetime supply of this stuff

Here's the problem: last year we had our kitchen redone, and the bottle I had can't be found. I checked in the garage and found some other stuff that had been under the sink, but not that.

Looking online for chemicals used for etching circuitboards, I came across references to ferric chloride and potassium iodide. I think the potassium iodide is what I used, but honestly can't remember.

I did check with one of the managers at Frigid North Electronics in Anchorage (I love that business name!) He told me that he thinks what I used must have been ferric chloride. His company does not stock potassium iodide.

Anyway, the chemical I used looked and smelled like the iodine my mother used to paint on any cuts and scrapes I got. To those of you who think you know what I'm talking about, does ferric chloride look and smell like what I've described?

I'm grateful for any help you can give me on this.

Thanks in advance,


Wade Hampton Miller

[mirwa]

Wade,

What is the base metal you are trying to age, copper/brass/nickel.

Steve

[Wade Hampton]

This time it's the plating on a brand new set of gold-plated Schaller tuners. The metal hardware I'm trying to match is the antique brass cover plate and tailpiece of a National Reso-Phonic RM-1 mandolin.

Gotoh makes the tuners that go on these mandolins in their antique-look X-Gold finish, but I discovered that none of the major luthiery supply retailers in the US seem to have those in stock: they'd have to be ordered from Japan. I have gotten special orders from Gotoh in Japan, and they generally take at least three and usually six months to arrive, sometimes longer.

We're trying to get this mandolin together sooner than that, so I would like to dull down the gold plating a little bit so it matches the rest of the hardware.

Whatever it was that I got from Radio Shack back then worked perfectly on both gold- and nickel-plating. You have to apply it very sparingly and then wipe it off within seconds, but it's perfect for the task.


whm

[mirwa]

Cool,

We mainly use ebanol to "antique" brass / gold / silver etc, but this is purchased in 20 litre drums, I use that when ageing saxophones / trumpets etc before lacquering them.

When doing something like a new replacement cog on an old set of machine heads, I use a good alternative which is called liver of sulphur, in small jars about 6 dollars.

Steve

[Rudy4]

The solution you're asking about is Ferric Chloride. It dulls hardware that are nickel plated in about 10 seconds, unfortunately gold plating makes it non-reactive. That's precisely why Gotoh developed the X-Gold finish, to simulate the now popular and trendy "raw brass" hardware which has naturally aged.

This is a fairly common topic at Banjohangout.org in the building, setup, and repair forum if you want to see what else is recommended.

[Wade Hampton]

Thanks!


whm

[rogthefrog]

Originally Posted by mirwa

liver of sulphur

That sounds delicious.

[hat]

Wade, I have a bottle of the Radio shack etchant stashed away somewhere. It is great for aging tuners, etc...I think that if you can find some acid based bathroom cleaner (toilet , sink, porcelain, etc) it would do the trick but would be slower. It would need to be one of the industrial/commercial brands though. Really and acid will do the trick, some are hotter than others. I know I don't need to caution you though but I will anyway - wear your rubber gloves, and a face shield!