Friday, July 8, 2011 — It’s a rainy morning here in the Ohio Valley, and I probably should be on the air instead of on the computer!
My main key at the operating position is still my recently acquired T. R. McElroy P-500 “Professional” model. I’ve not really cleaned it up yet, the base is dusty but unblemished for the most part. The key still has the original owner’s callsign in Dymo label stuck on the front too. I took time to break out the Tarn-X and clean up the contacts.
I have found that Tarn-X works wonders on CW key contacts. There’s a guy on eBay who sells a mildly abrasive key contact cleaner strip; I bought one but don’t use it. I’m not going to put anything even mildly abrasive on the contacts of the keys I own! The Tarn-X removed the tarnish easily and its simple and safe to use. In fact, I usually clean the contacts without removing them from the key.
Tarn-X is a mild sulfamic acid solution (Tarn-X is 85-95 percent water according to the MSDS sheet) that removes tarnish from silver and other metals. I’ve used it to brighten up copper, t00.
The key with using Tarn-X is controlling the application of the product — I dip one tip of a cotton swab into the Tarn-X solution (getting it saturated but not dripping wet), then apply the swab to the contact that needs cleaning. It’s OK to “scrub” lightly with the swab if necessary to remove stuck-on dirt or grime, but the Tarn-X does the work of removing the tarnish. Once the tarmish is gone (it doesn’t take long), I dip another cotton swab in plain tap water and I use it to clean the cleaned contact of the Tarn-X (basically you’re diluting the solution further and flushing the Tarn-X away). The directions on the bottle have more details, but you get the idea.
I’m not sure it can damage them, but I recommend keeping Tarn-X away from all painted surfaces and plated surfaces as much as possible. I have not seen Tarn-X attack any of the plated parts of my keys (like the dot contact screws, etc.), but I think its a good idea to make sure you keep Tarn-X away from surfaces that aren’t being cleaned — just in case.
Coin collectors and silversmiths will tell you that Tarn-X is the spawn of Satan — it can destroy good silver, especially if dipped and left submerged too long, or if the product is not flushed away adequately. We’re talking about cleaning small silver contact points, not fine sterling. Another cleaning product — that’s non-acidic — is a mixture of baking soda and water. I just found that, and may try it. It sure sounds a lot messier than my cotton swab soaked in Tarn-X.
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