Photo 1 — Photo courtesy of

If you read my column regularly, you know I typically focus on electric guitars and useful ways to mod them. But recently I started throwing some acoustic-oriented topics into the mix (“Conquering Classical Guitar String-Changing Terror” and “Cleaning Up an Acoustic from the Inside”), and since then I’ve received numerous requests for another column dealing with acoustic guitars.

So this time around we’ll look at effective DIY methods for restoring vintage tuners. To illustrate these techniques, I’ll use antique brass tuners from a 1924 German classical guitar that came into the shop for a full restoration, but you can apply the cleaning and restoring principles to a variety of guitars with non-sealed tuners, including flattops, old-school electrics, and even basses.

As you can see in Photo 1, these tuners were in pretty bad shape: The brass was really tarnished, the buttons were scratched and covered with dirt, and the gears were so packed with hardened grease they wouldn’t turn. Rather than replacing the tuners, the customer wanted them fully restored, so the first step was to make them functional again. I knew once they were working I could make them look nice, too. I’m going to show you how I accomplished these goals, but there are many ways to achieve similar results. If you have other proven techniques, please share them in the comments section.

Initial cleanup. Fill a bowl with warm water mixed with standard dish soap and completely submerge the tuners in the soapy solution. Let them soak for an hour. Then, with the tuners still in the bowl, brush them thoroughly with a soft toothbrush. (You might be shocked by the water’s color.) Finally, carefully rinse the tuners under cold running water.

Old tuners get stuck because, in the past, they were lubricated with grease rather than oil. Over the decades grease solidifies, especially when the tuners aren’t in regular use.

If you have access to an ultrasonic cleaner—a device typically used to clean eyeglasses, jewelry, and watches—put the tuners into it, fill it up with water and some liquid cleaner, and run the device for 90 seconds. You don’t need a professional unit for this; any consumer model will do.

Now try turning each tuner to see if its buttons will turn. Often these two steps are all that’s required to get the gears moving again. Never force a tuner to turn because chances are good you’ll break off its button or damage the gears.

In this case, only one of the six tuners came unstuck—the others remained immobile. So it was time to bring in the big guns.

Dissolving the hardened grease. Get a hair dryer and a can of naphtha, and lay out some newspapers. A chemical pipette will also be very helpful, but if that’s not available, a small spoon will do.

A word of warning: Naphtha is highly flammable and you shouldn’t inhale its vapors, so wear gloves, goggles, and work outside or by an open window if possible. If not, wear a safety mask or respirator. Oh yeah—keep a working fire extinguisher handy.

Photo 2 — Photo courtesy of

Warm up the tuners with the hair dryer—this will speed up the deep cleaning process. Once the tuners are warm, put them on the newspaper with their shafts facing upwards and drip the naphtha into them (Photo 2). If you’re working with vintage tuners, be sure to prevent the naphtha from contacting the buttons. Older, pre-plastic materials can disintegrate if they come in contact with naphtha or any other solvents.

Repeat this process several times, and then try to turn the tuner shafts. Sometimes it takes several shots of naphtha to coax tuners back to life. In this case, the remaining five tuners came loose and could be turned again. But if any of your tuners don’t budge, grab the bowl you used previously and put the tuners in it with the buttons facing upwards. Now pour naphtha into the bowl until the tuner gears are submerged. Again, if you’re working with vintage buttons, don’t let the naphtha touch them. Soak the gears for a while, then remove them from the bowl, dry them with a paper towel, and see if they turn.

Old tuners get stuck because, in the past, they were lubricated with grease rather than oil. Over the decades grease solidifies, especially when the tuners aren’t in regular use. Naphtha dissolves the hardened grease, allowing the gears to turn freely again.

Look sharp! Once the tuners are back in working condition, it’s time to enhance their visual appearance. Brass tarnishes over time (this can range from a little patina to almost black), and you’ll likely see some verdigris on brass parts if they’ve been subjected to moisture. You’ll face a similar situation with vintage nickel tuners and hardware because, like brass, nickel can also build up a cloudy patina.

At this point you need to make a decision: Do you like to have some patina left on the tuners or do you want them to shine like new? Remember, if you decide to retain some patina, you can always change your mind down the road and polish them until they shine like new, which is what my customer requested. We’ll look at both procedures, starting with how to clean the tuners while retaining some natural patina.

To keep some patina on the brass, you’ll need a glass, as well as salt, flour, and vinegar. Put a tablespoon of salt and a tablespoon of flour into the glass and mix them thoroughly. Now pour vinegar into the glass, while stirring the mixture. The goal is to create a creamy paste, so add the vinegar slowly. If the mixture becomes too liquid, it won’t work properly. In that case, simply add some flour to thicken the solution and mix it up once more. It’s a good idea to wear gloves and goggles and, again, work outside if you can because this paste smells pretty rank.