How to Clean an Electronic Piano, Part II

If you’ve read Part I of our guide on how to clean an electronic piano, you’re familiar with the general technique. (Spoiler alert: Take everything out and then start cleaning.) In Part II, we’ll discuss how to tackle some more specific and serious messes.

First, some safety tips. Whenever you clean a large vintage piece like a Wurlitzer keyboard, wear gloves and a respirator mask. Remember that objects that are 40 or 50 years old have been through some things: they may have structural problems, or broken or bent parts, or just stray pieces of metal or wood splinters that you can easily cut yourself on. The best way to avoid getting hurt is to work methodically, in a well-lit spot, and to always be aware of where you’re putting your hands.

Even seemingly minor cuts can lead to dangerous infections, if the object or even your skin is dirty. If you do hurt yourself, stop what you’re doing and follow the appropriate first aid care for the injury.

Onto the messes.

Rust. The best product for removing rust is Evapo-Rust. Simply fill a container with Evapo-Rust, dip your rusty parts in it, and leave it for several hours or overnight. Cover whatever container you use so the Evapo-Rust doesn’t evaporate. You can save whatever is left and reuse it over and over until nothing is left but rusty sludge.

We’ve left parts soaking in Evapo-Rust for days without negative effects, but if you’re dipping a one-of-a-kind vintage item you’ll probably want to check on it regularly just to be on the safe side. (And, as with any product, you should spot-test before use.) If the rust wipes right off, you’re done; if the object is still rusty, leave it in longer.

Once the object is de-rusted to satisfaction, rinse it with water, dry it thoroughly and consider preserving it with a rust protector.

Evapo-Rust works great on chrome, and we use it on Wurlitzer legs often. But be careful when using it on painted objects, because it could take the paint off along with the rust. However, in some cases, the rust comes off first, so it could be worthwhile to spot test while watching the object closely. Otherwise, use a product with a paste consistency, like Maas Metal Polish, which will give you more control over where you de-rust. Note that Maas will also remove paint, so proceed carefully.

If the object is too large to dip, wrap it in shop towels soaked in Evapo-Rust, then wrap the whole thing in plastic wrap. The plastic wrap step is important because if the towels have to stay wet with Evapo-Rust for this technique to work. If the object is vertical, Evapo-Rust makes a gel that works similarly to the liquid but has a thicker consistency. In most cases, we prefer to work with the liquid form.

Rust eats metal, so if you see it, you can assume that, at minimum, the finish underneath is gone. Products like Evapo-Rust and Maas remove the rust, but obviously don’t apply anything in its place. If the surface is heavily rusted, be aware that you may end up with patches of bare metal and you should apply a rust preventative when you’re finished.

Some rusty things require special care. These include:

Transformers. If the rust is on the transformers, you can brush off any loose debris, but do not attempt to remove rust from transformers. Rust eats metal, so removing the rust creates vulnerabilities in the surface of the transformer, promoting undesirable eddy current losses. Although a rusty transformer isn’t exactly great news, a mild to moderate rust is rarely detrimental and in fact increases the transformer’s overall resistance, which tends to reduce eddy currents.

Faceplates and other screen-printed areas. In most cases, we avoid cleaning rust off faceplates or other screen-printed parts of an amp chassis. The screen-printing is often very fragile, and it’s very difficult to remove the rust consistently while avoiding the screen-printed areas. Sometimes even brushing against the screen printing can cause it to flake off. Only attempt de-rusting a faceplate if the screen printing is in good condition. Even then, spot-treat the rusted areas and never dip the entire faceplate.

Reeds and tines. When cleaning Wurlitzer reeds or Rhodes tines, it is important to avoid any methods that are extremely abrasive, because you could end up changing the pitch and timbre of the reed/tine. The best way to de-rust them is to gently soak them in Evapo-Rust. But, if you’re happy with the sound of the reeds, don’t de-rust them at all. That said, you should certainly make sure that no rust or other debris is allowing the reed to make contact with the pickup. Brushing the reeds lightly with a soft brush or using canned air is often sufficient to dislodge any minor particles that can short the reeds to the pickup.

Mold. Mold can only be truly removed from non-porous surfaces. If the mold is on a porous surface such as wood, you’ll have to remove all visible mold and then seal the wood with some sort of anti-fungicidal sealant to prevent the mold from growing back. However, if the mold is on a painted area of the Wurlitzer, it might not have spread past the paint layer. In this case, you can try killing the mold, then keeping an eye on it to ensure that it doesn’t return.

There are a variety of mold-killing chemicals, so consider the surface and choose one that is the least likely to damage it. Then, using your product of choice and a paper towel, clean up all visible mold. When you’re done, clean the area with a HEPA vacuum to take care of any spores that entered the environment.

If the mold was serious and spread across an area of bare wood, you may want to coat the affected area with a fungicidal sealant to prevent it from returning. If the mold is extensive, you may want to refinish the entire Wurlitzer. In this case, you should use a mold remediation primer to seal the area before painting. If it is necessary to refinish the interior, remember that the Wurlitzer has electrostatic paint on the inside that would need to be replaced.

Animal nests/droppings. Rodent urine and droppings are dangerous because they could be infected with hantavirus. However, hantavirus only survives in the environment for a few days. If the Wurlitzer has been stored for more than a week in an area you know to be free of rodents, your risk of hantavirus should be slim. Of course, you should still wear a respirator mask and gloves to protect yourself from dust.

To clean rodent nests or droppings, spray the area with disinfectant. Pick up the nest/droppings with a paper towel and dispose in a covered garbage can. Avoid vacuuming, because the suction may just agitate the dust and kick it up into the environment. Then, disinfect the surface. As always, work in a well-ventilated area.

Water damage. Some Wurlitzers show evidence of old water damage, including stained wooden parts. If the damage is superficial, most wooden parts can be sanded lightly, just past the stained area. Beware of sanding too deeply on sensitive areas like the keybed, because you could change the shape of it and detrimentally affect key depth and feel.

If possible, replace any parts that have suffered water damage. Felts, key bushings, and paper shims are easy to replace and will incidentally mitigate any weird mildew smells that your keyboard might have. Note that moisture can make the felts shrink or become compacted, which affects the piano’s playability. So, if in doubt, replace. We offer key bushing replacement kits here which are a perfect fit.

If the water damage is recent, ensure that everything has had a chance to thoroughly dry. If your Wurlitzer is in a humid or moist area, it may never get a chance to fully dry. You may need to remove the keys and/or keybed and moving any affected parts to a warm, dry spot.

Further Reading

Browse all of our articles on restoring vintage gear. Or, click on an image below.

Paulina Salmas