Rust and corrosion
CAR-08Why do handpans rust, and what makes it worse?#
beginner
Short answer. Most handpans are made from carbon steel, which rusts whenever water and oxygen reach bare metal. Sweat, humidity, salt air and trapped moisture in a closed case are the four things that reliably make it worse.Rust is iron oxidising in the presence of water and oxygen. Nothing exotic is required, only moisture and time. Handpans are unusually exposed for a steel object because the whole playing surface is bare metal that gets handled, and the treatments makers apply (nitriding, oil, wax, occasionally paint) all work by keeping water away from iron rather than by making the iron immune.
The accelerators, roughly in order of how much trouble they cause in practice:
Sweat. Warm, salty and slightly acidic, applied directly by hand, every session. See CAR-02. This is the leading cause on instruments that are played regularly and wiped rarely.
Humidity. Above roughly 60 per cent relative humidity, corrosion of bare steel speeds up markedly, and it gets worse the higher you go. Damp basements, bathrooms, unheated garages, tropical and monsoon climates and any room where washing dries are all bad homes for a handpan.
Salt in the air. Coastal living is genuinely harder on handpans. Airborne chloride settles on every surface, and chloride ions break down protective layers and drive localised pitting. Makers who live near the sea and makers who ship there both say the same thing: shorten your oiling interval, wipe more often, and keep the instrument away from open windows facing the water. Playing on a beach and then putting the instrument straight in a case is close to a worst case.
Trapped moisture. A closed case is a sealed humid box. Foam absorbs and holds water, and an instrument put away warm and damp sits in its own condensation for hours. This is why so many guides tell you not to store a handpan permanently in its case, and why a moisture absorber in the case is a cheap piece of insurance if you must.
Two smaller ones worth naming: standing water from a drink or rain, which needs drying immediately rather than eventually, and skin contact from bare legs and forearms on the bottom shell, which is the surface people forget to wipe.
CAR-09How do I spot rust early?#
beginner
Short answer. Look at the instrument in strong, raking light every few weeks, and check the places you never wipe: the underside, the rim, under any rubber ring, around the port, and any spot that rests on case foam. Early rust is a faint orange or brown speckle or a slightly rough patch, not an obvious red stain.The reason to look deliberately rather than casually is that surface rust starts as tiny points that are almost invisible under diffuse room light and obvious under a light held at a low angle. Tilt the instrument, catch the light across the surface, and look for anything that breaks the uniform colour: speckling, a dull matte patch in a glossy field, a change in texture under a fingertip. Nitrided instruments are usually dark grey to black, so early rust shows as a warm brown tinge rather than bright orange, which is easy to mistake for a smear of oil.
The high risk sites, in the order they usually catch people out:
- Underneath the rim and beneath any rubber or silicone rim ring, where moisture is held against steel with no airflow.
- The gu port edge and the inside surface around it, which collects damp and is rarely treated.
- The bottom shell where it sits on your knees, on foam, or on a stand pad.
- The inside of the instrument, on raw or lightly treated carbon steel builds. You cannot see much through the port, but a torch and a phone camera will show the worst of it.
- Any point where the finish has been scratched through, which becomes a corrosion site quickly.
Touch is a good second sense. Run a clean, dry fingertip over a suspect area. Healthy treated steel feels smooth and slightly slick. Early corrosion feels faintly gritty, like very fine sandpaper, before it looks like anything at all.
Catching it at the speckle stage matters because a light surface bloom wipes away with alcohol and a re-oil, while pitted rust has eaten into the metal and cannot be undone. On nitrided steel in particular, neglected surface rust progresses into deep pitted patches that permanently mark the instrument, which is exactly the failure mode makers warn about.
CAR-10How do I remove light surface rust without detuning the instrument?#
intermediate
Short answer. Clean with isopropyl alcohol first, then work only the affected spot with the gentlest abrasive that will shift it, using light hand pressure and no hammering. Re-clean and re-oil afterwards. Hand rubbing does not detune a handpan; impact and heavy force do.Take the reassurance first, because it is the part people get wrong. Tuning lives in the shape and tension of the steel, and gentle rubbing with a cloth or a fine pad does not change either. What detunes an instrument is a blow, a press hard enough to deform the metal, or heat. So do not lean your bodyweight on a tone field, do not use a power tool, a wire brush, a drill attachment or a sander, and do not tap anything with a hammer. Rub, do not push.
A sensible escalation, stopping as soon as the rust is gone:
- Alcohol and a soft cloth. Isopropyl alcohol or surgical spirit removes the old oil film and, surprisingly often, the discolouration you thought was rust. Try this alone first.
- A fine non woven abrasive pad, used dry or barely damp. Ultrafine grey pads are the usual recommendation, and Ayasa name exactly that for spot treating rust on their instruments. Work in small circles with very light pressure.
- A polishing cloth impregnated with a mild compound, which some guides prefer to a pad because it is gentler and more controllable.
- 0000 grade steel wool, which appears in some published guides but is the option to be most careful with. It is aggressive on surface colour, and it sheds fine steel particles which will themselves rust if you leave them on the instrument or in the port. If you use it, remove every trace afterwards.
Then clean the area again with alcohol to remove residue and abrasive dust, and re-oil or re-wax the whole instrument, not just the patch.
The honest warning: every abrasive step removes some of the surface treatment along with the rust. On nitrided steel that means removing colour, and the pale patch you create does not darken back. Guides that recommend green scouring pads and polishing cloths say this openly. You are trading cosmetics for stopping the corrosion, which is usually the right trade, but go gently and accept a faint mark rather than scrubbing until it looks perfect.
Never use acetone, which can attack finishes and the adhesive bonding the shells, and never use chloride based cleaners or rust removers formulated for cars unless your maker specifically approves the product.
CAR-11When is rust serious enough to need a maker?#
intermediate
Short answer. When it is pitted rather than powdery, when it covers large areas, when it is inside the shell, when it flakes or lifts, or when the instrument has started to sound different. Surface bloom is a home job. Anything that has eaten into the metal is not.The distinction that matters is between rust sitting on the steel and rust that has consumed some. Light surface rust wipes to a brown smear on your cloth and leaves smooth metal behind. Pitted rust leaves visible craters, feels rough after cleaning, and often reappears in the same spots within weeks because corrosion is still active below the surface you cleaned. That second case is a material loss problem, and no amount of oil fixes it.
Send it to a maker, or at least send them photographs and ask, when you see any of the following:
- Pitting you can feel with a fingernail, or dark spots that stay dark after cleaning.
- Rust across a whole tone field or a large part of the shell rather than isolated points.
- Significant rust inside the instrument. Interior corrosion on a carbon steel build can progress far before you notice it, and it is not something you can treat properly through the port.
- Flaking, lifting or blistering, which usually means the corrosion has undercut a coating.
- Rust at the seam or glue line, which is both a corrosion and a structural question.
- Any change in the sound accompanying the rust: lost sustain, a note gone flat, a new buzz.
What a maker can actually do is worth knowing before you ship anything. They can clean and neutralise properly, take the instrument back to bare metal where needed, re-treat or in some cases re-nitride, and retune afterwards, because aggressive rust work usually does shift the tuning. What they cannot do is put metal back. Deep pitting is permanent, and if it has thinned a tone field enough the note may never be as stable as it was. That is the reason to act at the speckle stage.
Cost and turnaround vary too much by maker, country and severity to quote. Ask for an assessment from photographs first, because for a badly corroded budget instrument the honest answer is sometimes that restoration costs more than the instrument is worth.
CAR-12Does nitrided or stainless steel rust?#
intermediate
Short answer. Nitrided steel is rust resistant, not rust proof, and it will corrode and pit if neglected. Stainless is far more resistant and is often described as virtually rustproof in normal use, but it can still spot in harsh conditions and it develops a cloudy patina that is cosmetic rather than harmful.Nitriding is a heat treatment that diffuses nitrogen into the surface of carbon steel, producing a hard nitride layer that resists corrosion much better than raw steel. It is a surface, though, and it is slightly porous, so it is not a sealed barrier. Makers who work in nitrided steel are consistent that these instruments need wiping after every session and periodic oiling or waxing, with intervals commonly quoted around every two to four weeks, and that neglected instruments develop deeply pitted rust patches over a few years. The porosity has a second consequence: a nitrided surface absorbs oil readily, and several makers report that an over oiled nitrided instrument loses a little sustain, which is why some prefer a wax on this steel.
Stainless steel resists corrosion for a different reason. Chromium in the alloy forms a thin passive oxide layer that reforms if it is scratched, so the protection is self healing and goes all the way through the material rather than sitting on top of it. In practice a stainless handpan can survive humidity and neglect that would ruin a nitrided one, and stainless owners typically oil for appearance rather than survival. Stainless is not magic, though: chloride rich environments, prolonged salt exposure and contamination from carbon steel particles can all produce spotting.
What stainless does do reliably is patinate. Skin oils and slow oxidation leave a cloudy, mottled look, often patchy where hands land most. Saraz describe this plainly as cosmetic, with no effect on sound or durability, and that matches general owner experience. Some players polish it back, many learn to like it.
There are other constructions in circulation, and they change the answer. Raw or untreated carbon steel needs oiling inside and out and rusts quickly if you forget. Painted, powder coated or lacquered instruments rely on that coating, are usually fine while it is intact, and rust rapidly wherever it chips. Ember steel and other proprietary treatments sit somewhere in this landscape and come with maker specific instructions.
Going deeper. Steel type is one of the genuine trade offs when buying, because corrosion resistance travels with a different sound. Nitrided instruments tend to have a crisper attack and shorter decay, stainless a longer sustain and more layered harmonics. Neither is better, and the care difference is a real part of the decision.
CAR-13Does rust change the sound?#
advanced
Short answer. Light surface rust is essentially inaudible. Heavy or pitted rust does change the sound, mostly by damping the surface and by removing metal, and by then the tuning may have moved too. If your instrument sounds different and looks rusty, treat the rust as a real cause rather than a coincidence.Start with the physics. A tone field is a thin, tensioned steel membrane whose pitch and partials depend on its geometry, its thickness, its stress state and how much energy the vibration loses to damping. A film of oxide a few microns thick barely touches any of those. That is why a lightly spotted instrument measures and sounds the same as it did, and why removing light rust does not restore some magical lost tone.
Heavy corrosion is different, and it acts through three mechanisms. First, damping: a thick, porous, flaky oxide layer is a lossy material bonded to a vibrating surface, and it converts vibration into heat. The audible result is shortened sustain and a duller, less ringing character. Second, mass and thickness loss: pitting removes metal unevenly across a tone field, and a membrane that is thinner in patches has different partial frequencies and often a less stable relationship between them, which can show up as a wobble or a note that will not sit still. Third, and least discussed, is the stress state. Corrosion attacking a highly stressed, work hardened surface can relax it locally, which is one reason very neglected instruments sometimes drift flat.
There is a fourth path that is not about the steel at all: what you do about the rust. Aggressive abrasive work, heat, or a maker taking the instrument back to bare metal all change tuning far more readily than the corrosion did. This is a common cause of the reported sequence of rust, then cleaning, then a note sounding wrong.
In practice, the useful diagnostic order is to check for damping and mechanical causes first (see TRB-04), because case foam contact and hand position explain far more sustain complaints than rust does. But if the instrument is visibly and extensively corroded and the sound has gone dull, believe your ears. That is the point at which a maker’s assessment is worth paying for.
See also: CAR-11, Acoustics and physics