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Why Do Piano Keys Stick – 5 Common Reasons

Have you found yourself playing a wonderful piece of music only to run into a sticky piano key? It’s actually a really common problem that pianists run into; especially with older instruments. If you’re in the middle of a recital it’s even worse to deal with. Perhaps you’re dealing with a piano key sticking right now and aren’t sure how to fix it. I’ll explain why they stick next and then ways to fix and prevent the issue from happening in the first place.

Piano keys stick for a number of reasons. The most common cause of sticky piano keys is the key slip being too close to the front of the white keys. Objects like coins and trash lodged underneath the keys, dirty rail pins, and broken hammer parts. Built up moisture also has a significant effect on keys sticking or moving fluidly. 

Why Do Piano Keys Stick

Diagnosing A Sticky Piano Key

As you can see there are a number of reasons why a piano key might start sticking. Because of that it’s easy to waste a lot of time just trying to figure out what it may be. I’ve had this happen to my pianos before and have wasted time too.

Once you figure out how your piano works and check a few things off, you can easily get to the bottom of things.

First begin thinking about when your piano keys started sticking. Doing this allows you to assess what changed during that period of time. Was the air conditioning hotter than usual?

Perhaps you notice that favorite repertoire pencil went missing? Maybe you left a few objects on the piano one day or leaned up against it. Asking yourself those questions is a good start to assessing what went wrong. If I were you I would begin with the key slip and work up from there.

Should You Hire A Piano Technician?

I know it can be a little scary dealing with mechanical issues when it comes to the piano. With all of the practice and performing that novice and even professional pianists do that’s understandable.

Sometimes as pianists we get a little anxious because we think something has gone terribly wrong with the instrument. Maybe we were banging on the keys too hard one day, or got careless with the temperature in the room.

piano technician

With key sticking it’s typically a small issue, so you can rest easy. In fact, you the pianist can fix it yourself most of the time. When you really don’t know what’s going on though then it’s time to hire a piano technician to get the job done for you. The great thing about this is that piano tuners and technicians are typically one in the same.

It’s a bad idea to take your piano completely apart and start messing around with the hammers and and mechanisms. That kind of work requires the right kinds of tools and screws and gentle care so nothing breaks. That’s where a technician can really be helpful.

5 Common Reasons Piano Keys Stick And How To Fix Them

Next I’m going to go over 5 common reasons why piano keys stick and how to fix them. Of the reasons listed below there’s only one where I suggest you get a technician involved to help you fix the issue. Let’s start with the most common issue first; the key slip.

Fixing The Key Slip

The key slip is an important piece to the instrument casing. It houses the front part of the piano keys and helps protect dust and other objects from getting underneath them. During routine piano maintenance or simply leaning against that key slip, sometimes it can get jammed up against the white keys.

When this happens you’ll start experiencing sticking keys. Sometimes this can be one key, but I’ve found that several keys stick in this case. Since the key slip is one long piece of wood, it’ll have an even impact across the board in most cases.

Fixing the key slip is quite easy. To remove it you’ll want to unscrew the two key blocks located at both ends of the key slip. Those screws can be found underneath the piano, so you may need to squat down to see them. Once you remove the blocks gently work the key slip out. Check for any dust or objects while you’re there and then reinstall it.

In case you’re wondering, the blocks are there to hold the entire keyboard in place so it doesn’t move around. Since they sit on both ends of the key slip it can actually end up squeezing the wood against the front of your key frame which causes sluggish sticky keys. The key to a successful reinstall is making sure those key blocks are not screwed in too tightly.

Removing Objects And Trash

The other common problem I’ve run across with older pianos in particular are objects and trash inside the instrument. Usually these are paper clips, coins, pencils and even sheet music! It’s very easy for things to fall into a piano when you’re not looking. Practice pianos at schools, churches and under frequent use will most likely have this issue.

When the fall board is raised you’ll notice a small gap there. It might not look like much, but it’s certainly wide enough for objects of all sizes to fall into. Heck, I’ve even dropped large pages of sheet music behind the fall board before, so it’s quite common for this to happen.

To clean the trash out simply lift up the fall board gently and wiggle it out of place. Be careful not to bump the keys or sides of the instrument as you remove it. Right away you’ll be able to see any and everything that’s fallen into the action of the instrument.

What I do first is grab a dry cloth and wipe down all of the dust and loose papers. If you want a small hand vacuum is useful for blowing out those hard to reach pieces of paper and lint that may be in there as well.

The other location objects may have slipped down into are actually underneath the keys where the rail pins are. In this case consider also removing the key slip and having a look underneath there with a flashlight.

Lubricating Dirty Rail Pins

The more a piano is played the more maintenance it will need. An often overlooked issue that slows down the action and in some cases causes a key to stick is a dirty rail pin. The keys sit on the front rail pin which has a bushing on it as well.

piano rail pins

Over time that pin will begin to rust, so I would check that first. If you see rust clean it off with a soft cloth, making sure to work away any debris. Just doing that will instantly free up your keys to move up and down the pin with ease. Also make sure to check the balance rail pins which are located further back on each wooden extension of the piano key.

After the rail pins are cleaned off it’s time to lubricate the pins. There’s all kinds of lubricant out there, but I personally use Protek. It’s a safe and odorless lubricant that doesn’t damage the wood of the instrument which is crucial. The lubricant is also long lasting and doesn’t dry out fast. Protek comes in wide nozzle bottle, so for those hard to reach spots I would use a medicine dropper or something to that effect.

Take a few drops of the lubricant and drop it down each front rail pin and balance pin. Overall this might take 10 minutes or so to do. Give the keys a little bit of play and see how they feel. If it’s still a little sluggish consider adding some more lubricant and let it settle. Whenever my keys start to stiffen up I just apply the lubricant and it works great.

Ultimately if the rail pins are completely corroded and beyond cleaning and lubrication then you need to replace them. This is not something I would do on your own, so a piano technician would be worth it here.

Your first instinct might be to just replace the pins that are corroded, but for consistency I recommend replacing them all. You can typically get a complete set of piano rail pins for under $50 from most piano parts suppliers.

Fixing Broken Hammer Parts

Over time things get loose, work there way out of place, bend and yes even break inside the piano. When it comes to key sticking the last place I look is at the hammers. If you take off the fall board you can usually get a good look at what exactly those hammers are doing.

Perhaps it’s not traveling far enough to the string, or maybe the hammer elbow is moving awkwardly. I’ve played some pianos where screws have fallen out of place and more too. If you can get a good look at the hammer butt and flange then the cause of your issues are likely there. The flanges have metal pins in them and at times those can be too tight or too loose.

An issue like that is hard to diagnose, but it can totally slow up the entire action of that individual key to the point that it sticks. Bent springs and corroded hammer parts are also potential causes.

When it comes to anything with the hammers or really delicate parts of the piano I just won’t touch it. It’s just too easy to break those parts, and they can get pretty expensive. It’s not worth digging inside the instrument, taking something completely out of place and then having no ability to reinstall it properly. If you suspect the hammers are having issues then definitely call a piano technician.

Dealing With Moisture

Moisture levels in the air can have a tremendous affect on your instrument. This goes beyond just how your instrument sounds, but also how it performs too. When the humidity levels are higher your piano can experience swelling of the wood.

When this happens things start to work themselves out of place. Swollen keys can happen in really extreme situations especially, which almost certainly will be the reason the key is sticking.

You can actually attempt to fix this without buying new piano keys though. Depress the key and then stick a coin or screw driver in between. By adding a little pressure and wiggling you can properly space the keys back to their normal place. This works for white and black keys too, just be careful not to chip it and be gentle.

Piano humidifier systems is perfect when you need constant temperature regulation. In a hot southern environment like Florida especially, a humidifier like this will save you on having to constantly tune the piano, dealing with wood swelling and parts getting messed up. For big pianos over 6′ I recommend a humidifier system. Also if the piano is in a room with poor circulation or near an air vent you’ll want one of these too.

Final Thoughts

Those are the 5 most common reasons why your piano keys might be sticking. Most of them are really easy to diagnose, but not all of them are easy to address. When it comes to humidity levels definitely consider installing a humidifier on the instrument so it remains consistent with it’s action and performance.

With delicate parts on the inside I don’t suggest you try to fix that on your own. Unless you have a great understanding of how each piano part is built for that particular instrument you will likely end up doing more damage. What you can do is reach out to your piano tuner or technician and get a quote on fixing it.

Since piano keys sticking is a relatively common problem, the fix is usually quick even for a piano technician (unless they are replacing entire sections of your instrument). Whenever I get work done on my instrument it’s no more than $25 or more for the fix. They’ll even carry the lubricants and some spare parts along with them too if you want them to just take care of the whole thing for you.