Although the damage to the piano in the picture at the right was caused by a severe accident or vandalism, a piano may have unseen damage from a variety of causes. Your piano tuner/technician can note any items of concern during regular tuning visits. Below are some potential issues and guidelines related to purchasing and maintaining your instrument.Issues:•Pre-purchase evaluation•Damage caused by cleaning sprays and chemicals•Cleaning and polishing the piano•Accidental or well-meaning lubricants•Humidity & temperature - damage and tuning instabilityIssue - Pre-purchase evaluationGuidelines- You should have a tuner/technician look over a used piano before purchasing one. I am often called to tune a used piano that was recently purchased and moved into someone’s home. In several cases, the piano was not worth moving and the new owner was unaware of serious issues with the condition of the instrument. The previous owner was either unaware of its condition or didn't want to pay to have it scrapped, so they gave it away. On the other hand, I've seen used pianos that were a terrific bargain. Most piano tuners cringe when they get a call to come tune a "free piano" since it could be in any condition. It's not a pleasant experience to tell someone that the instrument they just obtained is not repairable, without significant cost, or that it cannot be tuned.Considerations:•You don't necessarily avoid a used piano that needs some repairs. But a piano tuner/technician can provide an estimate of what it will take to restore it to good playable condition.•There are many items to be checked prior to purchase that you will not be able to detect yourself. These would include condition of: pitch (and related implications), pinblock, bridge, strings, pins, action, hammers, felt, pedals, regulation, sound board, humidity-related environmental issues, rodent damage, etc. It is well worth an evaluation fee to know you avoided a problem instrument.•There are some pianos that are no longer tunable due to age and conditions caused by temperature and humidity damage. A technician can tell you if the piano will be able to be tuned. Two of the most common issues are dryness (affecting tuning stability) and corrosion (as shown in the photo below).•Is the piano close to concert pitch (A=440). If not, that doesn't necessarily mean much other than it hasn't been tuned for a long time and will need a pitch-raise. But it could also indicate that the tuning pins are loose and the pinblock has dried out.•If the seller states that "it has been a few years since it was tuned", experience has revealed that this usually does NOT mean a literal duration of several years. It often indicates that it has been many years since the last tuning.• Generally speaking, the condition of a used piano will be discussed privately with the prospective purchaser once the instrument has been evaluated. There may be things to discuss that are between the technician and the prospective buyer that could contradict or offend the seller if discussed in their presence. The purchaser who is paying for the evaluation wants to make an informed decision. The owner / seller is not entitled to a free evaluation. However, if the prospective buyer wants to share the information with the seller, that is their choice.Issue - Damage caused by cleaning sprays and chemicalsGuidelines- It's great to keep your piano looking good, shiny and free of dust. But there have been piano owners haphazardly causing significant damage using cleaning and dusting sprays. A technician friend knew a customer who was determined to take good care of their new piano and dusted it several times a week using a common household dusting spray. Within about a year, enough spray had gotten into the pinblock around the tuning pins that the damage was permanent. The only solution was a new pin-block and tuning pins. The cost to repair would be in the thousands of dollars.Keep the following in mind:•Dusting spray on the piano, or even its use on furniture in the same room, will likely get into the tuning pins. This can cause pins to become loose and eventually the piano will not hold a tuning. Sprays such as Pledge or Liquid Gold may contain chemicals that will damage pianos or interact with an older piano finish. Do not use this type of product on the piano including the keys.•In addition to the impact on tuning pins, older pianos may have a finish that can become sticky from use of modern cleaning chemicals. (One of my customers had an older piano bench that became very sticky as a result of cleaning chemicals.)•For dusting and cleaning, a very small amount of white vinegar (e.g. a teaspoon of white vinegar in a spray bottle of water) is suggested by piano experts as a cleaning solution. Mixing in some Windex should be ok for cleaning keys. Windex contains some ammonia that should be fine. However, other brands of glass cleaner could have some other additives. Therefore we cannot speak confidently about the other brands.Issue - Cleaning and polishing the pianoGuidelines•Wash a new rag before use to remove any dyes or oils that may be in the cloth.•Do NOT use any cleaning spray or cleaning chemicals anywhere on or near the piano. These chemicals can find their way into the tuning pins and make the tuning unstable.•For dusting and cleaning, a very small amount of white vinegar (e.g. a teaspoon of white vinegar in a spray bottle of water) can be used as dusting spray. Spray onto the rag, then use to dust and remove fingerprints. (Fingerprints are especially visual distraction on the high-polish pianos.)•Some "micro-fiber" cleaning cloths may be somewhat abrasive and could dull a high-gloss polyester finishes. A soft cotton cloth may be better.•For old keys that have some dirt stuck on them, the vinegar solution tends to work. Mixing in some Windex should be OK for cleaning keys. Windex contains some ammonia that should be fine. However, other brands of glass cleaner could have some other additives. Therefore we cannot speak confidently about the other brands. There is also a special piano key cleaner (called "Key Brite") available specifically for cleaning piano keys.Issue - Accidental or well-meaning lubricantsGuidelines•Do NOT try to lubricate anything in or on your piano. There are a few parts where lubrication is necessary. But many lubricant types should NOT be used. Your technician knows what type of lubricant is appropriate and for which parts.•If the piano is close to the kitchen, note that when cooking bacon or anything greasy, the grease is easily carried through the air. If you smell the bacon, the grease is probably in the air and could be lubricating the tuning pins, especially in a grand piano. Use the fan/filter in your cooking hood to reduce this possibility.•Grease / lubricant should not be used near a piano. I had one customer, many years ago, try to remedy rusty looking strings and tuning pins by spraying WD-40 all over the pins and strings which ruined the piano. Check with your piano tuner before attempting to fix "sticky keys" yourself. Most of us would much rather give out free advice on the phone than see someone ruin their piano.•Your piano technician uses some special lubricants that are NOT petroleum-based. These special lubricants are specifically formulated for the piano industry and do not contain sticky lubricants or grease. This works great since most of the piano actions have moving parts where a metal pin turns in a felt-lined hole. The special lubricants lubricate this mechanism with a non-greasy lubricant that cleans the contact surface. It then evaporates away leaving the surfaces to move and function as designed with no sticky residue that will cause problems later. Issue - Humidity along with temperature is a top cause for piano damage and tuning instabilityGuidelines- To have a reasonable chance of being able to pass your piano on to future generations, humidity needs to be managed.Considerations:•Relative humidity should be maintained between 40 and 50 percent.•The best approach is to manage the building/room humidity. If you are not sure what your humidity level is, you can get a humidistat for roughly $10 that will help you keep an eye on it. Some of the newer communicating thermostats also have a built-in humidity sensor and some can even be read remotely via your cell phone.•A second approach is a room humidifier. You can obtain these for well under $100. Although some of these contain humidity sensors and automatic operation, you will probably want to keep an eye on the room humidity to see if you need to adjust the settings and fan speed.•A third approach is to have your piano technician install a "Dampp-Chaser" system inside your piano. These manage both high and low humidity automatically. However, you will need to add water to the internal container whenever the add-water light indicates. These are a bit pricy, but for an expensive instrument they are a good investment over the long term. GR Horst has become certified by the manufacturer as a trained installer of the Dampp-Chaser system.