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  • Anna
    Anna Lea

    Hi, I know with the air drying out in my home with the heat on during the winter I probably need to buy a humidifier for my harps but I need advice on what type works best.  Any advice?  Thanks, Anna

    replies to "humidifiers"
    • Liam
      Liam M


      I am in a very dry climate and monitor humidity closely. (The Intelli IMT-301 tuner that I use has a temperature and humidity readout)

      I use simple soap dishes with holes in the cover and wet sponges inside. I leave them inside the soundbox and inside any cover I have on the harps at the time. I see no damage has occurred to my harps from dryness, although some of our wood furniture has developed cracking. I have to assume the soapdishes are working.


    • Chris
      Chris Asmann

      Hi Anna.

      I wrote about my situation and the humidifiers I use here:


      There is also information on that thread from Howard Bryan and Carl Swanson.


    • Liam
      Liam M


      I know Chris means well, however.

      Before you spend a lot of money on something that may not be necessary, carefully inspect the wooden furniture in the room where your harp resides. It is subject to the same effects of humidity, (or in this case, aridity), as your harp. As it has been there longer, it will provide you a good indication of the severity of the problem you face. As well, ask furniture shops and stringed instrument shops in you area. Talk with the service technicians.

      I live in the driest climate in the United States. It currently is 21% humidity here. With the simple soap dish humidifiers, my harps are currently at 53%, 51% an 56% humidity. That includes the one in my shop undergoing restoration. I am constantly building cabinetry, furniture and instruments. I use glue joints extensively, abhor nails and detest screws.

      As I said before, I carefully monitor the condition of my harps and other wooden items in my home. While my harps get the soap dish humidifiers, some of my pieces of furniture have  small tupperware bowls of water placed strategically under them. I am not seeing an issue with damage from aridity.

      As to the issue of raw wood inside the sound box...... I am rather perplexed by this, irrespective of the humidity source, both the inside of the instrument and the outside are exposed to this humidity. The finished outer surfaces will prevent, or slow down the permeation of moisture into the wood in any event. So it becomes obvious that the moisture the wood absorbs is primarily coming from the inside of the instrument. I would not, however, leave just a raw soaked sponge inside of a soundbox. 

      I am sure many will disagree. Paradigms exist and they are difficult to overcome, but I truly hate to see someone spend money on apparatus when they could spend it on sheet music or another instrument.

      If you do decide on the humidifier concept, then I would strongly suggest this approach, http://www.cornerhardware.com/how_to_articles/installing_a_whole-house_humidifier/081   You will find it less expensive, intrusive and you gain the benefit of your entire home being humidified.

      My previous home here in Arizona had what they call a "swamping unit", an evaporative cooler. Humidity was steady @ 50% when we ran it. Our current home has a refrigerant system. I have investigated the total system humidifiers, but decided against it because we run ~ 60% of the year with neither heat nor AC running. But I see where it might be an answer to your case and would not require the continual attention mandated by both the soap dish and the portable humidifier approaches.


    • Anna
      Anna Lea

      I want to thank both Chris & Liam for your very helpful advice and for taking time out of your busy schedules to answer my question.  I am still considering how to handle this but think I will certainly give Liam's advice a try, especially since I have my harps in different rooms; this way I won't have to move one or both to have them together.  Thanks again.  Anna

    • Emma
      Emma Preuss


      While we're on the subject of humidity, I was wondering if I could ask a question.

      My current house suffers from damp a lot in the winter and so I have to occasionally use a dehumidifier. Is there any danger of this being an issue for the harp?

    • Liam
      Liam M

      Yes there is. 


      Wood is composed of cellulose fiber structures that absorb and evaporate moisture depending on the relative humidity of the environment they are located in.  The absorbed moisture causes a swelling of the wood and the evaporation causes a shrinkages.


      Two areas are particularly vulnerable to damage from this effect.


      First is swelling can cause structural cracking if the wood is not free to expand. Shrinking can also cause cracking when the wood is not free to contract.

      Second is glue joints which will seperate due to the stresses.

      Obviously, harps and other wooden structures are not intended to swell and contract.

      A indicator is to carefully inspect your wooden furniture which has been in the environment for some time. Look closely at all glued joints, (Like where the decorative coweling of chair backs joins the seat).  Also look at wooden door panels and framing, check the joints. 


      Your problem is the reverse of my own, I am not sure that even the word "Damp" exists in the Arizona desert vocabulary. I would think your heating system should compensate for the dampness you describe, but obviously not.  And the problem is exacerbated by changes, which you appear to be experiencing. I would start monitoring my humidity carefully. The tuner I mentioned previously has an built in function to do this.


      Within reason,(Obviously the extremes are to be avoided), it is maintaining a steady humidity that you are trying to acchieve.

    • Carl
      Carl Swanson

      I have to say I'm baffled by the above posts. I don't believe that a soap dish with a wet sponge is sufficient to humidify a whole harp. Neither is a dampit, which some of you occasionally mention here.

      With any humidification system, the humidity is going to be highest nearest the humidifier, and will go down considerably the further you get from the source. Soap dish humidifiers or dampits placed inside the body(soundbox) will raise the humidity there an no where else. That's why a larger humidfier, such as the type I have mentioned numerous times on these pages, is needed. You need to humidify the whole environment that the harp is in. In a perfect world, the harp would always be in an environment where the relative humidity stays in the range of 40% to 60% year round. In those areas of the country where this is the case, mainly the west coast and the southeast, I never see the kind of structural damage on harps that I see in instruments in the Northeast and central US.

      Looking at furniture is not a good indicator of how wood is reacting to the climate. Furniture(chairs, tables, etc.) can expand and contract quite a bit without resulting in cracking. Secondly, furniture does not have a ton and a half of pressure on it.

      Too much humidity, and especially uneven high humidity, can cause problems as well. I have seen harps that have been stored in damp basements, and the lower parts of the instrument were all but destroyed by the dampness from standing on a cement floor.

    • Liam
      Liam M


      Take a soap dish and place it under you harp cover. Leave it for overnight and then return to read the humidity under the cover with a hygrometer. Perhaps that will relieve your bafflement and you will believe the results you can see with your own eyes.

      As to furniture, fine furniture certainly is indicative of aridity damage, while it may not have "a ton and a half", (even with every string at the high end of tension, a 47 string harp would fall short of "a ton and a half", but it was quite dramatic), it is subject to repeated stress changes which are even more damaging then the steady distributed pull of the strings.

      Carl, I am quite offended by the attack and feel it to be quite inappropriate.  By trade I am a process control engineer intimate with the measurement techniques and control of many different variables, including humidity. To relax, I work with wood in a very dry climate. As an engineer, I have scientifically approached this problem and am sharing my results. I have even provided the specific model of instrument I am using to make my measurements. You have provided unsupported opinion.

      I will say nothing further on this subject. You, Carl, may believe whatever you wish. But I would suggest you reconsider your approach to others when you disagree.

    • Carl
      Carl Swanson

      You may be a control engineer, but I'm a harp repairman with over 30 years experience in what happens to harps under various conditions. I've seen thousands of harps of every conceivable make and age in every conceivable climate, and I've carefully observed what happens to instruments.

      When a harp is in an environment where the yearly cycle goes from moderately humid/very humid during the summer, to dry/extremely dry during the winter, then all kinds of damage shows up. At the very least, such instruments go out of regulation when the humidity change occurs. The finish can alligator, crackle, or fracture(depending on the type of finish on the harp), glue joints can open up, and laminations, such as are found in the hoop where the pedal slots are, can delaminate. I've repaired all of this damage many times.

      The problem of base frames coming out the bottom of the instrument is epidemic in a certain make of harp, and I've repaired hundreds of them over my career. While the company whose harps do this screwed up the engineering many years ago, setting the base frame up for failure, still, I never see slipped base frames in climates where the humidity is 40% to 60% year round, nor where people humidify their harps in the winter months. My own Lyon & healy harp, serial number 300 and built around 1898, which I completely rebuilt about 23 years ago now, looks brand new, with a shiny uncrackled finish, because I'm very careful to humidify every winter. The base frame on that harp, which had to be replaced as part of the rebuilding, is in exactly the place where I installed it, again, because the harp has been in a humidified environment.

      No harpist is going to put a cover on the harp every night and stick a soap dish inside. And even if they did, what is going to happen every day when they take the cover off? The harp will go from a 15% to 20% humidity during the day to 40% to 60% at night. That may work for an accordion, but not a harp.

      Quality musical instrument wood is dried to a 5% to 8% moisture content in the United States, and is probably the world standard now. If you buy such wood in your area, let it sit around for a reasonable amount of time, build an instrument out of it in that climate, and keep it there, then the instrument is in a very stable(dry) environment year round. The wood is very dry, the climate is very dry year round. No problem. What do you suppose is going to happen to a harp built in a humid summer environment in Chicago or Europe for example and then shipped to a very dry climate like yours? Despite the best efforts of the manufacturer to keep things dry, I'm sure there will be changes to the instrument with the move.

      I was not attacking you or your scientific measurements. I was simply pointing out that it is impractical and in my experience falls far short of what is needed to keep a harp in good workable condition.

    • Sid
      Sid Humphreys

      Really the best thing I ever did for my harp was purchase a  Quiet Care Honeywell humidifyer. The harp held it's tune wonderfully and there was much less string breakage last winter. Another positive effect of the humidifyer was no more static electricity in my wool clothes and blankets, and to boot, no dry skin!

    • Sid
      Sid Humphreys

      I should also add to this post, that living in Dallas Texas, our temperature varies ALOT in the winter. Last week we had lows in the 20's with highs in the 30's. Today is moderately cool but tomorrow will be in the 70's. I didn't have my humidifier on the first night it became cold and the humidity in my house went from 46% that evening to 28% the next morning. My humidifier will automatically kick off when it reaches a certain level of humidity so I don't have to worry about getting to damp in the room.

      Liam, I'm glad you found an inexpensive way to solve your arid problem, but I don't think my insurance company would be very sympathetic if the damp sponge didn't work. No offence please, but after spending tens of thousands on a pedal harp (even more if it's gilt) what's another 100 dollars to keep it in good condition?

    • Liam
      Liam M


      There is no "may be", I am a process control engineer. I respect your profession and I insist that you respect mine.

      You are conveniently overlooking the fact that I did recommend a TOTAL HOME HUMIDIFIER to Anna and provided her a link to a supplier of same. The soap dish humidifier, and "dampits", are not ideal solutions... and they certainly are not elegant and expensive. But they are quite reasonable stopgap measures when more elaborate systems are neither available nor practical.

      As well, you overlook the fact that the moisture content transition for the harp is far slower then you imply by your night/day scenario. While the harp's environment will indeed change from 15 to 20% to 40 to 60% humidity, the moisture content of the wood of the harp will not change that fast. It simply does not occur that rapidly. If it did then I dare say few harpists would ever be willing to subject their instruments to the rigors of gigs. How many concert halls & stages have climate control?  Additionally Carl, you refer to musical instrument quality wood dried to 5-8% moisture content. Were your day night scenario valid, that process would be very rapid and would be lost the minute the wood left the kiln to be shipped.

      I have no doubt that you have seen considerable damage and I applaud your experience. However, I have yet to see where you are offering the first scintilla of evidence of scientific observation. And your method of pointing out things has all the attributes of an attack irrespective of your denials. Once again, I find it highly inappropriate and I most certainly take umbrage.

    • Zep
      Zep of the Cross Strung

      Hi to all,

      I'm going to list some of what I think I know, based on the above discussion.  If my reasoning or assumptions are wrong, I'd appreciate knowing.

      1. If you have a very expensive instrument in an environment where the relative humidity exceeds known safe parameters (40-60%), your best bet is an humidifier, either of the whole-house variety, or the room variety.
      2. The sponge approach might work if used with a waterproof cover that was generally left on the harp, and with a calibrated humidifier that demonstrates that you're instrument is consistently in the 40%-60% range.  This seems like an empirical question - either such an approach would have the desired effect, or it would not.  It seems like it would be easy to test.  Even if it were ok, if I had an expensive pedal harp, I'd still want a room or whole-house humidifier.
      3. Loss of moisture from wood or glue joints is a slow process over days or months, not hours.  I assume the effect, therefore, is cumulative.  But, if you re-humidify before obvious damage is done, is it reversible?
      4. I understand that many expensive string instruments (e.g., violins, guitars, cellos) are preserved using a dampit-type humidifying arrangement, but that they are also typically left within their cases.
      I recently tried to calibrate my digital hygrometer using the "salt" method.  This indicated that my hygrometer was reading 12 points of relative humidity too low!  (so, when it read "36" the true relative humidity was "48.")  Is the salt method of calibration valid?  Here's a link for a typical procedure:

      hygrometer calibration, salt method


    • Liam
      Liam M

      I like that salt technique Michael, intriguing. (you've done it again, now I will be studying that to fully understand the physics involved).

      I have a sling psychrometer which uses red spirit alcohol that I check against. My dig hygrometer has a 2% error which I factor in... also I have learned to wait for the settle before I take my readings. And I have the advantage of frequenting industrial calibration laboratories where I can have my instruments checked for free.

      My experience tells me glue damage is irreversible, but your point of obvious damage raises the question of where on the aridity progression the damage actually occurs?

      Whole house humidifying is definitely the preferred option. But as our climate allows us to open our house to the atmosphere, it just would not be worth it for the limited time we are closed up.

      I can understand as you say with a 5 digit pedal harp, one could definitely consider dedicating a room and humidifier to it.  Of course with a 5 digit harp. I believe I would also be covering it on a regular basis when not in use in any event.

      I know some of the pieces we brought with us from Venezuela have truly suffered and it was for their sake I started closely attending the humidity issue. In my shop I use old plastic drop cloths to cover work with wet basins alongside the piece. Of course I also am protecting from saw dust that gets in everywhere in a shop. In the house, I found those fancy shower curtains are inexpensive, attractive and cover instruments well. 

    • Saul
      Saul Davis Zlatkovski

      Well, I have entirely given up on humidifiers. What used to be a reliable brand, Bionaire, was bought up and ruined. Anything they put out now requires a ridiculous amount of maintenance and the constant purchasing of additional products to keep it from getting moldy or otherwise contaminated.

      My solution has been to use a vaporizer. They require minimal maintenance, and in a large high-ceilinged room like my studio, there is no hazard from warm vapor. After a couple of days, it has raised the humidity enough to help.

      Sponges get dirty, so I would prefer to hang up wet towels and let them dry.

    • Zep
      Zep of the Cross Strung

      Here's an article on humidifiers from Consumers Reports.  No ratings, just info.

      Consumer reports humidifier info


    • Anna
      Anna Lea

      I certainly didn't intend to start such a controversy, but thanks to everyone for your advice.  I would like to ask Carl a question, you seemed to indicate terrible problems from storing harps in basement rooms, is that alway the case?  I was thinking of putting my harps in a finished basement room so they could all be together.  Bad idea??