This article appeared in the January 2003 Wippenpost
Why don’t my dampers damp or should I just add water?
Last month I touch on briefly on how added mass can improve the effectiveness of dampers. However I think I got the cart before the horse. Before discussing springless dampers I thought it might be helpful to share some of the reasons I have found for the lack of dampness in dampers. This list is by no means conclusive as I am sure tomorrow I will be once more stumped, nor is it in any particular order, however this is the series of tests I go through whenever I find a dampless damper.
1) Are the damper felts intact. It is pretty hard to get damaged dampers to work.
2) Does the damper lift and drop vertically or does it twist, roll, one end first, etc.? To work most effectively, dampers need to lift and drop squarely on all strings simultaneously. Corrective bends at the damper head, in the damper wire under the strings, and twisting the wire in the underlever will help with this problem.
3) Are the strings level. By all means don’t forget this one. If one of the strings is significantly below it’s partners, you will never get it quiet.
4) Are the trichord felts cut all the way through? I had to do this one today. Seems my knife was a little dull when I installed that little bugger. Sometimes adding a length of silk thread between the wedges will also help.
5) Are the felts over one inch long? I am no physicist and cannot get into the physics behind string nodes and the best place to dampen a string, however my experience has shown more and shorter blocks will generally work better than fewer and longer blocks.
6) Are there a number of short felts instead of a couple longer felts? Sometimes fewer and longer is better in which case No. 5 would be invalid. But experience and experimentation will give you the best answer as your results may vary.
7) Are the underlevers functioning properly? Are any unglued, broken, or otherwise dysfunctional? Well then fix them.
8) What kind of shape are the damperguides rail in? If the dampers wobble around a lot they will never come down the same place each time. Talk about hitting a moving target. I played a piano a while back where I could actually feel the damper wires bouncing around their guiderails, they were so loose. Rebushing the rails took care of the problem.
9) Are there block felts where there really should be trichord felts? Trichords are usually more effective dampers. In addition to the better dampening, running the trichords through the first dozen or so tenors and then block and trichords through another 8 - 12 notes will give the pianist a more subtle ¼ and ½ pedal.
10) Is the underlever spring in its slot? Is there sufficient tension on the spring? (Don’t put too much now.) Is it broken? Is there one at all? How does the tension vary from note to note? These are just some of the reasons I don’t like springs.