David, I have used this technique on over a dozen pianos so far, maybe almost two dozen, I would have to go back and check my records. Allow me to share my experience and my hardly scientific conclusions. I am not set up with the equipment or the know how to really investigate this method in any scientific manner so take my observations with that big grain of salt. The first two pianos I applied epoxy to were a very small (maybe 4 1/2') grand and a very old (1880's) upright of unknown vintage both with much greater sentimental value than economic. I put on two thin coats of epoxy, sanded smooth and finished normally. The boards were dry to about 6% EMC. The end result was very pleasing on two fronts: 1)the tonal output for both pianos was much greater than I would have expected. Having rebuilt countless of these things without the epoxy I had certain expectations that were modest compared to the result. The other surprise was the tuning stability. Both pianos are more stable than I would have expected based upon previous experience, they don't fluctuate nearly as much as one would expect with the seasonal changes. Based upon the above experience I have continued to apply epoxy to every soundboard which doesn't get replaced and have see the same patterns emerge. I have found also better results when the epoxy is applied when the board is some what dry, in the +/- 6% EMC range. As far as crown goes, we may gain a small amount, but I will let my ears determine the success or failure first befor I pull out my string. So far I have not found a problem with this technique, so until something comes up my plan is to contiune to use it. So far I am happy with the results. I hope this helps. Feel free to email me privately if you would like. Andrew Remillard
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