I have read with interest the many articles posted, and those in the
MMDigest Archives, about valve travel. I am presently working on a
later Duo-Art from around 1928 which has the circular valve seats,
not the cross-valve seats. The leather is amazing in very nice shape
and I know that it has never been restored before.
I have measured the valve travel of probably a dozen valves; it is
around 0.048" to 0.050". From what I've read this is blasphemy.
Assuming some depression of the leather valve facings where they
have seated for years, I calculated the valve travel based on the
distance between the 2 metal seats, and the thickest parts of the
valve where the leather did not appear compressed. I'm still coming
up with a relatively high valve travel of 0.044".
So now what? This is my first, and most likely only, Duo-Art
restoration. I'm at the mercy, and hopefully wisdom, of those who
have done more than that. Do I rebuild setting the travel as
measured, which by the way worked just fine, or lower it to 0.035"
and risk sluggish action? We are talking about less than 10-thousands
of an inch difference, but according to some, this is the difference
between an instrument that will play and one that just uses up energy.
Jim Quashnock
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