One option is, that you don't have to remove the whole thing, just bring it to a much smaller radius...that wide contact area is a killer for rendering.
Another option is to use a self adhesive slick strip under the felt. As you mention, the wire will grind through the felt quickly, if not immediately, and bear on the UMHW material. I've done this on plate configurations with crazy high termination angles, like 45 deg, which the could not be ground and corrected. It works pretty well.
Just make sure you have some friction there, because the UMHW and co-polymers can be a too low friction, if not configured well...which is a different kind of pain to tune. Keep the termination angle elevated, as in 20-25deg, or keep the contact surface wide (1" or more), or add some dense felt after the UMHW...some way to make sure there is some friction. Some of my co-polymer terminations are too low friction. Friction in the "just right" is such a pleasure to tune.
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Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
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Original Message:
Sent: 02-24-2020 09:37
From: Floyd Gadd
Subject: Cast Counterbearing Treatment
I have a 1925 Gerhard Heintzman with the cast-into-the-plate equivalent of half-round counterbearings with a radius in the range of about 3/8".
These are found in all sections of the scale. Original arrangement was cloth glued in place over top, and over time pretty much every string wore through the cloth. I'm looking for a way to reduce future friction problems as I get ready to restring.
The invasive solution would be to grind out the existing structures and replace them with acetal copolymer. I don't think I'm ready to try that, though I had a good experience using the copolymer on my last restring. Is there something lubricious that I could use under the cloth, or in place of the cloth, that might reduce friction issues a few years down the road?
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Floyd Gadd
Regina SK
306-502-9103
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