My take is that for grands with separate inner and outer rims, the outer rims is essentially just "furniture," for looks, while the inner rim is designed to hold the soundboard, plate and strings.
From watching how grands were made in the Sauter factory, I saw that in production the inner rim is strung, chip tuned, then the action is fit to it and most of the work is done.
Only after this is an outer rim glued to it. This is, of course, in contrast to the Steinway method where the outer and inner rims are glued together all at the same time.
So I would look at filling the gap between the two as being more cosmetic than structural.
Regards,
Fred Sturm
http://fredsturm.net
www.artoftuning.com
"One's real life is so often the life that one does not lead" (Oscar Wilde)
Original Message:
Sent: 9/3/2025 1:40:00 PM
From: Dave Conte
Subject: Boston grand rim separating
I'm working on a 22 year old Boston GP-193 grand. I am told it was in an older (now demolished) building with steam heat for about a decade before I started. The inner and outer rims are separating, up to 1/16" gap in places. The veneer has lifted from the front corner where it's flat on the treble side to where the bent side begins (included just for information). I am going to recap the bridges and restring, so the piano can be flipped over without the plate. Attempting to clamp the rim completely closed will probably not do much good. The plan is to fill the voids with epoxy and just as much clamping pressure as it will accept. I typically will use System Three Clear Coat for this as it has a high tensile, flexural modulus and low elongation properties when cured, and because it is low viscosity to flow into the voids. Looking for feedback from anyone who has already done something similar. TIA
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Dave Conte, RPT
Piano Technician in Residence
The University of Tennessee
College of Music
Knoxville TN
(817) 307-5656
Owner: Rocky Top Piano
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