Pianotech

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 

Dave Conte,

I have pulled numerous separating rims back together. If your widest gap is (only) 1/16" you can probably pull in back together with beefy bar clamps, spaced tightly around the perimeter of the rim. See attached photo. I had great success with cold hide glue for this procedure. Work a ton of it down into the fissure. Drill injection holes into the inner rim to hydraulically pump the glue in if you have to, filling them with plugs or screws later. Indeed, if I felt more fortification was required, I ran #20 wood screws through the inner rim into the outer rim all the way around. A right-angle drill was used to create all the necessary through and threading holes. In any event, leave it clamped up for two days before even thinking about un-clamping. Best of luck, my fine friend.

David G. Hughes, RPT

Baltimore Chapter 

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 

David, it seems that you are reporting on cases in which the originally glued together laminate layers have come apart.

I'm not sure this is the best approach in a piano in which two separately created inner and outer cases have been put together late in the manufacturing process. I don't think it matters that much if there are gaps between the inner and outer cases. Trying to force together two furniture parts that perhaps never fit together in the first place may not be necessary or helpful.

You've had a lot of experience restoring historic instruments. I've had a lot of experience servicing DampChasers under late 20th century Asian-built instruments!

Dave Conte,

I have pulled numerous separating rims back together. If your widest gap is (only) 1/16" you can probably pull in back together with beefy bar clamps, spaced tightly around the perimeter of the rim. See attached photo. I had great success with cold hide glue for this procedure. Work a ton of it down into the fissure. Drill injection holes into the inner rim to hydraulically pump the glue in if you have to, filling them with plugs or screws later. Indeed, if I felt more fortification was required, I ran #20 wood screws through the inner rim into the outer rim all the way around. A right-angle drill was used to create all the necessary through and threading holes. In any event, leave it clamped up for two days before even thinking about un-clamping. Best of luck, my fine friend.

David G. Hughes, RPT

Baltimore Chapter 

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 

Ed Sutton,

I have used this technique on Steinways as well as Asian two-separate-rim pianos. I have performed it on Mason & Hamlin pianos as well, another two-separate-rim, American piano. The results are the same.

I go back and look at these pianos years later. There is no separation.

David G. Hughes, RPT

Baltimore Chapter

David, it seems that you are reporting on cases in which the originally glued together laminate layers have come apart.

I'm not sure this is the best approach in a piano in which two separately created inner and outer cases have been put together late in the manufacturing process. I don't think it matters that much if there are gaps between the inner and outer cases. Trying to force together two furniture parts that perhaps never fit together in the first place may not be necessary or helpful.

You've had a lot of experience restoring historic instruments. I've had a lot of experience servicing DampChasers under late 20th century Asian-built instruments!

Dave Conte,

I have pulled numerous separating rims back together. If your widest gap is (only) 1/16" you can probably pull in back together with beefy bar clamps, spaced tightly around the perimeter of the rim. See attached photo. I had great success with cold hide glue for this procedure. Work a ton of it down into the fissure. Drill injection holes into the inner rim to hydraulically pump the glue in if you have to, filling them with plugs or screws later. Indeed, if I felt more fortification was required, I ran #20 wood screws through the inner rim into the outer rim all the way around. A right-angle drill was used to create all the necessary through and threading holes. In any event, leave it clamped up for two days before even thinking about un-clamping. Best of luck, my fine friend.

David G. Hughes, RPT

Baltimore Chapter 

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 

Ed Sutton,

I have used this technique on Steinways as well as Asian two-separate-rim pianos. I have performed it on Mason & Hamlin pianos as well, another two-separate-rim, American piano. The results are the same.

I go back and look at these pianos years later. There is no separation.

David G. Hughes, RPT

Baltimore Chapter

David, it seems that you are reporting on cases in which the originally glued together laminate layers have come apart.

I'm not sure this is the best approach in a piano in which two separately created inner and outer cases have been put together late in the manufacturing process. I don't think it matters that much if there are gaps between the inner and outer cases. Trying to force together two furniture parts that perhaps never fit together in the first place may not be necessary or helpful.

You've had a lot of experience restoring historic instruments. I've had a lot of experience servicing DampChasers under late 20th century Asian-built instruments!

Dave Conte,

I have pulled numerous separating rims back together. If your widest gap is (only) 1/16" you can probably pull in back together with beefy bar clamps, spaced tightly around the perimeter of the rim. See attached photo. I had great success with cold hide glue for this procedure. Work a ton of it down into the fissure. Drill injection holes into the inner rim to hydraulically pump the glue in if you have to, filling them with plugs or screws later. Indeed, if I felt more fortification was required, I ran #20 wood screws through the inner rim into the outer rim all the way around. A right-angle drill was used to create all the necessary through and threading holes. In any event, leave it clamped up for two days before even thinking about un-clamping. Best of luck, my fine friend.

David G. Hughes, RPT

Baltimore Chapter 

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 

Wim:

Liked your article in Nov journal on expanding brackets. You will find that a center line guage attached to your caliper to be a handy tool

for measuring action spread. Available from Spi and others.

Ed Sutton,

I have used this technique on Steinways as well as Asian two-separate-rim pianos. I have performed it on Mason & Hamlin pianos as well, another two-separate-rim, American piano. The results are the same.

I go back and look at these pianos years later. There is no separation.

David G. Hughes, RPT

Baltimore Chapter

David, it seems that you are reporting on cases in which the originally glued together laminate layers have come apart.

I'm not sure this is the best approach in a piano in which two separately created inner and outer cases have been put together late in the manufacturing process. I don't think it matters that much if there are gaps between the inner and outer cases. Trying to force together two furniture parts that perhaps never fit together in the first place may not be necessary or helpful.

You've had a lot of experience restoring historic instruments. I've had a lot of experience servicing DampChasers under late 20th century Asian-built instruments!

Dave Conte,

I have pulled numerous separating rims back together. If your widest gap is (only) 1/16" you can probably pull in back together with beefy bar clamps, spaced tightly around the perimeter of the rim. See attached photo. I had great success with cold hide glue for this procedure. Work a ton of it down into the fissure. Drill injection holes into the inner rim to hydraulically pump the glue in if you have to, filling them with plugs or screws later. Indeed, if I felt more fortification was required, I ran #20 wood screws through the inner rim into the outer rim all the way around. A right-angle drill was used to create all the necessary through and threading holes. In any event, leave it clamped up for two days before even thinking about un-clamping. Best of luck, my fine friend.

David G. Hughes, RPT

Baltimore Chapter 

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 

Parker,

Can you give more info on that? Can't find anything.

Peter Grey Piano Doctor 

Wim:

Liked your article in Nov journal on expanding brackets. You will find that a center line guage attached to your caliper to be a handy tool

for measuring action spread. Available from Spi and others.

Ed Sutton,

I have used this technique on Steinways as well as Asian two-separate-rim pianos. I have performed it on Mason & Hamlin pianos as well, another two-separate-rim, American piano. The results are the same.

I go back and look at these pianos years later. There is no separation.

David G. Hughes, RPT

Baltimore Chapter

David, it seems that you are reporting on cases in which the originally glued together laminate layers have come apart.

I'm not sure this is the best approach in a piano in which two separately created inner and outer cases have been put together late in the manufacturing process. I don't think it matters that much if there are gaps between the inner and outer cases. Trying to force together two furniture parts that perhaps never fit together in the first place may not be necessary or helpful.

You've had a lot of experience restoring historic instruments. I've had a lot of experience servicing DampChasers under late 20th century Asian-built instruments!

Dave Conte,

I have pulled numerous separating rims back together. If your widest gap is (only) 1/16" you can probably pull in back together with beefy bar clamps, spaced tightly around the perimeter of the rim. See attached photo. I had great success with cold hide glue for this procedure. Work a ton of it down into the fissure. Drill injection holes into the inner rim to hydraulically pump the glue in if you have to, filling them with plugs or screws later. Indeed, if I felt more fortification was required, I ran #20 wood screws through the inner rim into the outer rim all the way around. A right-angle drill was used to create all the necessary through and threading holes. In any event, leave it clamped up for two days before even thinking about un-clamping. Best of luck, my fine friend.

David G. Hughes, RPT

Baltimore Chapter 

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 

go to mscindustrial or mcmaster carr. look up center line guage. Spi makes a large number of add ons to calipers that enhance functionality.

Parker,

Can you give more info on that? Can't find anything.

Peter Grey Piano Doctor 

Wim:

Liked your article in Nov journal on expanding brackets. You will find that a center line guage attached to your caliper to be a handy tool

for measuring action spread. Available from Spi and others.

Ed Sutton,

I have used this technique on Steinways as well as Asian two-separate-rim pianos. I have performed it on Mason & Hamlin pianos as well, another two-separate-rim, American piano. The results are the same.

I go back and look at these pianos years later. There is no separation.

David G. Hughes, RPT

Baltimore Chapter

David, it seems that you are reporting on cases in which the originally glued together laminate layers have come apart.

I'm not sure this is the best approach in a piano in which two separately created inner and outer cases have been put together late in the manufacturing process. I don't think it matters that much if there are gaps between the inner and outer cases. Trying to force together two furniture parts that perhaps never fit together in the first place may not be necessary or helpful.

You've had a lot of experience restoring historic instruments. I've had a lot of experience servicing DampChasers under late 20th century Asian-built instruments!

Dave Conte,

I have pulled numerous separating rims back together. If your widest gap is (only) 1/16" you can probably pull in back together with beefy bar clamps, spaced tightly around the perimeter of the rim. See attached photo. I had great success with cold hide glue for this procedure. Work a ton of it down into the fissure. Drill injection holes into the inner rim to hydraulically pump the glue in if you have to, filling them with plugs or screws later. Indeed, if I felt more fortification was required, I ran #20 wood screws through the inner rim into the outer rim all the way around. A right-angle drill was used to create all the necessary through and threading holes. In any event, leave it clamped up for two days before even thinking about un-clamping. Best of luck, my fine friend.

David G. Hughes, RPT

Baltimore Chapter 

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 

Peter and Parker. 

Please move this discussion to another thread and please don't hijack the conversation. 

Thanks!

go to mscindustrial or mcmaster carr. look up center line guage. Spi makes a large number of add ons to calipers that enhance functionality.

Parker,

Can you give more info on that? Can't find anything.

Peter Grey Piano Doctor 

Wim:

Liked your article in Nov journal on expanding brackets. You will find that a center line guage attached to your caliper to be a handy tool

for measuring action spread. Available from Spi and others.

Ed Sutton,

I have used this technique on Steinways as well as Asian two-separate-rim pianos. I have performed it on Mason & Hamlin pianos as well, another two-separate-rim, American piano. The results are the same.

I go back and look at these pianos years later. There is no separation.

David G. Hughes, RPT

Baltimore Chapter

David, it seems that you are reporting on cases in which the originally glued together laminate layers have come apart.

I'm not sure this is the best approach in a piano in which two separately created inner and outer cases have been put together late in the manufacturing process. I don't think it matters that much if there are gaps between the inner and outer cases. Trying to force together two furniture parts that perhaps never fit together in the first place may not be necessary or helpful.

You've had a lot of experience restoring historic instruments. I've had a lot of experience servicing DampChasers under late 20th century Asian-built instruments!

Dave Conte,

I have pulled numerous separating rims back together. If your widest gap is (only) 1/16" you can probably pull in back together with beefy bar clamps, spaced tightly around the perimeter of the rim. See attached photo. I had great success with cold hide glue for this procedure. Work a ton of it down into the fissure. Drill injection holes into the inner rim to hydraulically pump the glue in if you have to, filling them with plugs or screws later. Indeed, if I felt more fortification was required, I ran #20 wood screws through the inner rim into the outer rim all the way around. A right-angle drill was used to create all the necessary through and threading holes. In any event, leave it clamped up for two days before even thinking about un-clamping. Best of luck, my fine friend.

David G. Hughes, RPT

Baltimore Chapter 

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 

Dave, I'm trying to picture this. It's separating in multiple places or just one? I've never encountered this but I'm thinking when I have seen separating in vertical pin blocks from backs, the back stays straight and the pin block side has a visible curve usually. I've also run into verticals where one side of the cabinet detaches completely from the back; in that case it turned out to be that the cabinet wood was so smooth and clamped so tightly in manufacture that it forced all the glue out of the joint. 

Get pictures when you can. David's suggestion of reinforcing with screws would stabilize it whether you fill or clamp. It sounds like the piano was a mess, so probably you couldn't tell if the condition was creating any adverse effects on tuning stability etc.

------------------------------
Steven Rosenthal RPT
Honolulu HI
(808) 521-7129

Original Message:
Sent: 11-01-2025 18:40
From: Dave Conte
Subject: Boston grand rim separating

Peter and Parker. 

Please move this discussion to another thread and please don't hijack the conversation. 

Thanks!

------------------------------
Dave Conte, RPT

Piano Technician in Residence
The University of Tennessee
College of Music
Knoxville TN
(817) 307-5656
Owner: Rocky Top Piano

Original Message:
Sent: 11-01-2025 16:52
From: Parker Leigh
Subject: Boston grand rim separating

go to mscindustrial or mcmaster carr. look up center line guage. Spi makes a large number of add ons to calipers that enhance functionality.

------------------------------
Parker Leigh RPT
Winchester VA
(540) 722-3865

Original Message:
Sent: 11-01-2025 15:02
From: Peter Grey
Subject: Boston grand rim separating

Parker,

Can you give more info on that? Can't find anything.

Peter Grey Piano Doctor 

------------------------------
Peter Grey
Stratham NH
(603) 686-2395
pianodoctor57@gmail.com

Original Message:
Sent: 11-01-2025 13:49
From: Parker Leigh
Subject: Boston grand rim separating

Wim:

Liked your article in Nov journal on expanding brackets. You will find that a center line guage attached to your caliper to be a handy tool

for measuring action spread. Available from Spi and others.

------------------------------
Parker Leigh RPT
Winchester VA
(540) 722-3865

Original Message:
Sent: 09-04-2025 09:39
From: Wim Blees
Subject: Boston grand rim separating

Original Message:
Sent: 9/4/2025 9:25:00 AM
From: David Hughes
Subject: RE: Boston grand rim separating

Ed Sutton,

I have used this technique on Steinways as well as Asian two-separate-rim pianos. I have performed it on Mason & Hamlin pianos as well, another two-separate-rim, American piano. The results are the same.

I go back and look at these pianos years later. There is no separation.

David G. Hughes, RPT

Baltimore Chapter

------------------------------
David Hughes RPT
Vintage Case Parts
Glyndon MD
(443) 522-2201

Original Message:
Sent: 09-04-2025 09:08
From: Ed Sutton
Subject: Boston grand rim separating

David, it seems that you are reporting on cases in which the originally glued together laminate layers have come apart.

I'm not sure this is the best approach in a piano in which two separately created inner and outer cases have been put together late in the manufacturing process. I don't think it matters that much if there are gaps between the inner and outer cases. Trying to force together two furniture parts that perhaps never fit together in the first place may not be necessary or helpful.

You've had a lot of experience restoring historic instruments. I've had a lot of experience servicing DampChasers under late 20th century Asian-built instruments!

------------------------------
Ed Sutton
ed440@me.com
(980) 254-7413

Original Message:
Sent: 09-04-2025 07:54
From: David Hughes
Subject: Boston grand rim separating

Dave Conte,

I have pulled numerous separating rims back together. If your widest gap is (only) 1/16" you can probably pull in back together with beefy bar clamps, spaced tightly around the perimeter of the rim. See attached photo. I had great success with cold hide glue for this procedure. Work a ton of it down into the fissure. Drill injection holes into the inner rim to hydraulically pump the glue in if you have to, filling them with plugs or screws later. Indeed, if I felt more fortification was required, I ran #20 wood screws through the inner rim into the outer rim all the way around. A right-angle drill was used to create all the necessary through and threading holes. In any event, leave it clamped up for two days before even thinking about un-clamping. Best of luck, my fine friend.

David G. Hughes, RPT

Baltimore Chapter 

------------------------------
David Hughes RPT
Vintage Case Parts
Glyndon MD
(443) 522-2201

Original Message:
Sent: 09-03-2025 13:40
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 

------------------------------
Dave Conte, RPT

Piano Technician in Residence
The University of Tennessee
College of Music
Knoxville TN
(817) 307-5656
Owner: Rocky Top Piano
------------------------------