Official Luthiers Forum!

Owned and operated by Lance Kragenbrink
It is currently Mon Nov 25, 2024 12:13 am


All times are UTC - 5 hours





Post new topic Reply to topic  [ 19 posts ] 
Author Message
PostPosted: Mon May 17, 2021 11:52 am 
Offline
Koa
Koa

Joined: Fri Feb 10, 2017 11:09 pm
Posts: 870
Location: Cowichan Valley, BC, Canada
First name: Conor
Last Name: Searl
City: Duncan
State: British Columbia
Zip/Postal Code: V9L 2E5
Country: Canada
Status: Semi-pro
Any creative solutions for re-gluing the bridge on this tiny guitar with very unconventional bracing and very small offset soundhole?


You do not have the required permissions to view the files attached to this post.


Top
 Profile  
 
PostPosted: Mon May 17, 2021 2:51 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Sun Mar 06, 2011 12:04 am
Posts: 5821
First name: Chris
Last Name: Pile
City: Wichita
State: Kansas
Country: Good old US of A
Focus: Repair
Status: Professional
A stack of books? Not kidding - did it that way once or twice when nothing else would work.

_________________
"Act your age, not your shoe size" - Prince



These users thanked the author Chris Pile for the post: Conor_Searl (Mon May 17, 2021 3:36 pm)
Top
 Profile  
 
PostPosted: Mon May 17, 2021 3:51 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Tue May 13, 2008 10:44 am
Posts: 6256
Location: Virginia
Re-top it?

:D

If you have a tremendous amount of patience and some special curved and long forceps you might be able to wedge some 'go bars' under the bridge patch and clamp it from the outside. Perhaps using magnets to align them.



These users thanked the author jfmckenna for the post: Conor_Searl (Wed May 19, 2021 3:21 pm)
Top
 Profile  
 
PostPosted: Mon May 17, 2021 4:20 pm 
Offline
Koa
Koa
User avatar

Joined: Wed Jan 14, 2009 3:14 am
Posts: 992
Location: Shefford, Québec
First name: Tim
Last Name: Mullin
City: Shefford
State: QC
Zip/Postal Code: J2M 1R5
Country: Canada
Focus: Build
Status: Professional
Make sure the fit is perfect (as always) and use HHG. Hi clamping pressure not necessary. At least it has bridge pins to help keep it aligned.


Sent from my iPhone using Tapatalk



These users thanked the author Tim Mullin for the post: Conor_Searl (Wed May 19, 2021 3:21 pm)
Top
 Profile  
 
PostPosted: Mon May 17, 2021 10:21 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Sat May 17, 2008 1:11 pm
Posts: 2373
Location: Spokane, Washington
First name: Pat
Last Name: Foster
Country: USA
Focus: Build
Like Tim says, perfect fit and HHG. Then a vacuum clamp.

_________________
formerly known around here as burbank
_________________

http://www.patfosterguitars.com



These users thanked the author Pat Foster for the post: Conor_Searl (Wed May 19, 2021 3:21 pm)
Top
 Profile  
 
PostPosted: Tue May 18, 2021 3:38 am 
Offline
Cocobolo
Cocobolo

Joined: Thu Feb 09, 2012 4:10 pm
Posts: 279
First name: Chris
Last Name: Reed
City: Stowmarket
State: Suffolk
Zip/Postal Code: IP14 2EX
Country: UK
Focus: Build
Status: Amateur
Rare earth magnets are really handy for something like this.

I'd use HHG and hold the bridge in place with hand pressure until the glue grips it.

Then apply the rare earth magnets outside, taped to some card taped to the bridge, then magnets inside applied on the end of a bent stick.

Finally heat the bridge to reactivate the glue, then leave overnight before removing the magnets.



These users thanked the author profchris for the post: Conor_Searl (Wed May 19, 2021 3:21 pm)
Top
 Profile  
 
PostPosted: Tue May 18, 2021 11:31 am 
Offline
Koa
Koa

Joined: Fri Feb 10, 2017 11:09 pm
Posts: 870
Location: Cowichan Valley, BC, Canada
First name: Conor
Last Name: Searl
City: Duncan
State: British Columbia
Zip/Postal Code: V9L 2E5
Country: Canada
Status: Semi-pro
Tim Mullin wrote:
Make sure the fit is perfect (as always) and use HHG. Hi clamping pressure not necessary. At least it has bridge pins to help keep it aligned.


Sent from my iPhone using Tapatalk


Is hi clamping pressure unnecessary because of the use of HHG, or simply not necessary for regluing a bridge?


Top
 Profile  
 
PostPosted: Tue May 18, 2021 11:32 am 
Offline
Koa
Koa

Joined: Fri Feb 10, 2017 11:09 pm
Posts: 870
Location: Cowichan Valley, BC, Canada
First name: Conor
Last Name: Searl
City: Duncan
State: British Columbia
Zip/Postal Code: V9L 2E5
Country: Canada
Status: Semi-pro
profchris wrote:
Rare earth magnets are really handy for something like this.

I'd use HHG and hold the bridge in place with hand pressure until the glue grips it.

Then apply the rare earth magnets outside, taped to some card taped to the bridge, then magnets inside applied on the end of a bent stick.

Finally heat the bridge to reactivate the glue, then leave overnight before removing the magnets.


Do you think this method could work using original tite-bond? I've never used HHG. The extra open time of tite-bond could mean not having to re-heat the bridge once magnets are in place.


Top
 Profile  
 
PostPosted: Tue May 18, 2021 11:43 am 
Offline
Koa
Koa

Joined: Fri Feb 10, 2017 11:09 pm
Posts: 870
Location: Cowichan Valley, BC, Canada
First name: Conor
Last Name: Searl
City: Duncan
State: British Columbia
Zip/Postal Code: V9L 2E5
Country: Canada
Status: Semi-pro
Pat Foster wrote:
Like Tim says, perfect fit and HHG. Then a vacuum clamp.


Vacuum clamps are slick! I'd never looked at them too closely. That might be the perfect trick.


Top
 Profile  
 
PostPosted: Wed May 19, 2021 1:50 pm 
Offline
Koa
Koa

Joined: Wed Feb 17, 2016 8:54 am
Posts: 854
State: Texas
Country: United States
Focus: Repair
You have some good advice here. I've done these before, they're interesting.

Make sure the fit is perfect (100% perfect no exceptions) and use HHG or Old Brown Glue. I made a little micro go bar deck that only reached over the bridge area (like a 1x3) and would screw to the bench. That way it was super easy to get equal pressure on all parts of the bridge and to get it aligned correctly. If you want I can draw it out for you but you're pretty smart and could probably figure it out.



These users thanked the author DanKirkland for the post: Conor_Searl (Wed May 19, 2021 3:21 pm)
Top
 Profile  
 
PostPosted: Wed May 19, 2021 3:22 pm 
Offline
Koa
Koa

Joined: Fri Feb 10, 2017 11:09 pm
Posts: 870
Location: Cowichan Valley, BC, Canada
First name: Conor
Last Name: Searl
City: Duncan
State: British Columbia
Zip/Postal Code: V9L 2E5
Country: Canada
Status: Semi-pro
DanKirkland wrote:
You have some good advice here. I've done these before, they're interesting.

Make sure the fit is perfect (100% perfect no exceptions) and use HHG or Old Brown Glue. I made a little micro go bar deck that only reached over the bridge area (like a 1x3) and would screw to the bench. That way it was super easy to get equal pressure on all parts of the bridge and to get it aligned correctly. If you want I can draw it out for you but you're pretty smart and could probably figure it out.


So the go bars are exerting pressure from the outside, but there's nothing inside?


Top
 Profile  
 
PostPosted: Wed May 19, 2021 3:33 pm 
Offline
Koa
Koa

Joined: Wed Feb 17, 2016 8:54 am
Posts: 854
State: Texas
Country: United States
Focus: Repair
Conor_Searl wrote:
DanKirkland wrote:
You have some good advice here. I've done these before, they're interesting.

Make sure the fit is perfect (100% perfect no exceptions) and use HHG or Old Brown Glue. I made a little micro go bar deck that only reached over the bridge area (like a 1x3) and would screw to the bench. That way it was super easy to get equal pressure on all parts of the bridge and to get it aligned correctly. If you want I can draw it out for you but you're pretty smart and could probably figure it out.


So the go bars are exerting pressure from the outside, but there's nothing inside?


Not quite. You want maybe 14-16" of space between the beam and the bridge. I used small cutoffs from tops as the pressure bars. You can drill little spots into the bar to give them something to hold onto while you place them. This way you have access to the bridge during the glue up. Sorry I wasn't more clear previously.


Top
 Profile  
 
PostPosted: Wed May 19, 2021 3:38 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Tue May 13, 2008 10:44 am
Posts: 6256
Location: Virginia
I think what conor is saying is that with that gobar set up there is no opposing force from the inside. That's why I was suggesting putting gobars on the inside so that when you clamp you have something to take the pressure. I'm sure it would work though. You just have to be careful applying pressure to the bridge that is not supported on the inside. I have done this before and it works. You don't get ideal clamping pressure but as mentioned a good fit with HHG is probably good enough, that with a bit of pressure even better.

It would be a PIA to get gobars inside that thing but violin makers do something similar with the sound post.



These users thanked the author jfmckenna for the post: Conor_Searl (Wed May 19, 2021 4:30 pm)
Top
 Profile  
 
PostPosted: Wed May 19, 2021 4:21 pm 
Offline
Contributing Member
Contributing Member

Joined: Fri Jan 11, 2013 2:26 pm
Posts: 487
First name: Carl
Last Name: Dickinson
City: Forest Ranch
State: California
Zip/Postal Code: 95942
Country: USA
Focus: Build
Status: Amateur
How about inflating a balloon inside to provide the opposing pressure to the gobars or to the Pile of books?



These users thanked the author CarlD for the post: Conor_Searl (Wed May 19, 2021 4:31 pm)
Top
 Profile  
 
PostPosted: Wed May 19, 2021 4:31 pm 
Offline
Koa
Koa

Joined: Fri Feb 10, 2017 11:09 pm
Posts: 870
Location: Cowichan Valley, BC, Canada
First name: Conor
Last Name: Searl
City: Duncan
State: British Columbia
Zip/Postal Code: V9L 2E5
Country: Canada
Status: Semi-pro
jfmckenna wrote:
It would be a PIA to get gobars inside that thing but violin makers do something similar with the sound post.


This is why violin makers are the real luthiers right? beehive



These users thanked the author Conor_Searl for the post: jfmckenna (Thu May 20, 2021 9:49 am)
Top
 Profile  
 
PostPosted: Wed May 19, 2021 7:24 pm 
Offline
Koa
Koa

Joined: Mon Feb 13, 2012 8:49 pm
Posts: 1041
First name: peter
Last Name: havriluk
City: granby
State: ct
Zip/Postal Code: 06035
Country: usa
Focus: Build
Status: Amateur
Nobody HAS to do any job. If OP is not experienced in this job on this sort of guitar, I think he can encourage the owner to look elsewhere without feeling bad about it. This repair is sounding like a time-and-materials job and the owner's gonna faint when he sees the bill. Or OP will have given his time away on an unprofitable job.

_________________
Peter Havriluk


Top
 Profile  
 
PostPosted: Thu May 20, 2021 11:35 am 
Offline
Koa
Koa
User avatar

Joined: Wed Jan 14, 2009 3:14 am
Posts: 992
Location: Shefford, Québec
First name: Tim
Last Name: Mullin
City: Shefford
State: QC
Zip/Postal Code: J2M 1R5
Country: Canada
Focus: Build
Status: Professional
No need to complicate this. As stated by experienced repair folks here, HHG is recommended because (1) it’s by far the easiest glue to clean up and (2) it will literally pull a well-fitted joint together. Some classical builders would argue “no clamping required”, i.e., a “rub joint”. Some VERY LIGHT pressure can be organized in a go bar deck, without any distortion of top or bridge. No interior bars, magnets, or cauls. And once you use HHG for a bridge, you’ll never go back.


Sent from my iPhone using Tapatalk



These users thanked the author Tim Mullin for the post: Conor_Searl (Thu May 20, 2021 12:17 pm)
Top
 Profile  
 
PostPosted: Thu Feb 03, 2022 4:38 pm 
Offline
Mahogany
Mahogany

Joined: Thu Oct 21, 2021 4:23 pm
Posts: 43
First name: Yeaux
Last Name: Maumma
Focus: Repair
Status: Professional
2 to 3 large cam clamps from stewmac. be careful not to overtighten and pop a brace as these are some sort of fan brace or v brace if memory serves?


Top
 Profile  
 
PostPosted: Fri Feb 04, 2022 7:24 am 
Offline
Old Growth Brazilian Rosewood
Old Growth Brazilian Rosewood
User avatar

Joined: Fri Nov 02, 2007 9:49 am
Posts: 13386
Location: Ann Arbor, Michigan
First name: Hesh
Last Name: Breakstone
City: Ann Arbor
State: Michigan
Country: United States
Status: Professional
This is a very fine example of a guitar that zero thought was given to serviceability. Tacomas are not a welcome sight in our shop for this reason and others such as their acoustic bass is under braced and they don't hold up well.

Long reach clamps are an option but they also flex a lot because of the length so really snugging them down is problematic. Books as Chris said is an option too only it obscures squeeze-out clean up somewhat but no biggie.

What ever method you arrive it Connor none of them are idea and I would not trust the repair over time and we already know that the client likely didn't humidify the thing so this could happen again. I would expand the gluing surface too to within .005" of the actual perimeter foot print to keep the repair invisible but to improve the changes that this time this bridge and this guitar get along better. I also would not guarantee the repair like we usually do, this instrument is not servicable, was never engineered to have the most common repairs like a bridge reglue done to it. We can't change that.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 19 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group
phpBB customization services by 2by2host.com