Official Luthiers Forum!

Owned and operated by Lance Kragenbrink
It is currently Thu Nov 21, 2024 10:08 pm


All times are UTC - 5 hours





Post new topic Reply to topic  [ 10 posts ] 
Author Message
PostPosted: Fri Aug 23, 2024 7:20 am 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Fri Jul 10, 2009 4:44 am
Posts: 5491
First name: colin
Last Name: north
Country: Scotland.
Focus: Build
Status: Semi-pro
I have a guitar in with a screwed on neck like an Eko/Epiphone (no heel)
It's 50 years old and owner's first guitar, so it's a bit sentimental, only worth maybe $600 max. and I've done a lot of work for him so I'd like to help.
The top has delaminated at the top of the neck block.
It only has a small area glued each side of the neck pocket, so there has been a lot of stress on a small area.
With string tension, the neck rises, the top bulges in the neck block area and the action is very high.
The delamination is uneven, not just one layer, up and down a bit though the top over the neck block's length.
Can I try working 24 hr epoxy into the delaminations, clamping it down 24hrs, and then epoxying a wooden fillet at each side of the neck block and top meeting point?
I know epoxy in normally a no-no, but it's only thing I can think of doing without an expensive re-topping?

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.


Last edited by Colin North on Sun Aug 25, 2024 6:45 am, edited 4 times in total.


These users thanked the author Colin North for the post: Kbore (Mon Aug 26, 2024 4:40 pm)
Top
 Profile  
 
PostPosted: Fri Aug 23, 2024 8:01 am 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Fri Aug 19, 2005 4:02 am
Posts: 3263
Location: The Woodlands, Texas
First name: Barry
Last Name: Daniels
Epoxy would be fine for a guitar like that. Most of those heel-less epis of that vintage have not survived because they were a terrible design and poorly constructed.


Top
 Profile  
 
PostPosted: Fri Aug 23, 2024 11:55 am 
Offline
Old Growth Brazilian Rosewood
Old Growth Brazilian Rosewood
User avatar

Joined: Fri Nov 02, 2007 9:49 am
Posts: 13385
Location: Ann Arbor, Michigan
First name: Hesh
Last Name: Breakstone
City: Ann Arbor
State: Michigan
Country: United States
Status: Professional
We've never attempted to relaminate a laminated top so I really can't say. We have had the conversation with many clients about guitars with sentimental value that they still can be kept, hung on a wall, whatever and that repairs don't have to be made. But I know you know that and I understand that this is a good client and you are a good guy for wanting to help Colin.

Thinking out loud here: What about clamping things up and positioning the box so that you can employ gravity and a quality this CA to wick into the laminates once they are clamped in place? Perhaps use that white cutting board material as cauls since CA won't stick to them. Could be a God awful mess too if too much CA is deployed.

Pics would be helpful too I am not sure I completely understand what this looks like.



These users thanked the author Hesh for the post: Kbore (Mon Aug 26, 2024 4:41 pm)
Top
 Profile  
 
PostPosted: Fri Aug 23, 2024 2:45 pm 
Offline
Cocobolo
Cocobolo

Joined: Wed Jan 22, 2014 4:59 pm
Posts: 362
Location: Co cork Ireland
Country: Ireland
Focus: Build
Least if you retopped it they'd end up with a good guitar?


Top
 Profile  
 
PostPosted: Sat Aug 24, 2024 1:24 am 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Fri Jul 10, 2009 4:44 am
Posts: 5491
First name: colin
Last Name: north
Country: Scotland.
Focus: Build
Status: Semi-pro
mike-p wrote:
Least if you re-topped it they'd end up with a good guitar?

I think the neck attachment system is the basic problem, string tension is held mainly by 2 lengthwise strips of wood ~3/16 wide (top of neck block) glued to a laminate top.
It may be that the glue joint on the bass side has failed first, putting as the stress on the treble side, where the glue has held but the laminations just couldn't take all that stress.
I'll try to get some pics today.
Not the best design to start with as Barry said.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.



These users thanked the author Colin North for the post: Kbore (Mon Aug 26, 2024 4:41 pm)
Top
 Profile  
 
PostPosted: Sat Aug 24, 2024 8:45 am 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Fri Jul 10, 2009 4:44 am
Posts: 5491
First name: colin
Last Name: north
Country: Scotland.
Focus: Build
Status: Semi-pro
I should wear my glasses all the time!
The top was not actually delaminated, just some wood had come away from the top of the neck block with the glue
Propped up the top with a stick between UTB and a back brace to open the gap a little, then with some PSA abrasive on a pallette knife cleaned up the area, top and neck block, work araldite ultra in there with the knife, clamp and check there's squeeze out both sides.
Job's a good'un probably, but just in case, I'll be epoxying in about 6.5 cms of triangular section mahogany between top and neck block sides butting up against the UTB to help take the string tension.ImageImageImageImageImage

Sent from my moto g(50) using Tapatalk

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.



These users thanked the author Colin North for the post (total 3): Kbore (Mon Aug 26, 2024 4:43 pm) • Hesh (Mon Aug 26, 2024 5:17 am) • SteveSmith (Sat Aug 24, 2024 12:02 pm)
Top
 Profile  
 
PostPosted: Sat Aug 24, 2024 2:58 pm 
Offline
Koa
Koa

Joined: Mon Feb 13, 2012 8:49 pm
Posts: 1039
First name: peter
Last Name: havriluk
City: granby
State: ct
Zip/Postal Code: 06035
Country: usa
Focus: Build
Status: Amateur
Pictures help. I don't see a delaminated top, I see a top that's broken free of the rim and neck block.

_________________
Peter Havriluk


Top
 Profile  
 
PostPosted: Sat Aug 24, 2024 3:00 pm 
Offline
Koa
Koa

Joined: Mon Feb 13, 2012 8:49 pm
Posts: 1039
First name: peter
Last Name: havriluk
City: granby
State: ct
Zip/Postal Code: 06035
Country: usa
Focus: Build
Status: Amateur
Pictures help. I don't see a delaminated top, I see a top that's broken free of the neck block.

_________________
Peter Havriluk


Top
 Profile  
 
PostPosted: Sun Aug 25, 2024 6:48 am 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Fri Jul 10, 2009 4:44 am
Posts: 5491
First name: colin
Last Name: north
Country: Scotland.
Focus: Build
Status: Semi-pro
phavriluk wrote:
Pictures help. I don't see a delaminated top, I see a top that's broken free of the neck block.


I did see that, when I had my glasses on - see my last post

phavriluk wrote:
Pictures help. I don't see a delaminated top, I see a top that's broken free of the neck block.


I did see that, when I had my glasses on - see my last post

:geek:
:geek: :roll:

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.



These users thanked the author Colin North for the post: Kbore (Mon Aug 26, 2024 4:44 pm)
Top
 Profile  
 
PostPosted: Mon Aug 26, 2024 5:23 am 
Offline
Old Growth Brazilian Rosewood
Old Growth Brazilian Rosewood
User avatar

Joined: Fri Nov 02, 2007 9:49 am
Posts: 13385
Location: Ann Arbor, Michigan
First name: Hesh
Last Name: Breakstone
City: Ann Arbor
State: Michigan
Country: United States
Status: Professional
Not what I thought either I thought that the top wood itself on a laminated top instrument was delaminating.

Looks like a great fix Colin, nice work.

Regarding retopping a guitar in the US for an established shop to retop an acoustic guitar if the customer was charged what it costs to do properly expect a $2 - 3K bill. It's a big job with finish matching and blending, reinstalling a neck and more. Most shops we know who are busy would not even take it on not because of complexity but because of opportunity costs. We have many, many gigging musicians who need fast turnaround so the show can go on and have to maintain some bandwidth for them at all times.

Of all the things we will do including neck resets and more retopping a guitar is a bigger job than anything else for a repair shop short of a full on restoration which at times is less involved than a retop too.



These users thanked the author Hesh for the post (total 2): Colin North (Tue Aug 27, 2024 7:53 am) • Kbore (Mon Aug 26, 2024 4:45 pm)
Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 4 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