Official Luthiers Forum!

Solely owned and operated by Lance Kragenbrink
It is currently Wed Sep 30, 2020 11:57 pm


All times are UTC - 5 hours





Post new topic Reply to topic  [ 20 posts ] 
Author Message
PostPosted: Fri Jun 08, 2018 9:14 am 
Offline
Koa
Koa

Joined: Wed Feb 17, 2016 8:54 am
Posts: 665
State: Texas
Country: United States
Focus: Repair
Title says it all. This will be a little photo journal of getting this thing back together. Just for the sake of documenting it. This will be a fun one.

I had previous asked for advice on getting a stubborn bridge plate off of this guy. Previous "repair" had glued it in with hardcore waterroof titebond (thanks to Mr. Howard for helping make that diagnosis). Top was curved something fierce behind the bridge. Replacement plate was too short and did nothing to keep the top flat. The guitar initially came into my shop for a bridge reset. Upon asking the owner it had been reset about 7 times in a very short span.

I was also concerned because I noticed a gap when I removed the bridge initially. This should not be here.
Image

I had to remove the back to get at the plate, heating this thing and trying to remove via bent chisel was going nowhere. I decided to very carefully cut out the replacement plate.

Cupped and also not even glued in some areas. The plate extended to the exact edge of the bridge creating a massive bubble right at that tension point in the top. Plus the grain was running perfectly horizontal to the top, that might be "Vintage internet research correct" but that does not mean that it will work This grain just had no strength to resist the pull of the strings.
Image

Image

Here we uncover the horror that this warped monstrosity was hiding.

Image

Image

The pieces that came off all had the telltale signs of non-adherence of the glue. Surfaces were just gobbed up with the junk. Turns out that there multiple holes through the top that the bridge plate was supposed to "fill". It didn't work.
Image

Image

Digging a little further. What do I find but a badly glued scarf fill for the larger portion of the top under the bridge?

Image

This entire fill just fell apart as I removed the plate. You can see the scarf line. Again there seemed to be no ahesion of the glue.
Image

Image

And the top. Thank you previous repair guy. You nearly destroyed a very desirable guitar because of your idiocy.
Image

So the plan for the repair is simple. Thankfully it will be MUCH easier since the back is off already.

Scarf in new spruce for the top. Extend the scarf joint to go below both sides of the bridge.
Fill the gaps in the cross braces to allow better contact with the top.
Glue any loose braces
Patch any and all cracks.
New bridge plate with different grain orientation (diagonal to the top) and extended past the edge of the bridge to help flatten the top.
Put back back on, rebind, touchup finish
re-install bridge, restring clean and done

I was just in a similar situation not too long ago with a 1930s L-0 that had almost the exact same issue. Looking forward to having this one all back together again. It'll a long process, this is the owners main writing/recording guitar. I'm sad to see that it is such a sad state. Honestly if the previous repair guys had just not tried to hide the issues this would not have happened. I tried contacting the previous guy that had this in his shop but have received no response. Oh well, onwards and upwards.

I'll update this as I move along


Top
 Profile  
 
PostPosted: Fri Jun 08, 2018 10:16 am 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Sun Mar 06, 2011 12:04 am
Posts: 4410
First name: Chris
Last Name: Pile
City: Wichita
State: Kansas
Country: Good old US of A
Focus: Repair
Status: Professional
Wow. Just wow.

Power to you in your efforts, sir.

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


Top
 Profile  
 
PostPosted: Fri Jun 08, 2018 1:58 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Wed Oct 08, 2008 11:36 am
Posts: 5980
Location: Southeast US
City: Lenoir City
State: TN
Zip/Postal Code: 37772
Country: US
Focus: Repair
What Chris said.

Thanks for taking the time to post the photos, this one is interesting for sure!

_________________
Steve Smith
"Music is what feelings sound like"


Top
 Profile  
 
PostPosted: Fri Jun 08, 2018 11:50 pm 
Offline
Mahogany
Mahogany
User avatar

Joined: Fri Jun 08, 2018 2:36 pm
Posts: 66
First name: Oris
Last Name: Morton
City: Franklinton
State: North Carolina
Country: USA
Focus: Build
Status: Amateur
Please post photos through out the repair


Sent from my iPhone using Tapatalk


Top
 Profile  
 
PostPosted: Sat Jun 09, 2018 9:22 pm 
Offline
Cocobolo
Cocobolo

Joined: Thu Feb 15, 2018 11:06 am
Posts: 106
First name: Roy L
Last Name: Smith
City: Apache Junction
State: Az
Zip/Postal Code: 85119
Country: USA
Focus: Repair
Status: Amateur
Wow again....thanks for sharing this. it's gonna be epic.


Top
 Profile  
 
PostPosted: Thu Jun 21, 2018 12:23 pm 
Offline
Koa
Koa

Joined: Wed Feb 17, 2016 8:54 am
Posts: 665
State: Texas
Country: United States
Focus: Repair
Been working on this lately. I'll post more pictures later.

The scarf joint for the top patch has been completed.

The patch when in well with a huge amount of glue surface. However I realized that the end portion of the patch is almost directly in line with the edge of the bridge plate.

Image

Image

My thought is that 20 years down the road from now when the bridge plate wears out again and has to be replaced. That the guy removing the plate might possibly dig into the scarfed patch for the top.

So to counter this and prevent anything catastrophic from happening I am going to overlay the scarfed patch with a paper thin piece of spruce. It'll extend well past the edge of the bridge plate. It should also help to flatten the top quite a bit and reduce the extreme belly. I'll post detailed pics when I have time.


Top
 Profile  
 
PostPosted: Fri Jun 22, 2018 9:24 am 
Offline
Koa
Koa

Joined: Wed Feb 17, 2016 8:54 am
Posts: 665
State: Texas
Country: United States
Focus: Repair
Going back in a time with some of these. Progress is being made.

Cutting the scarfs for the top patch. I decided to extend the edge of the scarf much farther back. The previous repair guy had only had about 1/2" of wood for his scarf on the front side. For this repair we've got nearly a full inch on both sides of the missing top. I like these little violin planes for jobs like these. But these Ibex planes clog alot unless you put a little work into them. C'est la vie.

Image

Image

Patch is cut, fit to the scarfs, and glued in place.

Image

Image

Onto making the overlay. The overlay will be as thin as I can make it, I'm using light along with a micrometer to gauge the thickness. Basically I'm going for veneer thickness. This will also give alot of good clean gluing surface for the bridge plate to attach. Thus strengthening the top and helping to reduce the horrible bubble.

Image

Cut to size, It will be thinned down even further once it's glued in place. The spruce is flexible enough that it molds to the top and gives alot of reinforcement. Should last for a long while.

Image

Gluing it in place. I used my bridge plate caul to help clamp. On the top of the guitar is a thick piece of acrylic to help flatten the top and give me a good clamping surface. No damage being down to the finish. I used hide glue on everything.

Image

Once cured the result was immediate with the top. Some arch but none of the extreme doming it had before. When the bridge plate is attached it should flatten out a bit more.

Image

More to come.



These users thanked the author DanKirkland for the post (total 2): Clinchriver (Sat Jun 23, 2018 4:50 am) • Mark Fogleman (Fri Jun 22, 2018 4:48 pm)
Top
 Profile  
 
PostPosted: Sat Jun 23, 2018 8:22 pm 
Offline
Koa
Koa

Joined: Wed Feb 17, 2016 8:54 am
Posts: 665
State: Texas
Country: United States
Focus: Repair
After thinning the overlay down even further I added the bridge plate. Grain running diagonal as opposed to the horizontal lines from before. I also extended the width to go past the back edge of the bridge to prevent the dome top from returning after some time being strung to tension.

Image

I re-attached the back. I'm going to have it glued up first and then string to tension before I do any re-binding work. Mostly because if something goes awry it'll be easier to remove the back again and work with the binding already off. I doubt that this will happen but I enjoy covering that base anyway.

The top portion was still in rough shape. Lots of removed top material where the previous bridge resets had occurred. There was a significant "dip" where the top of the finish and the unfinished area sits.

To level out the top I decided to overlay another paper thin layer of spruce to give good gluing surface as well as to preserve the top from further damage. I could have glued the bridge to the wood that was already there with the scarf fill in place, but I do not want to see this guitar again until a long time down the road. I think that it was worth the extra effort. The spruce fill was thinned down and then scored lightly with the grain so that under pressure it "bent" to fill the little gaps between the scarf fill and the little dips in the existing top. I removed as much of the contaminated wood as possible and squared off the recessed portion slightly for the sake of good adhesion.

Image

Image

Tiny line of spruce is visible. I'll darken it up later. It's more important that there be wood to adhere to than to look absolutely insanely perfect for this instrument.

Image

Bridge is glued up now. Projection looks good. Thankfully no need for a neck reset in this one. Kind of excited to string this up and give it a test with the repairs that have been done.

More to come after the weekend.



These users thanked the author DanKirkland for the post (total 3): flemsmith (Sun Jun 24, 2018 9:50 pm) • Mark Fogleman (Sun Jun 24, 2018 4:29 pm) • Clinchriver (Sun Jun 24, 2018 6:04 am)
Top
 Profile  
 
PostPosted: Mon Jun 25, 2018 5:25 am 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Mon Dec 27, 2010 9:06 pm
Posts: 2739
Location: Magnolia DE
First name: Brian
Last Name: Howard
City: Magnolia
State: Delaware
Zip/Postal Code: 19962
Country: United States
Focus: Repair
Status: Professional
very nice!

_________________
Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/


Top
 Profile  
 
PostPosted: Mon Jun 25, 2018 12:34 pm 
Offline
Cocobolo
Cocobolo

Joined: Mon Jun 07, 2010 11:14 am
Posts: 109
First name: Jan-Alexis
Last Name: Tremblay
City: Montreal
Country: Canada
Focus: Build
Status: Amateur
That's great!


Top
 Profile  
 
PostPosted: Tue Jun 26, 2018 8:02 am 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Mon Dec 27, 2004 9:42 pm
Posts: 4216
Location: Buffalo, NY
First name: Robert
Last Name: Cefalu
City: Buffalo
State: NY
Zip/Postal Code: 14217
Country: US
Great work

_________________
Beautiful and unusual tone woods at a reasonable price.
http://www.rctonewoods.com/RCT_Store
The Zootman
1109 Military Rd.
Kenmore, NY 14217
(716) 874-1498


Top
 Profile  
 
PostPosted: Tue Jun 26, 2018 11:43 am 
Offline
Cocobolo
Cocobolo
User avatar

Joined: Mon Jan 14, 2013 3:25 pm
Posts: 239
Location: Bozeman, MT
First name: Tony
Last Name: Thatcher
City: Bozeman
State: MT
Well done!

_________________
Tony Thatcher
Bozeman, Montana


Top
 Profile  
 
PostPosted: Wed Jun 27, 2018 4:37 pm 
Offline
Koa
Koa

Joined: Wed Feb 17, 2016 8:54 am
Posts: 665
State: Texas
Country: United States
Focus: Repair
Bridge glue up went well. Sorry for the blurry pics my phone doesn't want to focus sometimes.

The belly is all but gone and now we just have the nice delicate arch in the top that we are after. In all likelihood this will probably still move and potato chip a little bit. But I've done all I can do at this point. With old guitars, it is what it is.

The tone is much better than when it had a giant hole in the top. I took a little sample on my phone but the quality is pretty low. I might link it later.

Image

Image

Image

All that's left is to re-attach the binding. Luckily it all came off in one big piece so it's just a matter of regluing it. Essentially it's complete sans the cosmetic issue of the binding.

I am happy with the result. I'm going to let it sit at tension for a week or two before I let the owner know that it's ready. So far so good. The owner I think will be pleased, considering this instrument's past with repair I can only hope that these repairs will outlive the owner or myself. Time will tell.



These users thanked the author DanKirkland for the post: Mark Fogleman (Thu Jun 28, 2018 10:00 pm)
Top
 Profile  
 
PostPosted: Wed Jun 27, 2018 6:24 pm 
Offline
Koa
Koa

Joined: Thu Nov 04, 2010 1:46 pm
Posts: 1880
First name: Freeman
Last Name: Keller
Focus: Build
Status: Amateur
Very well done and thanks for the show.


Top
 Profile  
 
PostPosted: Wed Jun 27, 2018 6:47 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Sat Mar 06, 2010 4:15 pm
Posts: 1690
First name: Joey
Last Name: Holliday
City: Pamplin
State: Virginia
Zip/Postal Code: 23958
Country: United States
Focus: Build
Status: Semi-pro
Dude- great job. Well done Sir!!! It's always awesome to see a skilled luthier breathe life back into what probably should have been a lost cause. I haven't done much repair work but this is inspiring.


Top
 Profile  
 
PostPosted: Sat Jun 30, 2018 1:53 pm 
Offline
Mahogany
Mahogany

Joined: Thu Oct 20, 2016 7:22 pm
Posts: 88
First name: Nathan
Last Name: Peirson
Country: USA
Focus: Build
Status: Amateur
Great job and very inspiring. What do you think the tonal difference is now with the extra wood added...anything noticeable?


Sent from my iPhone using Tapatalk


Top
 Profile  
 
PostPosted: Sun Jul 01, 2018 5:54 pm 
Offline
Koa
Koa

Joined: Wed Feb 17, 2016 8:54 am
Posts: 665
State: Texas
Country: United States
Focus: Repair
nathanpeirson wrote:
Great job and very inspiring. What do you think the tonal difference is now with the extra wood added...anything noticeable?


Sent from my iPhone using Tapatalk


Thanks for the compliment.

In regards to the tone. Everyone that has heard it compared to what it was likes it. I really don't think it's fair to compare it to what it was previously because it really was not in a decent condition. There was very little wood to wood contact on the top which translates to not alot of transfer of vibration. The other issue with the tone was that the bridge plate was right at the edge of the bridge. So there was truly no resistance to the pull of the strings.

The tone before was not ok, but it was not the fault of the guitar. It was the fault of the previous repair guys using copious amounts of glue to hold the top together instead of wood. Wood always wins in this application.

I didn't mention it before, but the previous repair guy charged my client excess of 500$ to do the repairs. One reason I wanted to go the extra mile is because he had been really screwed on it before. Sometimes you just need to do what you need to do.



These users thanked the author DanKirkland for the post: nathanpeirson (Mon Jul 16, 2018 1:13 pm)
Top
 Profile  
 
PostPosted: Sun Jul 01, 2018 7:16 pm 
Offline
Contributing Member
Contributing Member

Joined: Sun Feb 17, 2013 4:58 pm
Posts: 1328
First name: Ed
Last Name: Minch
City: Chestertown
State: MD
Zip/Postal Code: 21620
Country: United States
Focus: Build
Status: Amateur
Great to see an old instrument brought back. How thick did the thin layer of spruce under the plate and under the bridge end up being?

Ed


Top
 Profile  
 
PostPosted: Mon Jul 02, 2018 9:04 am 
Offline
Koa
Koa

Joined: Wed Feb 17, 2016 8:54 am
Posts: 665
State: Texas
Country: United States
Focus: Repair
Ruby50 wrote:
Great to see an old instrument brought back. How thick did the thin layer of spruce under the plate and under the bridge end up being?

Ed


The overlay was about 22 thou when I installed it. Once the glue had dried I thinned it down farther. The edges tapered out to I'm guessing 10 thou. I wasn't insanely precise when doing this.

Before it was installed I just held the overlay up to the light and removed material where it looked thickest. Once in the guitar I flattened it out and then continued forward.


Top
 Profile  
 
PostPosted: Sat Jul 07, 2018 2:40 pm 
Offline
Koa
Koa

Joined: Wed Feb 17, 2016 8:54 am
Posts: 665
State: Texas
Country: United States
Focus: Repair
Update on this one. Client picked it up today. I let it sit at tension from the 27th of June till today. No movement in the top and no budging of the bridge. Seems to be ready for another few decades hopefully.

Client was happy to have it back in good shape.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 20 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 2 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