Official Luthiers Forum!

Solely owned and operated by Lance Kragenbrink
It is currently Wed Jul 18, 2018 12:00 am


All times are UTC - 5 hours





Post new topic Reply to topic  [ 11 posts ] 
Author Message
PostPosted: Mon Jul 09, 2018 6:05 pm 
Offline
Cocobolo
Cocobolo

Joined: Fri Feb 10, 2017 11:09 pm
Posts: 204
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
I pulled the neck off of this dreadnaught to reset it.

I couldn't find the air pocket in the joint so I removed the fretboard at the 12th fret to see what I was dealing with and to make sure I had good gluing surface for reattaching the fretboard. The pocket was super small and full of glue so that's why I couldn't find it with my drill bit. Anyway the neck came off easily once the fret board was off. I re-glued the fretboard onto the neck, but now when I put the neck back into the pocket I have a gap of about .010, I can get that down to about .005 if I squish the neck back in with a clamp. Is this normal?


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


Top
 Profile  
 
PostPosted: Mon Jul 09, 2018 6:15 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Mon Aug 23, 2010 11:42 pm
Posts: 1284
First name: John
Last Name: Parchem
City: Seattle
State: Wa
Zip/Postal Code: 98177
Country: USA
Focus: Build
Status: Amateur
The gap at the sound hole is normal.. When you reset the neck you changed the neck angle relative to the body. Most neck resets tilt the neck in the direction that will give you that gap. You can either accept the falloff and clamp it down or make a small wedge.

The gap at the join is not normal at the end you need to refit the dovetail.

_________________
http://www.Harvestmoonguitars.com


Top
 Profile  
 
PostPosted: Mon Jul 09, 2018 6:18 pm 
Offline
Koa
Koa

Joined: Thu Nov 04, 2010 1:46 pm
Posts: 1277
First name: Freeman
Last Name: Keller
Focus: Build
Status: Amateur
While that is normal for a reset in the picture it looks like the gap goes all the way to the end of the body (14th fret?) That tells me maybe the tenon isn't all the way down in the pocket.


Top
 Profile  
 
PostPosted: Mon Jul 09, 2018 6:30 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Wed Apr 08, 2009 9:34 am
Posts: 2874
Part of a neck re-eset is getting the neck down to the top at the 12th or 14th fret. Check out John Hall's vid on dovetails...

_________________
J. Brentrup Guitars & Mandolins
http://www.brentrup.com


Top
 Profile  
 
PostPosted: Mon Jul 09, 2018 11:01 pm 
Offline
Cocobolo
Cocobolo

Joined: Fri Feb 10, 2017 11:09 pm
Posts: 204
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
I haven't actually done anything other than take the neck off and re-attach the fretboard portion that I had taken off.

I'll check out John Halls videos, I've been using the Dan Erlewine DVD as a primary resource with this but I intend to dig into a few more resources before plunging off the point of no return.

Should the joint slide back together easily or should there be resistance the further in the dovetail goes?

My first thought was that there was something impeding the tenon from going all the way into the pocket, I pulled the neck back out and cleaned out anything that was loose (or almost loose). There still may be some obstruction, I"ll take a closer look tomorrow. I did squeeze the joint back together with a clamp and reduced the gap to .005 as I said, but the feeler gauge wouldn't slide all the way in, and light no longer shows when you look through the gap. Is it possible that I compressed the wood on the edge with the knife I used when heating the fretboard off so it appears that there is more of a gap than there really is?

I was also worried that maybe I messed something up when I re-attached the fretboard to the neck, causing the fretboard to sit above the body but there doesn't seem to be any gap between the rosewood and mahogany...


Top
 Profile  
 
PostPosted: Tue Jul 10, 2018 9:25 am 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Wed Apr 08, 2009 9:34 am
Posts: 2874
Think we all presumed you had started the reset. Has the joint even dried out? Are you sure? Is all the glue crap scraped/sanded out and off?
The joint when finished should be tight enough to be able to pick up the instrument by the neck. It should "tap in" with a few taps of the mallet. Make the wooden sanding block John shows...

_________________
J. Brentrup Guitars & Mandolins
http://www.brentrup.com



These users thanked the author Haans for the post: pat macaluso (Tue Jul 10, 2018 9:53 am)
Top
 Profile  
 
PostPosted: Tue Jul 10, 2018 3:51 pm 
Offline
Cocobolo
Cocobolo

Joined: Fri Feb 10, 2017 11:09 pm
Posts: 204
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
Here's a couple pictures of what the neck looks like after re-gluing the fretboard. Does this look problematic?


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


Top
 Profile  
 
PostPosted: Tue Jul 10, 2018 4:10 pm 
Offline
Cocobolo
Cocobolo

Joined: Fri Feb 10, 2017 11:09 pm
Posts: 204
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
a more thorough cleaning of the joint, there was glue squeeze out in the corners, the remnants of a couple old shims, and other bits of debris I hadn't noticed and this is what I have now. Where the neck joins the body I can't even get a .002 feeler gauge in the bass side, the treble still has a small gap but not much more. Seems much more reasonable...


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


Top
 Profile  
 
PostPosted: Thu Jul 12, 2018 3:50 pm 
Offline
Cocobolo
Cocobolo

Joined: Fri Feb 10, 2017 11:09 pm
Posts: 204
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
Well, I took a little material off and shimmed the pocket and restrung but still needed to go a little further. So off with the strings, and I took a little more material off the heel and I'm about to shim the pocket a second time, but I want to double check my logic before moving much further, there is a slight gap at the base of the heel, it seems to me that the shim(s) will deal with the gap by forcing the base of the joint to suck further into the joint, but I have trouble forcing it closed by hand even if I push on the headstock. Is this remedied by the introduction of the shims or do I need to do more work around the heel? I've noticed that the joint is flush by the fingerboard but the gap develops towards the heel cap, does it just need more sanding near the fretboard?


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


Top
 Profile  
 
PostPosted: Mon Jul 16, 2018 2:30 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Tue May 13, 2008 10:44 am
Posts: 3487
The gap on the fretboard extension looks to me to be a from the board curling. But it's probably a combination of curling and the new set angle. IF it is the set angle then you can simply make a shim for it. If it's cruling then if when you clamp it in place dry and there is no gap then just go for it. If not then you will probably have to sand it flat and probably do a refret.

You should be able to use the straight edge measurement to get the neck angle right. Just rest a straight edge dead center on the FB along the top of the frets such that it hangs over the bridge. Once the airspace there at the saddle is about 1/32ne inch (provided the bridge has never been shaved down) then you have the right angle.


Top
 Profile  
 
PostPosted: Mon Jul 16, 2018 9:00 pm 
Offline
Koa
Koa

Joined: Thu Nov 04, 2010 1:46 pm
Posts: 1277
First name: Freeman
Last Name: Keller
Focus: Build
Status: Amateur
It looks to me like you have altered the angle by removing material from the bottom of the heel cheeks. Now the dovetail is no longer tight, particularly at the bottom. Generally you have to shim the bottom of the sides of the joint more than the top, I glue the shims in then taper them with chisels and sanding blocks. It helps a lot to chalk fit them - you can see where you need to take away material.

I also think you have confused things a bit when you sawed the f/b off - frankly I would have left that off until the neck was set, then tried to glue it back in place over the joint and onto the body.

A well made dovetail just sort of slides into place with no wobbling or other movement. Frequently I'll have to give it a slight tap with a plastic hammer to set it (and tap the heel to get it apart) but you can tell when the wedging action is working. From your pictures you are not there yet.

edit to add - I am not an expert at dovetails, I've only done a dozen or so and I fight them each time. John Hall's vids are really good for teaching how they work and how to set them, there are others that are helpful too. One of the things I found really helpful was putting too thick of shims in (just like a new joint where the neck stands proud of the block), then shaving them down and watching the neck drop into the pocket. I also had the advantage of learning on a few new guitars before I tried resetting one that was really wonky.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 11 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 1 guest


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