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  #1  
Old 02-02-2016, 08:16 PM
stoneaxe stoneaxe is offline
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Default Help me replace a neck on this Gallagher.

A while back I posted my woes with this Gallagher 71 special.

Basically, the neck is twisted and bowed and no joy from the company, even though I am the original purchaser. So I had a local luthier pop the neck off for me, and lo, the truss rod (compression type) was doing exactly what I suspected- the anchored end is pulling through the end grain of the neck. It did not help any it was not centered in the neck, I think the apprentice built it...

So-since I do not want to spend $1500 on a new neck, and I am a pro fine furniture woodworker, I am going to build it. I have also built a few nice electrics from the ground up, many years ago. I have a new board and truss rod (double acting) and the woodwork is no problem-

Can you help me on sequencing the job?

Here is my proposed sequence - mark centerline on body and neck blank.

Build a routing template for the dovetail, male and female, and clean up the female which has shims etc in the pocket.

Cut the dovetail end of the neck blank to 89 degrees (is 1 degree enough?) and route a test piece, check the neck angle, , then do it for real, and fit the dovetail to the body. I am going to leave the entire neck blank an inch long, in case I need to cut off the dovetail and do it over.

After double checking up the neck -body joint, and checking for angle, cut the truss rod slot while the blank is still square, then profile the neck.

Question- is the neck normally glued into the body first, then the FB glued on ? Is the FB normally fretted before gluing on the neck?

finish the neck contour, headstock overlay ,tuner holes etc and finish the neck , then glue it in. (what sort of glue?)

The neck blank is a two piece of honduran , with the glue joint vertical through the neck centerline - the grain is 45 degrees on each side of the center line, it will form a chevron through the heel. I could resaw this and do a stack lamination, or stack the heel and scarf the headstock.

What do you all think? What obvious problems have I missed?
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  #2  
Old 02-02-2016, 09:43 PM
charles Tauber charles Tauber is offline
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Quote:
Originally Posted by stoneaxe View Post
After double checking up the neck -body joint, and checking for angle, cut the truss rod slot while the blank is still square, then profile the neck.

Question- is the neck normally glued into the body first, then the FB glued on ? Is the FB normally fretted before gluing on the neck?

finish the neck contour, headstock overlay ,tuner holes etc and finish the neck , then glue it in. (what sort of glue?)
I find it much easier to leave the neck un-profiled while gluing the fingerboard. My preference is to shape the neck only after the fingerboard is glued to the neck.

I find it much easier to profile the headstock and drill tuner holes while the neck is un-profiled.

Whether the fingerboard is attached to the neck prior to attaching the neck to the body is a matter of preference. It is also a matter of preference whether or not to finish the neck - with the fingerboard already attached and the neck profiled - prior to attaching it to the body or after being attached to the body.

It is generally easier to do the finish work, including filling, sanding and buffing, if the neck is not already attached to the instrument.

You might also consider a bolt-on neck arrangement, rather than a dovetail. It could be a butt joint or mortise and tenon arrangement. Nothing much, but tradition, is gained by the dovetail, and it is tedious to fit correctly. If you do stick with a dovetail, if it is a tight mating fit, you can use a single wood screw, with no glue, to attach the neck. The fit of the joint holds the parts in position: the screw simply prevents lateral separation of the two parts. (The extension of the fingerboard is still glued to the top.) If not a tight fit, just use regular yellow glue. You could use hot hide glue, but there is no clear advantage to doing so. Don't use epoxy or CA glue.
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  #3  
Old 02-02-2016, 09:55 PM
difalkner difalkner is offline
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I'm curious as to why Gallagher isn't responding to take care of this...
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My Woodworking YouTube channel - David Falkner Woodworking --------------------------------------------
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  #4  
Old 02-02-2016, 11:29 PM
stoneaxe stoneaxe is offline
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Quote:
Originally Posted by difalkner View Post
I'm curious as to why Gallagher isn't responding to take care of this...
They would not warrantee it, Steve said he would repair it for about 1200-1400, but the guitar sat in his shop for eight months and he finally admitted he had no idea when he would get around to it. I don't really think he wanted to get involved.
I bought the guitar from J.W. back in 1973.
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  #5  
Old 02-02-2016, 11:36 PM
stoneaxe stoneaxe is offline
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Quote:
Originally Posted by charles Tauber View Post
I find it much easier to leave the neck un-profiled while gluing the fingerboard. My preference is to shape the neck only after the fingerboard is glued to the neck.

I find it much easier to profile the headstock and drill tuner holes while the neck is un-profiled.

Whether the fingerboard is attached to the neck prior to attaching the neck to the body is a matter of preference. It is also a matter of preference whether or not to finish the neck - with the fingerboard already attached and the neck profiled - prior to attaching it to the body or after being attached to the body.

It is generally easier to do the finish work, including filling, sanding and buffing, if the neck is not already attached to the instrument.

You might also consider a bolt-on neck arrangement, rather than a dovetail. It could be a butt joint or mortise and tenon arrangement. Nothing much, but tradition, is gained by the dovetail, and it is tedious to fit correctly. If you do stick with a dovetail, if it is a tight mating fit, you can use a single wood screw, with no glue, to attach the neck. The fit of the joint holds the parts in position: the screw simply prevents lateral separation of the two parts. (The extension of the fingerboard is still glued to the top.) If not a tight fit, just use regular yellow glue. You could use hot hide glue, but there is no clear advantage to doing so. Don't use epoxy or CA glue.
So you prefer to glue the fingerboard to the neck prior to gluing the neck on the body.
That sounds like good advice, as well as the edge of the finger board providing a positive profile line to work to while shaping.

Any advice on how much neck angle to use? I am a bit unsure about where a straight edge laid on the FB should rest at the bridge. - and of course too much angle and there will be a definite bend in the FB where it transitions from the neck to the body.
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  #6  
Old 02-03-2016, 07:10 AM
redir redir is offline
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I like to have the FB glued on before mounting the neck too but I always fret the guitar after gluing the neck in. $1500 seems like a lot to me for a new neck.

But anyway, you should be able to measure the neck angle. In reality though you will just be getting close to that and then make adjustments from there. It's just basic geometry but in a nut shell, ideally you want the strings at the saddle to be 1/2in above the sound board. So take into consideration FB thickness and fret height and an ideal action of 4-5/64ths over the 12th fret down the center line and lay it all out on paper and figure out what that angle should be.
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Old 02-03-2016, 11:00 AM
Halcyon/Tinker Halcyon/Tinker is offline
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I route the truss rod slot while the blank still has square edges. I use a dado on the tablesaw using the fence. Then I have a jig for finding the centerline that keys into the truss rod slot. I set the back and forth angle as well as the side to side angle while the end of the neck is uncut. Then, those micro adjusted angles will be translated into the dovetail as long as you route square to that face. Always angle the neck a touch forward as it is much easier to pull a neck back than forward.

Then I glue on the fingerboard, carve the neck, finish it, drill tuner holes, attach to body, radius and fret.
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Old 02-08-2016, 08:21 PM
stoneaxe stoneaxe is offline
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Thank you all for the help. At long last I am cutting wood on this project.

Progress.
I have made templates and rerouted the body dovetail- it was 1/8" off the bodyline center. Then routed the neck dovetail to match.

At this point, there is a 2 1/2"wide by 4" thick Hon.Mahogany chunk of wood fit to the body. It is on centerline, the dovetail fits well, no play. The "chunk" has been cut back to within 1/8" of the final neck size , at the dovetail- just enough to check the fit of the neck to the body sides. Other wise it is a big rectangle.

Questions-
Right now, the neck is .062 above the soundboard, pulled up snug with a gentle clamping. (one light creak ) Because the neck blank may move after the bulk of the material is bandsawn away, I am inclined to rough bandsaw the neck shape and then check for warp or twist. If there is any, that .062" "extra" can be used to correct. The sides of the neck will be left square and straight at this time.
Even if it does not move at all, the plan was to use the jointer to remove the .062" , rather than fiddling with the dovetail. The jointer can also be used to add or subtract neck angle if necessary, by taper cutting.

With the neck blank pulled into the dovetail, and the .062" space corrected, and fretboard and frets accounted for, a straight edge laid on the fretted board would show about .025" above the bridge with no saddle in place.

The bridge is .320" thick, plus .025" = .345", as the height of a straight edge placed on the frets, above the soundboard, at the bridge. I will go lay this out with the measurements redir suggested.

Any comments or advice will be appreciated!
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  #9  
Old 02-08-2016, 08:45 PM
stoneaxe stoneaxe is offline
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  #10  
Old 02-09-2016, 12:03 AM
stoneaxe stoneaxe is offline
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How off center the factory dovetail was, and my quicky dovetail jig. MDF and screws, gotta love it for fast jigmaking. When I built custom furniture I rarely reused a jig, so speed usually trumped durability. The dovetails were cut with a 1/2" x14 degree bit with a 1/2" bearing. Angle of the dovetail V was 11 degrees, don't ask me why, it was just copied from the original so as to have minimum stock removal.

Neck blank dovetailed in.

Other half of the quicky dovetail jig.

view of the neck blank and fit, the FB is just clamped on to get some idea of angle. The notch in the blank is not the dovetail, but a section cut away to approximate the shape of the neck, so as to check the fit better. The 1/16" proud of the neck is visible here.
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Old 02-09-2016, 04:25 PM
funkymonk#9 funkymonk#9 is offline
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Stoneage, Congrats on your effort thus far.
I have a few concerns/comments for you, which may become more illuminated by another more experienced builder.

1. I think with or without the fingerboard, it would be easier and more effective to get the neck a bit closer to the final dimensions, taking into account typically the truss rod is routed while the neck face is still square.
2. Couple extra inches in length and maybe up to ¼ over thickness, and closer to actual dimensions about 3-4 inches past the dovetail. This will allow you to see how tight the actual fit is.
3. The fingerboard is glued on afterwards when you want to play it safe and make sure it is centered on the neck, if you glue it on first, you better make sure the dovetail fit will glue in perfect, although you can leave the fingerboard a little wider as it goes to the headstock so you can correct the straightness of the fingerboard.
4. As far as the angle and how much neck you have above the dovetail, one consideration is how the body/neck may move/change the angle once the string tension is added. Typically with a new guitar, a compensation measurement is added above the bridge height to allow for movement. There is an equation somewhere but generally it is around .125. This may be different because your guitar has already broken in.
5. You should have the actual fingerboard width drawn on the face and use those sides to run down the neck to the bridge, they should be equal distance from the center of the bridge, if the neck is indeed centered.
6. As far as the grain orientation goes, I’m not sure 45 degrees into a chevron is ideal. A quartersawn face and stacked heel or scarfed headstock is perfectly stable.
7. Bravo though, it is a good idea, it is hard to imagine all the little details which make it easiest and/or efficient.
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Old 02-09-2016, 05:43 PM
stoneaxe stoneaxe is offline
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Thanks for the encouragement!

Yes, gluing the FB on later would be safer as far as giving one last chance to align it- that seems like a good bet.

Thursday I will have a new bandsaw blade and will dado the truss rod slot then cut the neck to a bit oversize, then see if it changes shape and what the fit is like.

The neck was made from some 6/4 honduran I had laying around for ten years or so- it is nice dense old stock with a bit of ribbon figure, not ideal but if it does not end up well, at least I will be able to build a new neck..!!!

The grain is about 30 degrees off the quarter, originally I was going to laminate a contrasting strip down the center , then figured if I got the neck even slightly off center it would stand out something awfull! Stack laminating it may have been a wiser choice- one way to find out.

The layout on paper has the strings 5/32" to 3/16" above the bridge, with a dead flat neck and FB.. This is with 1/16"+ space at the 12th fret. This seems like it should be a workable angle, as with a little bow in the neck that height should drop a little, yes?

Do double acting truss rods normally get installed with the U shape up, or inverted?
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Old 02-09-2016, 05:59 PM
stoneaxe stoneaxe is offline
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A few more questions for the luthiers-

This Gallagher has a oddball 25 3/16" scale length. I have a nice new board Gallagher supplied- would you folks use it, or switch to a standard Martin scale length? Since I am making a new neck anyway, that could be done easily enough. Not sure if there would be any advantage or not.

In any case, to ensure correct intonation, should the nut end of the finger board be placed at the exact scale length, or a fraction longer? And since the bridge saddle is slanted, where would one measure to?

Are there advantages to landing the nut on the fingerboard flat as opposed to the headstock flat? Or is it just whatever is customary in a particular shop?

Thank you all for your advice and patience- this is all new to me.
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Old 02-09-2016, 06:06 PM
funkymonk#9 funkymonk#9 is offline
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I wouldn't worry about the strings above the bridge, generally with a straight edge on the centerline of the fingerboard it should hit the top of the front of the bridge precisely. This is with string tension.
The general set up including nut, fret and saddle set up will be fine if you get this earlier measurement right.
If by U shape you mean the nut in which to adjust the rod, it lays flat on the bottom of the routing slot.
Are you having the adjustment done at the headstock?
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Old 02-09-2016, 06:13 PM
funkymonk#9 funkymonk#9 is offline
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I would stick with the scale length as that is what the bridge and saddle placement is designed for, otherwise you may have to fill and rerout a new saddle slot.

The nut front should be right on the scale length measurement, although if your wanting to compensate the nut for intonation, the low E side would be moved forward a smidge not back.

As far as nut location on flat or slanted, i don't know of any advantage either way, some may say the break angle creates a different tension, but i do know the slanted slot at 15 degrees or whatever is a good bit harder to do right for a good fit.
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