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 Post subject: New neck for old guitar
PostPosted: Fri Oct 06, 2017 3:16 pm 
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First name: EddieLee
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I have a customer that has asked me to make a neck with a different profile for a guitar I made for him a few years ago. The neck is a bolt on mortise/tendon style with the fretboard extension glued down.

How hard would this request be to accomplish? I have never un-glued a fretboard extension, and that makes me nervous. The other thing I worry about is intonation. In a normal build, I glue the bridge down as the very last operation. That way I can set the scale length with some precision. Making a neck with the nut and fret 1 in the correct position without repositioning the bridge seems difficult.

I can imagine that the fretboard can be glued down with some precision by using locating pins. However, I always seem to need to floss the neck join after the finish is applied. I worry that this could take off enough material to cause an issue setting the intonation on the saddle.

Any comments and suggestions would be greatly appreciated.

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PostPosted: Fri Oct 06, 2017 3:29 pm 
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Others will chime in on the intonation aspect. I personally don't think you have anything to worry about with a little flossing.

Regarding getting the extension up, what was it glued down with? I have taken several off by applying heat from an iron or a heat bulb to that area and then using the SM bridge spatula to separate the extension from the top. If you use a heat bulb make a shield out of cardboard and aluminum foil to protect the area around the extension. If you use an iron just put it right on the frets and wait a few minutes. I use a veneer iron for this.

Hope that helps.

Brad

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PostPosted: Fri Oct 06, 2017 3:40 pm 
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Thanks Brad, The extension is glue down with fish glue. I have had good luck remove fish glued items in the past using heat and a little water. However, removing a fretboard extension make me very nervous. Probably a procedure I will need to learn to do sooner or later.

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PostPosted: Fri Oct 06, 2017 5:21 pm 
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Go ahead and replace the fretboard and neck as one unit.

You can fab it all up to his specs and then do the final fit on the guitar.

Fretboard extensions generally come up pretty easily assuming conventional glue.

On the intonation... So long as the scale is the same - the intonation compensation will be close. You will need to make a new saddle... But I would be tempted to try the old one first.


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PostPosted: Fri Oct 06, 2017 5:36 pm 
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I would fit the neck without the fingerboard, making allowances for the thickness of the board and frets. Gluing the fretboard down last would allow you to shift it slightly to get it in the correct position in relation with the bridge saddle. If you have room on the bridge you could widen the saddle slot (and saddle) to give a little more "wiggle room" for setting the compensation.

No chance you could modify the existing neck to give the desired profile?
For the work involved in removing the old neck and making and fitting a new one I would be inclined to try to sell him a new guitar.


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PostPosted: Fri Oct 06, 2017 9:29 pm 
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Thanks all, good comments. He wants a thicker profile so has to be a new neck. Clay, I was thinking the very same thing. It might be cheaper to get a new guitar and sell the old one.

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PostPosted: Sat Oct 07, 2017 4:48 am 
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Years ago, a guy walked into my shop and left with an "off the shelf" guitar. He liked the sound of it so much that over the years he bought a few more guitars (what a nice customer!), but they were custom built to suit him. Then one day he called me up and said he would like a new neck on the original guitar, of the same profile he had on his custom guitars. And "oh, how about some inlay, too?"

I said OK to all the above. Here's the original fret board end:

Attachment:
DSCF7916s.jpg

As the original guitar had my usual double tenon bolt-on, bolt-off neck, getting the neck off was easy:
Attachment:
DSCF4163s.jpg

Making the new neck was no problem, either, because of two things I always do:

1) The neck angle is set by the slope on the upper bout (which has to be built right), and when the neck and upper bout are co-planar, the neck projection over the saddle position gives the right string height over the sound board and the right action. So set the neck co-planar and you know its going to be right.
2) I always use the same thickness fret board.

So the procedure is to get the new neck set set up and co-planar (and check you can access the truss rod adjuster):
Attachment:
DSCF8057s.jpg


Then set the fret board on the neck in the right position. I have a jig that sits in the saddle slot and the nut slot to give the right distance. Set it in the saddle slot and move the fret board to the right position (and alignment). Clamp it there and mark the end of the fret board and glue on the head stock facing which acts as a stop for the fretboard. Also glue some small chocks either side of the fret board to fix its position. (I haven't got a picture of this).

The fret board can then be glued on with full confidence that it will be in exactly the right place with the right neck angle:

Attachment:
DSCF8215css.jpg


Looking at the original of this pic, with the yellowed Tusq saddle, it looks like I used the original saddle, but a new nut!

You're going to have a bit more hassle getting the original neck off, but the rest of the procedure should be much the same. If you don't build using the "co-planar" rule, you'll have to fudge around that. But you should still have a number for target neck projection over the saddle position. If you work to that (whatever it is) you should be good to go. I glue the board on with it fully fretted and rarely have to do any leveling later. That's one of the reasons behind the whole co-planar thing. However, if you execute your normal procedure, I can't see you having a problem.


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PostPosted: Sat Oct 07, 2017 9:16 am 
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I thought you said he wanted inlay. Why did you hold back?[WINKING FACE]


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PostPosted: Sun Oct 08, 2017 7:53 pm 
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Thanks Trevor. That is basically my plan. Happy to know that worked for you. I am not clear on what you mean by co-planar. I assume that is in your book. I will look it up. Love the bolt on bolt off neck.

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PostPosted: Sun Oct 08, 2017 10:14 pm 
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First name: Trevor
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EddieLee wrote:
I am not clear on what you mean by co-planar...

With the neck bolted on, a straight edge over the length of the neck and the upper bout shows no gaps, which means that the neck's top surface and the upper bout to the top of the sound hole are in the same plane. That plane, when projected over the saddle position, should give a particular clearance over the saddle position. I use 2.5mm clearance for a steel string guitar. This means that I get the right action and right string height above the soundboard when the fret board and frets are added. But it also means that you have to get the angle of the upper bout right in the first place, which is controlled by the amount of curvature you put on the upper transverse brace.

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http://www.goreguitars.com.au


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PostPosted: Mon Oct 09, 2017 1:00 pm 
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I just pulled a neck off one of my builds on Friday. Same set up - bolt on mortise/tenon with the fb extension glued with fish glue. I have a ski waxing iron that works great for pulling fretboards. I set it on top of the extension right on top of the frets on medium heat. I pulled the bolts which allowed the heel to pull away from the guitar slightly. Afrter about 15 minutes, the heat loosened the glue, and the gap slowly widened as the extension pulled up from the biding edge. No spatula necessary. Go slow. Don't force it.

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