New neck on a Martin question

[Ben-Had]

Originally Posted by gitnoob

Nice work -- I need to try that wedge trick.

Yeah, works great. Just lift enough to get the glue in and not it separate the brace anymore.

[Ben-Had]

I got the neck glued on yesterday and the center line and FB projection are right where I want them and the fit is pretty good after it's second reset. I will start on the FB leveling and compression fretting today.

[redir]

Looks like a nice clean reset. Did you shim that extension too?

[Ben-Had]

Originally Posted by redir

Looks like a nice clean reset. Did you shim that extension too?

Yes. I had a hard time trying to match the FB color. I must have looked at 200 pieces and none suited my so I opted to match the color to the top. It blends in pretty well (actually it looks like a better match in person than in the pic).

[redir]

That looks great Ben. Good to go for many many years after this one.

[Shugaboy]

Looks great Tim - I cant wait to play it!

[Ben-Had]

OK, I refetted this morning. I started out by measuring how much pull was on the neck strung and unstrung (before I yanked everything out) and got .012 movement in the neck. I'm shooting for between .003 and .006 neck relief strung up when I'm done. So I need to put .006 to .009 backbow in the neck to get there.

I start out by putting a fret in at 1st and 11th fret with a tang of .0195 width (about the size of my slot). I take a measurement at the nut location and get .038 (I have a .025 stacked under the .013 feeler gauge). When I'm done I want to hit between .044 and .047 to get my target relief.

Now using tang widths of .0225 and .0245 I fret the 2nd through 10th frets, checking the height after each is installed. I end up at .046 or a .008 difference. With the neck pull that should bring me in at around .004 neck relief which is where I want to be.

[gitnoob]

Very cool. I have an old Harmony with no truss rod that could probably benefit from a compression refret. How many tang widths do you typically use, just the two?

[Ben-Had]

Jescar supplies Martin fret wire (FW37080) in - .0185, .0195, .0205, .0225, .0235, and .0245. Then it depends on slot width and how much relief you need. I used .0195, .0205, .0225 and .0245 and this job. You're not going to get the neck to move huge amounts.

[Ben-Had]

I totally forgot I made this neck relief gauge (tells how often I use it) but I thought you may find it interesting to see a comparison of it and feeler gauges.
If it's flat it reads "0", relief goes toward the "90" side and back bow goes toward the "10" side. Right on the dime (well the 8)!

[charles Tauber]

Originally Posted by Ben-Had

So I need to put .006 to .009 backbow in the neck to get there....I used .0195, .0205, .0225 and .0245 [fret tang sizes] and this job.

Just to be crystal clear, you have a guitar with no adjustable truss rod, that you are refretting and you need to put a .006 to .009 back bow in it prior to stringing? And to accomplish that you are using 4 different fret sizes for compressing fretting?

I'm not criticizing your approach, but I'm wondering what advantage that has over cutting-to-the-chase and dressing the fingerboard to have a .009 back bow and then fretting in kind with the original frets - or, if possible, even reusing the original frets if they are good condition?

[Ben-Had]

Originally Posted by charles Tauber

Just to be crystal clear, you have a guitar with no adjustable truss rod, that you are refretting and you need to put a .006 to .009 back bow in it prior to stringing? And to accomplish that you are using 4 different fret sizes for compressing fretting?

I'm not criticizing your approach, but I'm wondering what advantage that has over cutting-to-the-chase and dressing the fingerboard to have a .009 back bow and then fretting in kind with the original frets - or, if possible, even reusing the original frets if they are good condition?

Well that certainly is one approach however, taking off wood to achieve a back bow removes more than just flattening it and by taking more wood off it could possibly increase the board’s flexibility, my training has taught me that a compression refret is not just to obtain the proper relief but can stiffen a neck that is too flexible adding tone, sustain and volume.

The square tube in 70’s Martins are known to be a little too flexible (in the vein of the ebony bar used during wartime) and as the owner stated he felt he was losing tone, volume and sustain I felt this was the best approach. The frets were worn and needed replacing as well.

I strung it up this morning and obtained the relief indicated on the gauge. Not exactly where I predicted but absolutely in the range I wanted for neck relief on this guitar.

[charles Tauber]

Originally Posted by Ben-Had

Well that certainly is one approach however, taking off wood to achieve a back bow removes more than just flattening it

True, but you're talking .009" of back bow. Not an appreciable amount of wood that is going to alter the stiffness by a significant amount.

my training has taught me that a compression refret is not just to obtain the proper relief but can stiffen a neck that is too flexible adding tone, sustain and volume.

Excellent.

After doing the work, are you able to hear any difference, before and after, in tone, sustain and/or volume? Just curious and wanting to learn from your experience.

[Ben-Had]

I let you know when complete and the owner has played it, he certainly knows the guitar better than I.

There is an issue with the saddle slot that I could not see with the old saddle in as it was cut so low. But the sides are not parallel to the bottom and it is causing a forward lean to the saddle. I have to take care of that issue first.

[Ben-Had]

Slot rerouted, guitar done.