Neck dilemma

[Brian Evans]

I had glued up a three plank blank of mahogany for the neck for my current project, but I guess I got some snipe at the ends and the glue joints are failing for about an inch at each end of the blank. I've been toying with trying to fix it, but I think I am going to scrap it. I have a plank of lightly birds-eyed maple that I bought not having a plan for it, I could glue up a neck blank out of it. I'm slightly worried about another glue up - previous ones have not failed but I obviously did something wrong with this one. The alternative is to buy a new neck blank of mahogany or some other wood, and I would probably go with a one piece blank this time. I am leaning towards the maple, since this is a very traditional 1940's style archtop but have read that figured maple isn't as stable as others. Yet I see that all sorts of guitar necks are birdseye maple. I don't know what to do...

Brian

[David King]

Adjusting the planer or jointer that's causing the snipe seems like a logical starting point. Please tell us the make and model if you need help addressing this issue.

[Barry Daniels]

Figured maple's reputation for instability is overblown.

[Mike Conner]

My necks are 3 planks divided by walnut. For a guitar:
Curly maple 0.750" thick
Walnut 0.075" thick (same as guitar sides)
Curly maple 0.600 thick
Walnut 0.075" thick
Curly maple 0.750" thick

The necks have been super stable and I get the small relief needed without relying on the truss rod. I install the LMII double acting truss rod just to be sure. I believe the 3 pieces are the source of this stability.

As far as the joint failure, I have seen some snipe affects, but make the neck billet longer to allow for cutting this off. Each billet is designed to yield two necks. The 3" heel blocks are cut off the ends, then the billet ripped to create 7/8" neck shafts and 1/2 thick headstocks section.

And all this was probably more than you ask for

[Jason Rodgers]

My necks are 3 planks divided by walnut. For a guitar:
Curly maple 0.750" thick
Walnut 0.075" thick (same as guitar sides)
Curly maple 0.600 thick
Walnut 0.075" thick
Curly maple 0.750" thick

A025 - Curly maple and walnut neck blank.jpg

The necks have been super stable and I get the small relief needed without relying on the truss rod. I install the LMII double acting truss rod just to be sure. I believe the 3 pieces are the source of this stability.

As far as the joint failure, I have seen some snipe affects, but make the neck billet longer to allow for cutting this off. Each billet is designed to yield two necks. The 3" heel blocks are cut off the ends, then the billet ripped to create 7/8" neck shafts and 1/2 thick headstocks section.

B061 - Neck Billet Ripped into Blanks.jpg

And all this was probably more than you ask for

Dude, Mike, that's a brilliant cut plan on the neck glue-up! Aaaaaand, I just stole it.

[Mike Conner]

Thanks Jason! I'm glad you can use the idea for your own builds. I have not seen this billet method posted anywhere else. There is more detail in my Archtop Build Journal posted here on MIMF:
http://www.mimf.com/phpbb/viewtopic.php?f=59&t=3905

I have a 4th edition in draft right now and can send you a copy - just PM me your email info. I have found lots of interesting and helpful information online, especially here at MIMF, and the Journal is my attempt to give something back.

[Rodger Knox]

Figured maple's reputation for instability is overblown.

Also been my experience. Out of the 20 or so necks that I've built (all laminated), only three did not have any figured maple, and one of those has a curly maple fingerboard.

[Michael Lewis]

You have to check the mating surfaces of the joints before you glue them. Now that you have had an issue with snipe, no matter how small, you will be checking for it on every neck you make. The same goes when gluing your wedges together for the top and back plates.

I have a quick and dirty method of dealing with such joints, I put a strip of self stick 180 grit on my jointer infeed table, and just push the fresh cut surface on that clean grit. You will see pretty quickly whether you have a flat surface. This gets rid of any little ribs left from nicks in the jointer blades too.

In the 40s and early 50s Epiphone used walnut for some necks. It's a great substitute for mahogany, and I like it very much.

[Brian Evans]

I glued up my maple neck yesterday, resorting to hand scraping to a final fit. I have no idea why but neither my jointer, thickness planer or any of my hand planes could do anything with this wood. A freshly sharpened scraper was peeling beautiful tiny shavings. Go figure. My theories are I've forgotten how to adjust and set up machine tools, all my straight edges have gotten bowed, I no longer know how to sharpen blades, the wood was frozen (it was cold in my machine shop) or the variable nature of the birdseye maple's density is harder to learn how to deal with than I was expecting. Regardless, the job is done and I will see what results I got when I start to machine the neck today.

[Barry Daniels]

Sounds like humidity may be an issue. Do you measure and control RH in your shop?

[David King]

Birdseye maple sometime doesn't shear off cleanly and the eyes will poke up a bit from the surrounding wood and cause the out-feed end of the board to gradually lift up as it passes through the jointer. Going to a spiral head with carbide inserts eliminated that issue for me.

[Brian Evans]

My work shop is heated to between 35 and 55 degrees, depending on if I am in there or not, and humidity is 45% right now. My machine shop is unheated and it's currently around 20 degrees out there. I am just getting terrible inconsistency with this wood, so I quit trying and went to the scraper, which worked out fine. I think the blade setup is what the problem is, they probably need to be reground. I have zero issues with mahogany, I can't machine this maple to save my life.

Brian

[Barry Daniels]

With that much swing in temperature and no active systems to control humidity I would expect wood movement. You have to control the temperature and RH to ever have a hope of less wood movement. It's just a fact of life.