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Laminated necks & scarf joints
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Author:  Rod True [ Tue Feb 20, 2007 2:43 am ]
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Hey folks,

While I'm starting to think about the up coming outback guitar (that fine wood I won in one of the KG auctions from Australia Tonewoods) I have been thinking about the neck I want to make.

The Flamed Taz Blackwood neck with neck block requires a scarf jointed headstock and laminated neck block.

I would like to add some laminated lines to it, thinking about two separate lines so the laminations would go like this Taz/b/m/b/Taz/b/m/b/Taz
Middle Taz would be 1/2"
b=0.020
m=0.125

Anyway, The neck blank is 1" thick right now and all the other components are 4" wide.

So my question (sorry to take so long to get to it) is this.

I've done one laminated neck with scarf joint and stacked heal and didn't like how the lines lined up, I even used dowels to line it all up before gluing, but it still shifted during glue up.

So...... How do you folks who lam and scarf do it? Should I scarf and add the neck block first, than cut it and lam in the lines?

Thanks for any ideas and help.
Author:  Dave White [ Tue Feb 20, 2007 2:58 am ]
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Rod,

I've done the laminations and then "scarfed and stacked". As I do a backstrap on the headstock the lining up here isn't totally critical but the heel is. I used dowels (cocktail sticks actually) and glued on a layer at a time and also provided guide blocks at each side to make sure nothing moved while gluing. It just about worked but absolutely every piece has to be dead square with the lams right down the middle or else the line will wobble when you carve the heel (damhikt ). This one just about worked:



If the decorative laminations were wide enough (for the heel), now I would probably do the scarfe and stacked heel with the main wood and then cut the neck into three and glue it back with the laminations. Again you would have to jig-it up to make sure the 3 pieces plus lam come back to the right shape (or leave enough wriggle room for truing up) but this would probably look better.
Author:  Steve Saville [ Tue Feb 20, 2007 3:03 am ]
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Rod,
Make the Taz part with the scarf joint and heel. Cut of your middle section from this bland and clean it up on your thickness sander. Cut the remainder down the middle and thickness sand both sides so that they are the same thickness and square. Make blanks of the maple to match the profile of the taz. You might want to bond the Black layers to the maple or Taz before you try to assemble the whole thing.

Here are some pictures. Let me know if you need more help. It took me about 4 necks to figure this out. But it makes perfectly straight sections.




Author:  JJ Donohue [ Tue Feb 20, 2007 3:08 am ]
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Rod...I've never done a scarf joint so I can't comment on the question you pose.

Here's another option...use a horizontal lam on the back side of the headstock. That way you can use plain Taz, or if you decide to have the headstock laminated and you get off register, the back and top plates will hide the misalignment. Of course, the end grain would still show the vertical lams on the end grain.

Then again...maybe someone will reveal a fool-proof way to glue up the scarf joint without misalignment.



Author:  LuthierSupplier [ Tue Feb 20, 2007 3:08 am ]
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Hi Rod,
Funny you should ask. Just finished up a small concert Uke Neck. Curly koa with Cocobolo and maple. I tried doing it your way on my bouzouki and failed miserably. I had to get creative covering up that mistake. So I learned a good lesson...First go ahead and glue the scarf joint and heel. Then rip down the middle and glue in your laminations. You will be much happier with this method, and impossible to get the lines to not line up. Just make sure you leave enough sticking out at the heel and peghead, and that everything is nice and flat on a good flat surface when glueing. Also, leave enough length and thickness of the neck in case things shift on you, and you have to plane the top of the neck to get everything flat. Good luck!
Tracy
Author:  Pwoolson [ Tue Feb 20, 2007 3:26 am ]
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Rod, on my early guitars, I did a scarf joint on laminated necks. Had a devil of a time getting them right so I went to one piece necks instead (still laminated but no more stacked heal or scarf joint).
I like Tracy's ides of ripping it down the center and laminating it after the fact. I think you would have to leave a significant amount of stock to get everything all trued up but it will look great when it's done.
Author:  j.Brown [ Tue Feb 20, 2007 10:02 am ]
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I build my neck with the scarf joint and the stacked heel as described in a couple of those posts above. Then I drill dowel holes, cut the whole thing in half, laminate with solid pieces of wood, line them up with the dowels, and clamp 'em.
-j.
Author:  Rod True [ Tue Feb 20, 2007 10:20 am ]
Post subject: 
Thanks guys for the help.

I'm thinking I'll do what most here do, glue up the scarf and heel, than rip it into three pieces and add my laminations.

J, I like the added dowels after glue up, that will certainly help.

Now, a second question.....what are you guys using for glue. I'm thinking I'll use polyurethane for this glue up. Paul, I seem to recall that you use poly glue for your neck laminations, yes?
Author:  Steve Saville [ Tue Feb 20, 2007 10:47 am ]
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I use LMI white or Titebond.
Author:  Shane Neifer [ Tue Feb 20, 2007 11:02 am ]
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Hey Rod,

I made a couple of necks stacked with a 1/2" maple cetre lam. I didn't like it, it lined up ok with out dowels and the lot, it isn't too hard if you keep everything square amd lay it up on it's side. But then, not liking the huge (1/2") centre strip, I cut the necks in half and added an 1/8" Nicuragran walnut strip, and I think that lamntaing after the fact is better. So glue it up, saw and re-glue. You don't need dowels anywhere, they will actually weaken your joint(glue starvation, removing availbale glue surface), minutally, but they do not give you any extra or needed strength and are foriegn bodies that you now have to avoid in your carving process.

You will no doubt make it look GREAT!

Shane
Author:  Mike Dotson [ Tue Feb 20, 2007 12:29 pm ]
Post subject: 
Make sure the lammed blank is run through the
jointer so it's square, then after you cut and prep the
scarf do the glue up on a very flat surface like a band
or table saw. I usually do a back strap and cover it,
but I still like to know the laminations line up.
Author:  j.Brown [ Tue Feb 20, 2007 1:23 pm ]
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I've used Poly on my last 2 laminated necks, and its worked great. Too much assembly for Hide Glue for me :)
-j.
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