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When The Scarf Joint Appears At The Throat.

Posted: Tue Jan 15, 2019 8:22 pm
by Gilbert Fredrickson
My two steel string guitars are scarf joint and stacked heels cut from 1"×3" billets. I think I thin them to 7/8" but it has been awhile since I've made one. The scarf joint on these guitar necks appear nicely at the start of the shaft side throat. Now, my classical guitar necks are also cut from 1"x3" billets but, on these guitar necks, the scarf joint is way up the headstock, noticable at the top of the throat by 1/2". It never bothered me before. I use a 1" blank dressed to 7/8", from the layout in the Sloan book. Why am I not getting the beginning of the scaft joint directly under the fretboard side of the nut slut? I'll be paying attention to this on a classical neck build I am beginning today. Thanks, any advice would be appreciated.

Re: When The Scarf Joint Appears At The Throat.

Posted: Tue Jan 15, 2019 9:05 pm
by Freeman Keller
Gilbert, there are obviously two ways to do the scarf joint - with the head piece below the neck stick and with it on the end of the neck stick. Obviously that will move where the glue line ends up and might be a reason to choose one over the other. I have done it both ways and mostly prefer putting the head on the end - that ends up with the line basically under the nut.

However that really isn't the reason I have chosen to do it that way. I fix a lot of guitars with broken heads - most of the time it is the short grain of the sawn angled head where the fracture occurs (often going into the route for a truss rod). My argument (to myself) is that with the head glued onto the bottom of the neck stick the weak point actually becomes my glue line, and yes, I know that the glue should be stronger than the parent wood but why risk it. If the head has been planed down (your classical will probably be thicker) I have a relatively small glue surface.

If I glue it onto the end I now have straight grain running the entire length of the head piece, a larger gluing surface, and lastly, the thick fretboard laminated on to to further strengthen it. I also try to minimize the cavity for the truss rod if I'm going to put it in the head. The only downside that I can see is that leveling the top of the neck thru that joint is slightly trickier.

Btw - I just made a neck for a new guitar and tried a new trick for the scarf joint. I have always had trouble holding the pieces in alignment while gluing the joint - I end up clamping a bunch of blocks of wood on my bench to act as stops and cauls while I preform my high school physics demonstration of the effectiveness of a lubricated wedge. Anyway, last neck I simply got everything lined up and clamped and drilled two little holes out of the way, spread the glue, put round tooth picks in the holes and applied clamps. Nothing moved and I don't have pieces of metal in there to grab a router bit. You can barely see the tooth picks by the orange clamps
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Re: When The Scarf Joint Appears At The Throat.

Posted: Tue Jan 15, 2019 9:50 pm
by Bill Raymond
If you are making your scarf joint at the end of the neck (not under the fretboard as Freeman does) the joint may be seen at the back of the head instead of at the throat, depending on the thickness of the neck blank where you glue the head. I have taken to thinning the neck blank at the head end to a point where the scarf joint will be right at the transition of the neck to the head where it will be almost unnoticeable.

Re: When The Scarf Joint Appears At The Throat.

Posted: Tue Jan 15, 2019 11:01 pm
by Gilbert Fredrickson
Freeman, I understand exactly whay you are talking about. As I was reading Cumpiano, preparing for this next guitar, I stopped and thought the scarf had been on top the first time I read the book. It makes perfect sense. Also, my first classical guitar has a headstock that tilts ever so slightly because on the four sides of the neck were not exactly square when I clamped it to the bench.

I see were I can carve up to the glue line, Bill. Thanks, it is important to get it close initially. I was just rolling along on my first guitar. The 1/2" above, on my personal guitar (#1) is due to a Gibson like, deep V carve. I could have carved further up. Unfortunately, I still can't remember how I did it right on the steel string guitars. It may have been through thinning the head piece before glueing up. I suspect it was an accident, as I wasn't paying attention to the glue line.

I just researched thirty or more classical guitars. I found one old Spanish master guitar that displays exactly what I'm talking about. It's not common, but there are a few others in history. The most heartening thing is that I found a modern copy of that (Simplico) Spanish master guitar by a favorite modern master that displays exacly an identical glue line. It's even exactly, identically, masterfully, off angle. So, obviously its very controllable.

Re: When The Scarf Joint Appears At The Throat.

Posted: Wed Jan 16, 2019 12:53 pm
by Clay Schaeffer
Tapering the neck blank from the fingerboard side can help move the end of the scarf joint to the "chin" of the peghead.

Re: When The Scarf Joint Appears At The Throat.

Posted: Wed Feb 13, 2019 1:56 pm
by Gilbert Fredrickson
Thanks, Clay. I did that. The results are good.

Re: When The Scarf Joint Appears At The Throat.

Posted: Thu Feb 14, 2019 9:59 am
by Brian Evans
I look up this website every single time I cut a scarf joint. I always forget how to do it between times....
http://www.mirwa.com.au/HTS_Headstock_Scarf_Joint.html

Re: When The Scarf Joint Appears At The Throat.

Posted: Thu Feb 14, 2019 4:05 pm
by Gilbert Fredrickson
Yeah. I haven't carved a neck in a year. Honed the chisels and -BAM- like riding a bicycle. Thanks for the link.