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Great thread gang. Thanks. I don't know why, but I have always had an aversion to scarf joints and stacked heels. I think I had rationalized that they are: 1. Less strong, 2. Look cheap, and 3.) in some way cheating (don't ask) . . . BUT I am really evolving on this topic. 1.) In about 10 years of doing repairs I have never seen a failed scarf joint (of Type 1 or 2 above). 2.) I have had the opportunity to play some really fine sounding guitars that had stacked heel and scarf joint - I once passed on an OM-28 knock off for this reason, but I still think about how great it sounded (silly me). 3.) Having done a few repairs of sheared or destroyed headstocks the only reasonable way to complete the repair was to do a version of Type 2 (above) - and with a little creative sun-bursting the repair ended up invisible.

As I look at my wood pile I am really thinking that the most efficient use of neck stock is to scarf and stack.
Do you think there is snobbery about this topic in the general public - as in, "This is not how xxxx does it," or is it a case of just what I am used to seeing?

Anyway, thanks for the great thread, it has been very thought provoking for me.

Regards,
GS

The acoustic guitar industry runs on snobbery

I always use scarf type 2. Usually starting with 1x3" neck blanks from luthier suppliers (Hibdon black walnut is my favorite). If I can find 30-36" length blanks with no flaws, then I can get two necks by cutting a scarf in the middle, and cutting the headstocks from lower grade wood (no sense wasting the best stuff where it isn't needed).

For some reason the horizontal seams in a stacked heel bother me, but the seam for a single glued-on heel block doesn't. A vertical seam in the center doesn't either. So my standard heel is made from two pieces (again, lower grade wood) glued vertically. 3 piece can also be very stylish.


The only time I'd do a one-piece neck is for flamed maple, because seams in figured wood are ugly. But I'm skeptical of the stability of figured woods for necks, and giant blocks of highly figured maple are too expensive, so I don't expect it's something I'll ever do.

Wow, Dennis that vertically stacked heel is a very cool look. Real food for thought. The pursuit of efficient use of wood, from sustainable sources, is a worthwhile goal. But the comments about snobbery in the acoustic guitar world are very true. The most "valued" guitars are those built with the most wasteful methods and non-replacable materials. Do they sound better? It is great when you see an instrument which is enriched with ideas and careful workmanship, rather than rare wood and glitz.

For efficient use of wood it's hard to beat the 'traditional' Spanish stacked heel and V-joined head. In fact, a lot of what they did makes most sense if you think that wood was expensive and labor relatively cheap. The V-joint (not the same as Martin's modified bridle) is the best way to put on a head, IMO, but it's also a lot of skilled work. The scarf is not far behind in economy of wood use, and structurally pretty close. It's not as nice to repair, since, when you drop the guitar, you break wood.

Try as I might I somehow have never been able to understand the geometry of a v-joint. But I love the look. Now I know it’s efficient, so I guess I’ll have to give it another stab at figuring it out.


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Another type of joint that can be used is what I would call a "hidden scarph" joint. It's similar to what is used to reattach pegheads when violins are renecked. It has some of the elements of the modified bridle joint but is simpler to make and fit. In it's simplest incarnation the peghead has a straight sided "ramp" cut in the face (which is covered by the face veneer) and the neck shaft has a corresponding angle cut along it's upper end.
If the peghead is thick enough the join will only show under the "chin" as it does on fiddle necks. Although the "flat" surfaces are not as large as those of the conventional scarph, the "sides" of the joint would add more gluing area. For thinner "paddle head" type pegheads the joint could be finished off in a number of different ways, some of which would add even more gluing surface without much additional work.

One advantage to this method (separate peghead) is that the neck shaft can be cut with a taper and to closer final dimension (2 1/2" on one end 1 3/4" on the other) allowing two neck shafts to be nested and made from narrower stock (4 1/4"+) and from potentially thinner stock. It can make the neck a little "greener" and less wasteful of material.

RLRhett wrote:
"Try as I might I somehow have never been able to understand the geometry of a v-joint"

There are actually two ways to make that joint. One is a "covered V", where the "V" isn't seen from the front of the peghead - even without an added face veneer, and then there is the through cut "V" where the "V" is seen from both sides until a peghead veneer is added to the face of the peghead. David Schramm has some you tube videos on the covered "V" and Robbie O'Brian covers the Through "V". One difference I have noticed that the "Old Timers" did was to angle the sides of the "V" (like a dovetail)to make it lock into the peghead even without glue.
I think of those joints as a variation of the dovetail and half blind dovetail joints.

The big advantage of the parallel sided V-joint is that if the head takes a knock, as they do from time to time, what breaks is the glue line, not wood. At least it does if you use hide glue. I've encountered this and have heard of it happening on other guitars. The fix is simplicity itself: clean up the old glue, put on some new, and stick the head back on. Six hours later nobody will know it ever 'broke'.

"The big advantage of the parallel sided V-joint is that if the head takes a knock, as they do from time to time, what breaks is the glue line, not wood."

That is assuming the glue joint is weaker than the wood. I guess by that reasoning a poorly fit joint is better than a well made one.
There are advantages and disadvantages to all the different methods of neck construction. Even the one piece neck, somewhat maligned
for it's waste of material and weak neck to peghead transition, at least has the advantage of not relying on glue (which can fail over time) to hold itself together.

I think that in the case of the v-Joint, all the glue surface has a fair degree of endgrain orientation. The glue joint ends up being plenty strong for the application but unlike a fully sidegrain joint, not stronger than the wood. I could be all wet on this one though. . . I’ve never done a v-Jiont, i’m Not confident enough in my chops to make it properly.

_________________
Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Hide glue is quite strong, but has lower shock resistance than wood. Builders use this characteristic all the time to advantage. It holds well for normal loads, and if the load limit is exceeded 'slowly' the wood will break first. Under a shock the glue tends to crack. Again, I have seen this on my own guitars a couple of times, and heard reports of it with other instruments. At any rate, a well made V-joint is loaded in compression and shear which most glues that don't creep handle well.

The scarf joint is in shear and has a peeling stress on it. When glued with hide glue these will also fail when shocked, putting the load on the face veneer, which is seldom able to take it, especially considering that the static string load is also there. The face veneer breaks. I've seen this, too, back when I did more repairs. I've seen scarfs assembled with 'modern' glue that peeled up simply from the string load, when the head piece is below the neck shaft. When the head is above the neck shaft cold creep of the glue tends to produce a bump in the fingerboard around the third fret or so where the scarf ends. I don't recall any of those actually peeling up, but I only started to see one made like that later in my repair career, and thus lack a large sample over a long time.

Alan Carruth wrote:
"The scarf joint is in shear and has a peeling stress on it. When glued with hide glue these will also fail when shocked"

That is good information and a good reason not to use HHG for scarph joints.
Please don't take my comments as critical of your methods. When it comes to joining the peghead I think our philosophies differ. Your's allows easy repair-ability, while my own thoughts are more toward a stronger initial construction. It is hard to make any part of the guitar bullet proof or guarantee that it will break in a set manner - so either way we hedge our bets at best.
With the modern adhesives there may be less need for the intricacies of the old joints and simpler methods may be employed. But I still think it needs to be pointed out that the modern incarnation is not the same as what was originally done.

I figure that lots of guitars get dropped or knocked off stands. It's impossible to make a neck and head that will withstand that reliably and not be 'way too heavy. Under the circumstances making it so that it's less likely to break wood when it breaks makes sense. I'll give you that a V-joint assembled with HHG is more likely to break under a given impact. However, the repair is so simple, and the likelihood of collateral damage is so much less, that it's worth it IMO. Other than the possible need for more frequent repairs, the main drawback of the V-joint is the labor it takes to make it. It's far more difficult and time consuming than a scarf joint.