First build... come laugh at my mistakes.

[warfrat73]

Yeah, definitely not making a trussrod from scratch.

But I sure dig their hair styles.

[charles Tauber]

Originally Posted by phavriluk

I think his book is on the wrong side of a half-century of stale shop practices (Anybody want to make a truss rod? Install a neck?).

That's probably true.

I stopped making my own truss rods about five years ago, when I switched to double-acting rods. I started using a radiused dish about two years ago. Neither of those existed when that book was written. Nor did gauged nut files, gauged nut saws and a pile of other more recent jigs, fixtures and tools. The book pre-dated the use of barrel nuts in guitar making, though the updates to the book switch from the Gurian-era pinned mortise and tenon to barrel nuts.

It presents an interesting opportunity to ponder how guitar making has changed since the book was written. Some things have changed a lot, others not at all. When I started making guitars, the only English language books on guitar making were Sloane's books, Overholtzer's and David Russell Young's: few today would consider those relevant.

[redir]

Now I feel old

I used Sloane's book for my first and then Cumpiano's was like the bible and now that is old too

Well, I still build in that style. Open work board construction.

[charles Tauber]

Originally Posted by redir

Now I feel old

I used Sloane's book for my first and then Cumpiano's was like the bible and now that is old too

Yeah, me too.

[warfrat73]

After a couple of busy weeks with work, I was able to do a couple of things on the guitar today.

Setup a makeshift go-bar deck.

Got the back braces glued on and rough carved. The one on the bottom swam a bit on me, and is a touch crooked but it has the virtue of being out of sight once the box is closed.

Used Spanish Cedar for no really good reason other than liking the smell.

I was going to add a seam reinforcement after gluing up the braces (I know that it's usually done first). But got to reading, and a number of folks say that they're unnecessary unless you're using a back-strip. Currently hemming and hawing on it.

[Vermelho]

Waaah! Enough surplus to make it into a florentine cutaway?
(edit - way late to this, and very spontaneous attempt at making light of the broken side). Looking good though! I'd considered making an acoustic guitar years ago when I had a bit more space & tools.

[warfrat73]

Got the back braces sanded and refined the shape a bit more and got the back kerfing installed. Some of it sitting a little more proud than ideal....all the warnings about not leaving it short coupled with ramped clamping surface making it want to squeeze up a bit. Just take a few more passes with the sanding board. The second side I did looks cleaner, learned a bit in the first.

It's always this point in watching other builds that I've always thought they started looking like guitars.

If things go smoothly I may have a closed box by the end of the weekend (though I suspect it will drag into next week).

I'm a bit nervous about routing the channel for the rosette and then the bindings... and then the whole neck thing...

[warfrat73]

Alright, fingers crossed. On the dry runs it seemed good and tight at the neck block, but on the real deal there was a touch of a gap that I couldn't seem to close up.

[warfrat73]

Well, the good news is that the glue joint seems decent.

The bad news is that that slight dissymmetry in the sides is going to come back and get me. I checked multiple times that the neck block was square with the centerline. But, taking it out of the mold and looking at it straight on with out the dowels cluttering it, it seems a bit askew, nut sure if it shifted during the clamping process. The treble side comes into the neck block nice and flat, but the bass straightens out closer to the block, doesn't quite come in at a curve.

I definitely think that having a rigid template to match the curves to, rather than a paper template would have helped get those more dead on.

I had also been having some problems with the dowels loosening up and moving out of position, which won't have helped.

I'm on the fence about whether this is catastrophic.
I guess I should be able to adjust the heel to compensate.

[Victory Pete]

Originally Posted by warfrat73

Well, the good news is that the glue joint seems decent.

The bad news is that that slight dissymmetry in the sides is going to come back and get me. I checked multiple times that the neck block was square with the centerline. But, taking it out of the mold and looking at it straight on with out the dowels cluttering it, it seems a bit askew, nut sure if it shifted during the clamping process. The treble side comes into the neck block nice and flat, but the bass straightens out closer to the block, doesn't quite come in at a curve.

I definitely think that having a rigid template to match the curves to, rather than a paper template would have helped get those more dead on.

I had also been having some problems with the dowels loosening up and moving out of position, which won't have helped.

I'm on the fence about whether this is catastrophic.
I guess I should be able to adjust the heel to compensate.

I had a crooked neck block once and with shims and some careful shaving I got a nice neck set on one of my best sounding guitars.

[charles Tauber]

Originally Posted by warfrat73

I definitely think that having a rigid template to match the curves to, rather than a paper template would have helped get those more dead on.

I was taught to use a heavy card stock for making templates. I've used that for four decades with no issues, but for the fact that they aren't waterproof where circumstances involve water. On occasion, I've also made acrylic templates.

The templates aren't a means of "holding" things in place.

In a traditional Spanish face-down construction, the templates are used to mark the outline of the top. The top is then shaped to final size and then the top, itself, is used as the template. In the method I was taught, the workboard and dowels, the dowels are then abutted to the top, itself, to define where the sides need to be: the guitar top is the template for the sides.

I had also been having some problems with the dowels loosening up and moving out of position, which won't have helped.

The dowels that I use have square ends, allowing them to sit perpendicular to the workboard while also providing a solid base of contact with the workboard. I use wing nuts and washers on the bottom of the workboard to fasten the dowels in position. I've never had any issues with them moving or slipping once fastened.

I'm on the fence about whether this is catastrophic.
I guess I should be able to adjust the heel to compensate.

It's likely not.


Most guitar backs have an arch in two directions. The braces provide the arch across the width of the back and the side contour provides the arch along the length (longitudinally) of the back: the back is forced into the longitudinal curvature.

When the back is glued to the sides first, the forced longitudinal arch in the back will try to flatten if/when removed from any restraints. Doing so will distort the sides, "splaying" them towards the less-restrained surface to which the top will be glued. If you glue the top to the sides in this condition, you will end up with an unplayable guitar: the top will be distorted and the geometry won't work. (Don't ask me how I know this.)

This situation can be avoided by gluing the sides to the top, top face-down on the workboard before gluing the back on: glue the top on first, then the back. (The workboard must then accept whatever curvature(s) you use on your top, hence the traditional solera. I was taught to use a flat board and place a guitar-shaped "mat" built-up to the desired contour between the workboard and the guitar top.)

(In using an outside mold, the order of which of the top or back are glued first doesn't matter much since the sides are not removed from the mold until assembly is complete. During assembly, unlike when working with a workboard, you have access to both "faces" of the sides, those for both top and back.)

With the back already glued on, one option is to position the dowels on the workboard in their correct locations for your guitar outline, flip the guitar body over, force-fitting the sides - re-imposing the longitudinal back arch - into that contour, then glue the top on being carful not to apply too much pressure on the arched back that is against the workboard. You can place some shims at the extremes of upper and lower bouts of the back so that the back arch is not crushed while clamping. The good news is that not a huge amount of pressure is required to clamp the top to the side assembly: you could even use masking tape for much of the clamping. (Gluing the top to the end blocks will require clamps or alternate means of greater pressure.)


Greater vertical force can be generated by the rubber bands by having them bend closer to vertically over the edges of the guitar shape. Smaller diameter (1" or 1-1/4" diameter) dowels will facilitate that, while offering no downside. You shouldn't need the various pieces of wood you are using between the dowels and the guitar sides if the slots in the workboard are suitably located.

[warfrat73]

Well, I'm definitely learning a lot.

I definitely over generalized what I saw people doing that were building in mold, and the mish-mash of techniques isn't doing me any favors.

But, a couple of months ago I didn't even really know how sharpen a plane... so I've made a fair amount of progress.

And I'm finding that I enjoy the work, but that I have to do a better job of listening to my body... when my back starts hurting,, or I starting getting frustrated, I just need to walk away rather than pushing through. That's when I start getting careless, rushing, and forcing things. If I'm honest, that's how I ended up breaking the bubinga sides.

I think I'll stick with it, now that I'm fairly well tooled up. But I also think I'll pony up and buy a mold for the next time around. I've been thinking about my next couple of builds... I just today got another B&S set, won an auction for a well quartered white oak set for $19.

[charles Tauber]

Originally Posted by warfrat73

Well, I'm definitely learning a lot.

I continue to make new mistakes and usually learn something from each one. New tools, new ideas, new methodologies are continually coming to the fore. There is always something new to learn.

In the time that I've been making guitars, there are so many new and different things that have been introduced. Things like, heating blankets for bending sides, "radiused" dishes, mainstream bolt-on necks, including Taylor's NT neck assembly, gauged nut files, gauged nut saws, wide-spread torrefaction of wood, more "artificial" wood alternatives, double sides, double tops, lattice bracing, reverse kerf linings, "fan" frets, electronic tuners, response analysis software for PC/Mac, deflection testing, affordable CNC machinery, affordable drum sanders, laser cutting/etching and so much more, with new stuff coming on a monthly basis.

I definitely over generalized what I saw people doing that were building in mold, and the mish-mash of techniques isn't doing me any favors.

If I had to pick one hurdle that I see novice makers struggle with it would be trying to become "system integrators" on a first build. Many novice makers read a bit here, watch a video there, and mix 'n' match methods and techniques for making guitars. That puts them in a situation where to be successful they need to understand the entirety of the process well enough to see how each piece of the puzzle goes together and then chose which methods or techniques are compatible. They effectively become system integrators for systems they haven't sufficient knowledge to integrate. That often paints them into corners.

Consequently, my best piece of advice is to take any ONE proven method, book or video and do only that method.

But, a couple of months ago I didn't even really know how sharpen a plane... so I've made a fair amount of progress.

Indeed you have. Good for you.

I also think I'll pony up and buy a mold for the next time around.

In keeping with my comments above, if you switch to a mold, understand any one proven method for building with a mold and use that method. (After you have "perfected" that method, branch out, if you like, to try other proven methods, eventually, inventing your own methods.)

[warfrat73]

Originally Posted by charles Tauber

That puts them in a situation where to be successful they need to understand the entirety of the process well enough to see how each piece of the puzzle goes together and then chose which methods or techniques are compatible. They effectively become system integrators for systems they haven't sufficient knowledge to integrate. That often paints them into corners.

I was reflecting earlier today, that just this week I was talking about something very similar with my students... in that case it was over-generalizing genres in writing without understanding the context and situation from which those genres emerged.

It's important to understand why things are done in a particular way in a certain situation, and I'm clearly not there yet. But this is all a learning process still.

Anyway, here's what it looks like with the back glued on and trimmed up... I took a bit of time to cut the slots for the dowels a bit deeper into the board... I had been putting that off because I didn't want to handle the sides too much.

[charles Tauber]

The traditional Spanish construction sequence is an integral neck with slots into which the sides slide. The guitar is assembled face-down on a board (solera), the neck, also face-down, glued to the top, then the (pre-bent) sides attached to the top using small individual blocks, glued on at a time. Linings are then glued to the back-edge of the sides, then the back glued to the side assembly, completing the assembly of the guitar but for fingerboard and bridge. The geometry of the top, neck angle, sides and back are easily maintained throughout the assembly sequence.

One more-modern variation on that is to apply linings to both edges of the sides, then glue the side assembly onto the face-down top, on the workboard. Usually that is arrangement is done with a separate neck.

The method you are using, obviously, is neither of those. The challenge that you will have/are facing is maintaining a constant geometry throughout the assembly. By not gluing the linings to both edges of the sides, it leaves the edge without linings relatively flexible. (Adding linings increases the rigidity of the sides considerably: solid linings increases the rigidity considerably more.) By gluing the "spring-loaded" back first, it will want to flatten out once removed from the dowels (or other outside mold), distorting the sides as it does so.

In using a traditional face-down assembly sequence, the reference surface (datum) is the fixed surface of the workboard/solera. In using an outside mold, the reference surface is the fixed surface of the interior of the mold (as well as the flat faces of the mold.)

In using a traditional face-down assembly sequence, if you remove the assembly part way through the assembly, it is easy to re-establish the reference data simply by reclamping it to the board/solera. In using an outside mold, if components are removed from the mold part way through the assembly sequence, again, it is easy to re-establish the reference data, just by putting it back into the rigid mold.

In the sequence you are using, you don't really have a fixed reference datum. The parts move around during your assembly sequence.

As I previously mentioned, it is important than the "plane" of the top be maintained when it is glued to the side assembly. The geometry is more complex if the top is arched - and whether or not the curvature is cylindrical, spherical or something else.

If, for discussion purposes, we assume that your top is intended to be dead flat (i.e. planar), then the edge (future gluing surface) of the bent side assembly must be similarly planar. In other words, if you laid a flat board (plywood/MDF) on the sides where the top will be glued, the sides should touch the board around the entire perimeter of the sides. If the sides are distorted inward or outward, the gluing surface of the sides at the top will have a gap between it and the reference surface (i.e. board). As the un-restrained back tries to flatten out, it will splay the end blocks outward, causing the waist area of the sides at the top gluing surface to sit high. If you press the end blocks inward too far while attempting to recreate the origional longitudinal arch in the back, the opposite will happen and the waist will sit low. If you then try to glue a top to the distorted sides, you lock-in that distortion into the top. Establishing a playable neck angle becomes a challenge.

All of that becomes more difficult as one introduces an intended arch into the guitar top. The difficulty is in figuring out how far to press the end blocks in to obtain the desired geometry of the gluing surface for the top.

Since Bruce regularly builds without molds, perhaps he has some ideas/expertise to lend on how to establish and stabilize the geometry using your current assembly sequence.