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At last winter has arrived, and the humidity has dropped like a rock, so it's time to turn this pile of pieces into a box I haven't done much yet, but did finalize the top thickness and cut out the soundhole. I had it at .110" all over before, and planed the perimeter down to around .095".

Scrape it all smooth, and re-shellac. Then cut the rest of the way through for the soundhole, and round over the edge and shellac that too. Also finished cutting out the cutaway.

I may have to wait a couple more days before gluing braces, because today and tomorrow are going to be extreme cold, and therefore a little too dry. But that's ok, because there's still a bit more prep work to do. Radius the brace blanks, make the bridge plate, tail block, cutaway corner block, and bend the sides. But hopefully I'll have an open-back box within the week. Then I can get to the fun part, learning how to make a bevel and get it to blend into the binding elegantly...

Time to get the neck glued to the soundboard (or is it the soundboard glued to the neck?)

First, saw straight across the soundboard at the 12th fret location. This is a deceptively important task, because it determines the location of the soundhole relative to the fret positions, which needs to be pretty accurate for the planned fingerboard end treatment to work.

Second, saw a 45 degree angle toward the cutaway. Then trace the soundboard end onto the neck. It's important to get it clamped up with the neck pointed straight along the centerline here. I use a straightedge held along either side of the neck, and measure the distance to the centerline at the bridge location to make sure it's equal on both sides.

Then score down the cutaway side.

Chisel/scrape the cutaway glue area, and route the soundboard ledge. I used to chisel the soundboard ledge, until I screwed it up one time. Router gets the depth more consistent. But this time, I should have chiseled it, because then I would have realized that the soundboard upper bout is slightly thinner in the center (related to starting with a tapered house siding board), which left a slight dip if pressed down. But 3 strips of paper (each wider than the one beneath it) is all it took to build it up just right.

If cut correctly, pushing the soundboard into that 45 degree corner should get the neck pointed directly along the centerline, so when the glue goes on, that's all I have to do. Then it can either be clamped with a caul, or pressed down against the bench. I went with the latter. Stick a cam clamp on the heel, prop the neck up with random stuff, and stand on the headblock extension part for a few minutes until the glue starts to dry. Then switch to a weight.

I also got the upper transverse brace glued (which is also butt jointed to the endgrain of the neck... which is surprisingly strong if you pre-treat the endgrain with hide glue).

But that was as far as I made it before the extreme cold set in and the humidity went too low for further bracing. But I can still do the fingerboard end.

First step, use the existing position pin holes to stick it on the neck, and trace the soundhole edge onto the underside of the fingerboard. Position the paper pattern relative to that mark, and trace around the paper to get the curvy bit.

Then go at it with a jeweler's saw.

Clean up with a file and sandpaper, and it's a perfect fit

It's back to being merely freezing cold now, so hopefully I'll be able to glue the rest of the braces soon. Still a bit too dry at the moment.

It's interesting to see the differences in how you build versus my own methods. Thanks for taking the time to show us Dennis.

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Steve Smith
"Music is what feelings sound like"

Bracing time!

Got all the blanks dimensioned and radiused, and little bits of tape on the soundboard to mark where they go.

Then glue them on. I should probably get a radius dish and go-bar deck at some point... it gets a bit tedious doing them one by one.

And the bridge plate. I made it from one of the back offcuts. Underneath is a pine scrap that I scraped concave for this purpose. I should probably use a caul on top as well, but just sticking a bunch of clamps on it seems to work fine.

Then carve those braces while it's easy without the X in the way.

And add the X.

I decided the planned 1/2" height for the X brace was way too much for a guitar this size, so I hacked it down to 3/8". 7/16" might be a bit more wise, but honestly it still feels too stiff right now. Pretty sure I'll be chopping on everything below the X intersection some more when I get to the open-back box stage.

Next up: side bending.

I like to carve lol the other braces before I glue in the x too.

This thing is going to have a ton of mojo. I hope I get to see it in person at one of our gatherings.

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Bryan Bear PMoMC

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

I chickened out on my brace carving and glued a 1/16" thick strip on one of the upper X legs to add just a bit more stiffness. It's probably not necessary, but upper bout stiffness doesn't really hurt tone, and better safe than sorry when it comes to the vulnerable soundhole area.

That taken care of, it's box building time! Before bending the sides, I might as well nibble some binding strips from the excess width. My stock of binding is growing faster than it's shrinking.

Bending went relatively easily. This oak likes having a wet paper towel on the pipe.

I made the cutaway block from one of the soundboard scraps (from the thick side of the tapered house siding board). The tail block is from the maple tree that fell in the back yard about 6 months ago, that I mentioned back on page 1. Hopefully it's dry enough by now. 1 year per inch of thickness is the rule, so being a little over 1/2" it should be pretty much good.

Then comes the longest day of every guitar build... as soon as the sides are touched up on the hot pipe, it's a race against time before they decide to warp. I use the bending pattern to mark the cutting locations on each of the pieces, a square to extend them across the width, saw close to the lines, and drag on sandpaper to finalize (and to create the cutaway miter). Glue it all together and it's ready to go onto the soundboard.

I still haven't found a good way to clamp the cutaway side to the headblock, so I just hold it by hand for 10-20 minutes. Then get a few dentellones glued here and there to keep the sides from moving. Probably would be lunch time for most people at this point, but it takes me all day, so time for bed before gluing the remaining dentellones the next morning.

And it's all nice and pretty.

Still need back linings to officially declare that I've reached the open back box stage. I had to get more lining clamps. I normally use full height side braces and glue short strips between them, so I can use the same few clamps repeatedly. I left these sides thicker usual to increase the weight a bit for theoretical bass boost, and oak seems pretty split resistant, so I decided to skip the braces. And that means using continuous lining strips, which are better to glue all at once.

I think that's good progress for one day. I see you made the dentellones size from small to large and back to small on the bass-side lower bout. Are you going to do an armrest on this one?

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Steve Smith
"Music is what feelings sound like"

I am amazed at the inlay in this project. I can barely inlay veneer purfling strips into a round rosette hole to get a ring rosette and round aluminum rod into the fretboard for side marker dots. I haven't yet even inlaid round marker dots into the top of my fretboards yet.

And here you are inlaying sticks and twigs with weird complicated shapes, lumps, bumps, and bark into a rosette.. And all these little bits entwine and overlap... And if that's not enough... You make the little bird from scratch out of sea shells and rocks...

On the top bracing.... You may find that it's hard to get much more out of shaving the top braces with a relatively thick top for a small guitar. I think I end up around 0.060" thick or so around the lower bout perimeter and generally no more than 0.100" in the middle/upper bout on small guitars like this... But it depends on the sound you are after.

This is a fun little build.

Yep. Not a very big one... just about 1/2" reduction in soundboard lower bout width. It's my first time making a bevel. The only part I'm a bit worried about is where it meets the purfling. I think I'll need to add a little filler strip outside the purfling before I carve the bevel, and then try not to sand through to it when rounding over the bevel veneer. I'll make it the same material as the veneer just incase, but being maple, the glue line will show if I expose it.


Wow, that's thin indeed at the perimeter! This is about .110" in the center, so should be comparable to .100" spruce. Perimeter is around .095", so I may thin that a bit further. It's sounding very tight at the moment. Definitely need to carve the lower bout braces some more. My tonal goal is "not boxy".

Glad you're doing a bevel. I don't think it will take a very large bevel to make a big difference in comfort. I round over my bindings more than a lot of people do and with just that small change I can feel the difference while I'm playing. I'm looking forward to seeing how you do your bevel.

_________________
Steve Smith
"Music is what feelings sound like"

Yeah, it seems especially beneficial for small guitars, where my wrist rests on the edge at almost exactly 45 degrees. The bevel should be just right to spread out the force.

Continuing with the build, I decided to pre-bend the linings on the hot pipe before gluing, and managed to get them in with no complete breaks. Turns out the cheap binder clips work even better than my old spring clamps, except in the tight curves where they're a little wide.

Then plane the linings down about flush with the rim, and drag on coarse sandpaper to level it off.

But that resulted in the headblock foot being not angled quite right, so then I taped two sheets of sandpaper together to make a longer surface that can sand the entire length of the box at once, and create a more accurate cylindrical radius. That worked better.

The back has been getting increasingly worse with its S curve as the humidity drops. Fortunately I had it thin enough already that it squashes flat under the plane for final thicknessing, but it was still very stiff across the grain at my original target .090". The bad half didn't like being flexed flat, much less convex. So I decided to thin it to around .080" and use 4 back braces instead of 3. Its tap tone is really bad, so I want to make sure it's good and rigid so it doesn't participate much in the tone. I'm tempted to scrap it and use one of the 4 small Honduran rosewood backs I have, which are actually a very good color match for this oak, but much more stable and better sounding. But then the guitar would lose its local material purity... So for now, I'm sticking with the oak.

I decided to make the braces out of oak as well, to add some weight, and because I have these sticks that I don't know what else to do with. This dozuki saw is awesome. I went through 60 square inches in less than an hour, whereas most saws would have taken at least twice as long.

Then saw at an angle to correct the runout while creating the individual brace blanks. Plane the radius, carve the ends down as low as I want them, and notch the linings so they fit perfectly level with the rim.

The tape bits are there so I can press the back down onto the braces and pull them up in their exact right positions. Then stick more tape around the ends to mark their locations.

And glue them down one by one, peeling the tape markers off as I go.

And the braced back fits onto the box perfectly flush Then I can trace around with a pencil, and trim the excess close to the line so there's minimal overhang.

And then carve the back braces, which was rather difficult with such a hard wood. Mostly went at it with a block plane, and then a bit of chisel work to round them over. Then clean up the dry glue squeeze-out with water.

But I think I kept them wet for too long and the water started to soak into the glue underneath the braces, because a couple of the brace ends peeled up when I gave them their strength test, and thus had to be glued back down again (fortunately easy to do with hide glue, since it sticks to old residue). I'll have to be more careful in the future, and chisel off the last bit of glue at the base of the braces rather than waiting for the water to soften it.

Next is to add the center reinforcement and do the label painting. Unfortunately adding the 4th brace means that the second one cuts across the soundhole area, so there's not as nice of an open space to paint eggs in the nest. One more reason to consider switching to the rosewood back...

I know its a bit late now and all.... But Oak backs are very easy to flatten or shape a bit with a common clothes iron.

I have a similar nicely quartersawn oak back that wouldn't lay flat for love nor money... Ironed it out with the wife's clothes iron on a piece of plywood.. Once it gets hot - you can feel it relax and flop.

I then laid it under a stack of plywood to keep it flat... Viola. Almost a year later and still good and flat.

You could probably pre-dish an oak back using the same technique.... Or even just heat it up real good and lay it on top of your braces.

It was a LOT easier to flatten than rosewood... Which always wanted to fight me.

Is that a year later with or without braces? And does it even stay flat if you leave it sitting out (both sides exposed to air) in variable humidity? I've never actually tried ironing guitar woods, so I'm not sure if it permanently rearranges the fibers into a more stable configuration or just temporarily solves the problem.

Continuing work on this oak back, I made some center reinforcements from the offcuts, and did the label painting:

Also carved on the braces some more.

The fingers and tone bar are down to 1/4" tall now, and everything tapers more near the perimeter. The tap tone sounds good both open box and with the back spool clamped on, but I think the frequencies are still too high. I'm not sure what I'm going to do yet. Carve more, thin the perimeter more, a little of both, or leave it alone for now and work through the soundhole later if it seems like it needs it?

While pondering that, I decided to make the bridge. Start by marking the bridge pin and saddle end locations.

Drill them through, and construct a saddle slotting jig out of cam clamps and whatever reasonably straight thing happens to be lying around (my fret leveling beam in this case). I route it using a 1/16" bit, using that 1/16" thick ruler as a shim on every other pass to make a 1/8" slot.

Then taper the thickness of the bridge from the back side, so the saddle slot and pin holes get tilted back a few degrees.

While scraping smooth after the plane, I also give it some radius to minimize the amount of sanding that will need to be done to fit it to the soundboard.

Then mark the pattern on the underside, and make a bunch of cuts with a straight saw to rough out the shape, and a bit of jeweler's saw for the inside curves. Then use a chisel to refine the shape. Around the endgrain I nibble at it from the back side like this:

And side grain can be carved with it held on its edge. I used to have a vise, but I gave it to my brother because it was always quicker to make one out of cam clamps

Then refine the shape with coarse files followed by needle files and sandpaper. Carve the top side with chisel and scraper, a bit of file/sandpaper work to round over the edge, and it's done

The relief carving is pretty subtle, but shows nicely in side lighting like that.

I'm struggling to resist the urge to shellac it while it's all pristine, so I can put water on it when gluing to equalize moisture expansion. This is flatsawn persimmon, so it's probably going to curve like crazy as soon as the glue touches it.

Wow, Very nice!

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Blog on Making Stuff: http://www.McGlynnOnMaking.com

On my oak back.... Over a year good and flat.... It came to me curved like a potato chip and nothing I did would flatten it till I ironed it out... I have had it about 10 years and it's been a curved mess for a long time before that.

looks like you are making some good progress on that bridge. That's a very graceful shape.

Ok then, I'll try ironing another problem back set that I have and see how it does

I decided to carve on the braces a little more (mainly the ends). It's getting pretty plush when pressing on it from the outside, so I'm a bit wary of going further. But the frequencies only dropped by a couple Hz compared to the previous bracing photo.

And then glued the back on:

The tap frequencies were 113Hz for the air and 221Hz for the top, both of which are rather high, so I did some perimeter thinning. Now 109Hz and 215Hz. Still high. Adding the bridge+pins+saddle will probably drop it a bit more, but it may need more brace shaving as well. But that can be done after it's strung up and I can measure bridge rotation under tension, so I'll leave it alone for now.

Next up: binding and bevel.

Do you find your tap frequencies stay pretty stable from back screwed on with clamps to finished instrument? As you say - you would expect a little drop when the bridge is glued on, but I would expect some increase from removing the side weight from the clamps...

How do you measure the tap frequencies? I have the peterson tuner app on my phone, would that do it? Where can I learn more about this whole tap tuning thing?

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Blog on Making Stuff: http://www.McGlynnOnMaking.com

Record in Audacity. Hold the guitar up gently by the neck and tap 3 times at the bridge location. Then go to the Analyze menu and click Plot Spectrum. Set axis to "Log frequency", and (assuming you recorded at 44100Hz) window size to 16384, and you should get a nice view of the main 3 peaks. Mouse over and it will tell you their exact frequencies.

Gore/Gilet design book is the place to learn more.


Yeah, the clamps make the frequencies lower. It usually correlates somewhat, like the top/back maintain their note interval or close to it. Here's the tap with the back spool clamped on (about half the number of clamps that I use for the actual glue-up). Peaks are 111Hz (A2), 195Hz (G3), 254Hz (B3).

And here it is after gluing and removing the clamps. Peaks 113Hz (A2), 221Hz (A3), 288Hz (D4). Unusually small change in the air frequency. The back's peak looks insignificant now because the soundboard and air are so much louder without the clamps damping the soundboard edge. But as said in earlier posts, non-live back is what I'm going for on this one.

Here it is after perimeter thinning. Peaks 109Hz (A2), 215Hz (A3), 287Hz (D4).


And for comparison, here's Galaxy, which sounds great. Peaks are 98Hz (G2), 175Hz (F3), 223Hz (A3). The live back helps to repel the soundboard frequency lower.

I really do need to get Audacity cranked back up again. It's a slick program. And I am just nerdy like that... I need to "tune up" the dread I finished at Christmas...

That's what happens when you are out of building for 5 years....

I'm not quite finished with the binding/bevel yet, but I have a couple posts worth of pictures so I might as well start writing while I wait for glue to dry.

The binding/purfling ledges were cut with gramil and chisel as usual, plus a bit of smoothing with a needle file, and sandpaper wrapped around a cylinder to get the waist/cutaway.

Then comes the fun part. Start carving the bevel with a chisel:

When I get reasonably close to where I want to be, switch to a coarse rasp, followed by a file.

Being that this is approximately the surface that the veneer will eventually glue to, I can now make a paper pattern for it. Hold the paper against the bevel so it wraps around, and rub over the edges to make a crease. Better to do this with dirty fingers so it highlights the line Note the clamp behind the guitar, which is holding a block of wood for me to push the guitar up against. I needed both hands and a foot to keep the paper from slipping and sliding around during the creasing process.

Then begin carving the purfling ledge. First step is to remove the beveled soundboard wood, right to where it transitions to the soundboard surface.

But that edge is where the veneer will meet the soundboard plane, so I need to carve another 1/16" or so inward for the purfling. Easy enough to eyeball it with chisel/needle file. Here you can see the widened ledge, as well as the interesting geometry where the bevel intersects the main binding/purfling channels.

Then bend all the bindings and purflings, including an extra purfling-height maple strip to go around the outside of the bevel purfling. This strip replaces the beveled soundboard wood that I carved away in Bevel2.jpg. If I play my cards right, it will be completely covered by the veneer. But good to have it match, just incase I cut through to it anywhere.

Then glue the purfling and the filler. The purfling strip is only glued in the bevel area, and still loose up toward the shoulder. The filler strip needs to be bent accurately, because the tape can't put a lot of side pressure on it at this angle.

Once that's dry...

...carve the ends of the filler strip to merge into the binding channel, and the bindings can finally be installed:

Then carve the binding ends and the filler strip to merge into the bevel, and level the binding/purfling to the soundboard surface.

I decided to try an experiment at this stage. The tap tone still sounded weak, as it normally does before bindings are glued. But this should be structurally strong already, so the only difference is the gaps between the bevel dentellones. So I stuck bits of tape over them... and the tap tone did indeed recover! But what really makes it interesting is that peeling up a single strip of tape significantly reduces the duration of the tap tone.

So I don't think I'll be doing any of those Ryan style bevels with soundports in them.

Time to finalize the bevel glue surface. Using a file, work it until the bevel intersects the soundboard plane precisely at the purfling. Right side is done, left side still has a sliver of maple visible. Getting the light at the right angle is a big help here.

And give it a light scraping to remove the file marks. Here's a closeup of the tail end of the bevel, where you can see all the pieces intersecting.

Now to make the veneer... which is actually sitting on the guitar in that previous shot But before that, I cut out the paper pattern I made earlier, and traced around it on the same 1/4" thick birdseye maple board from which I cut the binding strips. Cut it out with a coping saw, and then slice in half with dozuki, because it doesn't hurt to have a spare incase of bending trouble.

Then bent it with a wet paper towel on the pipe... and it cupped very badly. So I did indeed end up using the spare, which I somehow managed to bend dry without scorching. It still cupped a little bit in the areas where I was bending at 45 degrees to the grain direction, but minimal enough that a bit of scraping and plenty of tape should get a tight fit.

One final thing to do before gluing is to round over the edge on the veneer, so it won't cut the tape when pulled tight. I used a knife, working slowly and carefully so as not to chop myself.

Another trick I used when gluing it on is putting water on the outer surface to counter the expansion from water in the glue. Also makes it a bit more flexible so it will conform to the surface underneath. But this maple is very forgiving of bend accuracy anyway. I'd hate to do a purpleheart bevel, because that wood is insanely stiff and has to be bent perfectly.

Here it is in its current state, all taped up.

As far as I know, everything went according to plan. All that remains is to level it to the soundboard/sides, and round it over along with the rest of the binding.

Thanks for going through the process on that... It sounds tricky to me...

thanks for sharing that. Looks like some fussy work to say the least. How did you lay out the stepped edge that you had to cut after shaping the bevel? Was that just eyeballed?

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Blog on Making Stuff: http://www.McGlynnOnMaking.com

Excellent series of bevel pictures. Thanks

Ed