Building a 13 Course Lute, Start to Finish, 4: Gluing on the Neck

Hi, and welcome back to the series!

In this instalment, I want to detail how I re-fit and glued the veneered neck to the body of this 13 course lute. As I explained at the tail end of the last episode, hide glue contracts as it dries and hardens, which can be a difficulty in working with it, but also a benefit in certain situations. We'll see those two properties of hide glue demonstrated in this episode.

By the way, to clarify, when I talk about 'hide glue' on this blog, I am always referring to hot hide glue, the stuff that's sold in granular form and must be soaked and then heated in a water bath to use. It is the only glue that I use in building my instruments.

The granules

The heated glue

As I mentioned at the end of the last episode, I set this neck aside for a week after gluing on the veneer, because it takes that long for the glue to dry completely and for the neck to stabilize. It's a big surface area--the biggest, or at least the widest, glued surface on this entire lute--and while it dries, the hide glue tightens like a fist. The whole area covered by the veneer shrinks, and pulls the edges of the neck downward; the result is that the top of the neck, which was dead-flat when I first fitted and shaped it, is now humped pretty significantly both across and along its surface, about 1mm in both directions. (It doesn't sound like much, but in this situation, that's pretty significant.) I'll need to flatten it before I can re-fit the neck to the body, and then eventually glue it on. I'll also need to flatten and re-fit the neck-joint surface, which I sized with weak hide glue during the veneering process. (Its profile is actually a little concave right now.) The way I flatten the top surface is with my trusty low-angle block plane, planing from the outer edges in toward the middle of the neck. I do some of the trimming with the neck off the body, but most of it I do with the neck fitted up, just because it's a lot easier for me to handle at the bench.

As you saw in earlier posts, this is how I check the angle of the neck in relation to the body--with a long straightedge held against the top surface of the neck, viewed in relation to a thread stretched across the body at the bridge position. This is why I need the top surface of the neck to be flat--so that my straightedge will register cleanly against it.

I also check the alignment of the neck with my centreline thread. 

The alignment looks pretty good. Remember, on this 13 course lute--and in fact most wider-necked lutes--the centreline of the body and that of the neck do not coincide (the neck is usually 'tipped' a little toward the bass side.) In this photo you can see the pencilled neck centreline, but the body centreline is covered by the thread that I'm stretching up from the bottom of the body.

Looks good down at the body-neck joint too. You may notice in this picture that I haven't flattened the entire neck surface--I've really only paid close attention to flattening the outside edges, which is where I hold my straight edge to check the neck angle. The upper neck surface actually remains a little humped-up in cross section (and as long as the alignment and neck angle are good, that won't bother me a bit.)

Here my neck is fitted, and I'm getting ready to glue. Since the pencil mark I've been using to align things is going to be obscured by glue squeeze-out, I need a better, clearer way of marking neck alignment when I glue up. I put down a strip of 1/2" masking tape across the joint...

And then cut the tape in two with a knife, right along the joint. Then I can unscrew the neck from the body, and get ready to glue the neck in place.

Here's what I'm looking at just prior to gluing. I'll warm both surfaces with a hair dryer before brushing glue on both surfaces.

Here's a wider shot of the gluing situation, courtesy of my A/V assistant, Carl, whom you met in the previous instalment. I'm about to do a rehearsal, a dry run. When I go for real (in about twenty seconds from now), I'll warm the surfaces, brush glue on both surfaces, rub the joint slightly to get good contact, make sure alignment with the tape is correct, and then twist the screw home.

The immediate aftermath, showing the tape alignment and glue squeeze-out. Rather than clean up the excess glue, though, I will actually add to it, by painting more full strength glue along this glue line...

And on the backside of the joint as well. Here is where we see the beneficial aspect of hide glue's tendency to shrink as it dries--the drying glue will contract and pull the two edges of the joint together, providing external clamping pressure (along with the internal pressure applied by the screw.) I will actually paint more hot glue on the outside of the joint a couple of times over the next few minutes, to create more concentric layers of clamping pressure.

I don't hang the lute to dry, but prop it up gently instead.

Next morning: here's my result. The alignment looks good, and the joint looks tight (though again, you can see where the middle of the neck surface is a bit humped up in relation to the top block.)

I usually use a piece of paper towel to clean up excess dried hide glue. I wet the glue first, then lay down paper on it, then re-wet the paper as need arises over the next 15 minutes or so. 

By then, the glue is soft enough for me to clear away with a sharpened spruce stick.

Here's my joint: the alignment of veneer and ribs looks fine. Not perfect--such a joint only rarely comes out perfectly, and there is generally always some filing and rectifying of either the veneer or the ribs to be done. But this looks good. 

So for the time being, I'll hang this one with his fellows (an 8 course on the left, 7 course on the right, both also with veneered necks). By the way, at this point I will not re-check the alignment of the neck, either with my centreline string or my straightedge and thread--there will be plenty of opportunities for me to check those things a little farther down the road. For now, I've got bigger fish to fry...

Or should I say fish bellies? In our next episode of 'The Tedium and the Triumph,' I'll let you know how I go about thicknessing these flounders--and preparing them for carving their roses.

Before I sign off, I'd like to thank everyone who got in touch with me after the last blog post, where I expressed some misgivings about my (rather exhaustive) sharing of my working techniques in building a 13 course lute. Three people in particular helped to clarify my thinking, and I hope they don't mind me mentioning them here--Grant Tomlinson, Bill Good, and Bob Eby. Just share, they said, and don't worry about it. So that's what I'll do. Thanks.

Building a 13 Course Lute, Start to Finish, 3: Veneering the Neck

Hi friends, today I want to document veneering the neck with a single piece of ebony.

If you've been tuning in to this series, you'll know that my rationale in these posts is to present a photo and one-or-two sentence description of each discrete operation in building a 13 course lute. It's not my intention to present a how-to blog, though of course there's much information to be found for those who want it.

I have to confess that, after making the first two posts in the series, I felt a little pang of something--maybe of guilt, maybe of jealousy--with which I've had to reconcile before continuing the series.

Guilt first: on one hand I'm happy to talk about my working procedures (and nobody's forcing me to do it, after all), but I've had a nagging feeling, as I've been doing it, that they are not quite mine to share. After all, I learned them from my great teacher, Grant Tomlinson; and he learned them from his own great teacher, Stephen Gottlieb. Am I not appropriating their ideas, and presenting them as my own?--And yet these procedures are mine; I've earned them with my hard work, and though they have their source in those great makers, for better or worse I've taken them and made them my own. And so, I share them humbly, and hope in so doing to show respect and pay tribute not only to Grant Tomlinson, but to all the teachers, woodworkers and luthiers who have guided me (and still do guide me) on my journey in craft.

Now, jealousy. As I write these posts, I sometimes wonder: am I not sharing too much? Am I not giving away the farm, by talking in so much detail about how I do my work? It's a good question; many makers have derived income by packaging and selling such information. Well, maybe I will too, at some point; maybe these blog posts will eventually form the basis of a best-seller on how to build baroque lutes, and my sweetheart and I will retire on the royalties to our private island in the Caribbean. Indeed!--For now, though, I've resolved not to feel jealous about sharing what I know, and what I've learned. For one thing, there is plenty of information that I am not giving away in these posts, information that can really only be imparted through personal contact between a teacher and student, side-by-side at the bench. For another, if what I offer here helps someone to build a better baroque lute, and in consequence there are more excellent baroque lutes being played, and more people listening to great players on excellent baroque lutes, then I'll count that a good thing, not a bad one. So by all means, dear reader: take whatever is useful to you, use it to build great baroque lutes, and please, pass it on.

To begin.

I've carved the neck, and allowed for the thickness of the veneer.

This is my neck veneering jig (and my cup of coffee.)

Another view.

And yet another: this view shows the length of thick cotton skate lace that I use to tie the veneer down to the neck. I use skate lace because 1) it is very strong woven cotton, and 2) it is wide and flat.

The neck must sit up from the jig at a particular angle so that the veneer will tie down closely at the edges. I've worked out this angle (and made these wedges) through trial and error.

The nut end of the neck must sit up higher than the bottom (joint) end.  

Because the neck has a slightly asymmetrical shape, it must also sit slightly askew the centreline of the jig. 

A dry run with the skate lace allows me to check whether I've got the angles right, and the veneer will tie down tightly all along both edges of the neck.

It also allows me to rehearse the best way to tie the lace around the bottom end of the neck. 

I mark out the veneer, leaving a couple of millimetres extra in each dimension.

Then I cut it out and run it through the thickness sander.

I scrape the outside surface free of sanding marks, then run it through the sander one more time (with the outside surface face-down) to take the veneer to its final thickness.

My neck, my veneer, my jig, my glue, my bending iron, are all ready to go. I'll bend the veneer and glue it, working at a fairly quick but careful pace.

I've heated a saucepan of water, which I brush on the outside of the veneer. The veneer begins to curl immediately.

I also heat the underside of the veneer on the hot plate, which helps to curl the veneer even more. (The only use I have for the bending iron is to do some fine shaping on the outer edges of the veneer, near the nut end of the neck.)

I locate the veneer carefully and hold it in place while drilling a small-diameter hole through it. 

I can then locate the end of the veneer securely with a push-pin.

I drill another hole about halfway up the neck for a second location pin.

Working quickly, I heat the neck surface and the inside surface of the veneer with a hair dryer, then brush hot glue on the neck core.

Then I brush hot glue on the inside of the veneer.

I get the veneer in place quickly, and locate it with my pins.

Then I start tying it down tightly with the skate lace.

So far, so good. I can remove the location pins...

And start applying heat and pressure with the iron. You can see I'm getting some significant glue squeeze-out through the hole for the location  pin, halfway up the neck; I also check for squeeze-out along the length of the neck, on each side.

I continue tying off until the entire veneer is tight.

I also keep ironing until I'm quite satisfied that the veneer is glued closely to the neck core, and that there are no gaps or air bubbles.

The fit looks pretty good from the nut end...

... and from the bottom end too. I clean up the glue squeeze-out with a brush, and then give the surface of the joint a coat of glue size.

At this time, I would like to introduce my audio-visual aide, whose name (for some reason) is Carl. Without his sturdy assistance, none of the actions shots of me working would be possible. Thanks Carl!

Next morning: the glue is dry, and I can remove the veneered neck from the jig. Here I am beginning to carefully saw away the excess veneer at the joint end of the neck.

I use my low-angle block plane (with the sole well-waxed) to plane the veneer almost flush with the surface of the joint. I use the low-angle plane to bring all the other veneer edges flush to the neck core as well.

Top view of the veneered neck: I think I got a good result.

The back side looks good too. No big lumps or bumps, no air pockets; everything looks solid.

Now, I will set the neck aside for at least one week before re-fitting and gluing it to the body. This is because hot hide glue, when used over a large surface such as this, will take a long time to dry thoroughly. While it dries over a number of days, it will continuously contract, mainly across the grain, but also along the grain as well. (This property of hide glue to contract as it dries is one of the main difficulties of working with it, but also, in certain circumstances, one of its great benefits.) As it contracts, it exerts a great deal of force on the woods on each side of the joint, and ends up significantly distorting the shape of the neck. The upper surface of the neck was dead-flat when I began shaping it; it's no longer anywhere near flat, either in cross-section or long section. The same is true for the neck-joint surface. By putting the neck aside for a week, I hope to allow the woods and the glue enough time to reach an equilibrium before fitting and gluing the crucial neck joint.

And so the blog will take a break as well. Happy lute making--and happy lute playing--and I will talk to you again soon.