Friday, January 25, 2002

Mandolin #1: Assembly

At this point, we've done a lot of prep and are ready to start putting things together.

Gluing the Top
It was now time to glue the top to the rim. I had seen people using special spool clamps from luthiery supply shops and liked the idea but was hesitant to fork over the money. Thus, I set out to build my own clamps. Returning from the hardware store with about 50 pounds of washers, bolts, and wingnuts (actually I think the guys at the hardware store thought I was the wingnut), I cut some square pads out of cork and assembled my clamps. In the end, I probably spent about 3/4 of the amount it would have cost me to buy them pre-made, and I ended up with clamps that are about 3/4 as good. That being said, if I had just copied the ones in the catalogs and used dowels and felt pads instead of my fat (and expensive) washers and cork, I probably could have saved some money and more closely matched the usability of the catalog clamps. I forget now why I didn't go that route but I'm sure it had something to do with not wanting to be looked at like a wingnut by the guys at the hardware store again.

In any case, I told myself that my clamp design was better anyway because it allowed the washers to tilt as they were tightened to make better contact with the angled surface of the top. The downside was the occasional projectile clamp as the tightening of the wingnut (talking about the metal one here) caused the clamp to slip off the side. As I tightened I watched for glue squeezing out to make sure I was getting good contact between the top and body.

Another handy tip from the MacRostie video was to draw on the maple rim (but not kerfing) with a colored pencil before gluing. The wax from the pencil prevents the top from gluing securely to the rim. Remember that the main gluing surface is the kerfing and we're just going to route away that part of the top to make a ledge for the binding anyway.

Gluing on the top 2 Gluing on the top 

 Top gluing clamps Top gluing clamps 2

Self Doubt (required step)
It's about this point that I realized that I had no business building this mandolin. Question: If the neck on the mandolin I play was misaligned, would I reset it? No. Would I be able to tell if it was misaligned in the first place? No. Okay, let's say it's aligned. Is the neck angle correct? Wha?

In an odd way, this realization actually gave me a boost of confidence. Confidence that the specifics of neck alignment and angle were not really that important? Confidence that my "inner luthier" would guide me? Not exactly. More like confidence in knowing that most people who are doing this at least have some experience doing instrument repair or have someone looking over their shoulder and that without the benefit of either, all I could do was give it a shot and hope for the best but expect less. There are so many factors that are discussed regularly among musicians and luthiers that affect the sound, appearance, and playability of an instrument. Then and there, I decided that while I would love to end up with a great sounding, looking, and playing mandolin, I had to remember that this was only #1.

Fitting the Dovetail
Buoyed by my new lower expectations, I set about following the MacRostie video instructions for aligning the neck. With the neck pressed firmly the the dovetail joint, a template was rubber banded to the neck. The template projected a center line down through the body. In hindsight, cardboard may not have been the most accurate of materials but I was running low on plastic. Also, in the course of sanding, I had managed to remove my center marks from the top and rim. The best I could do was look for the seam in the spruce top and project it down onto the bottom of the rim. By filing one cheek of the outside of the dovetail slot the alignment was adjusted until the immutable cardboard, rubber band, and felt-tip pen line system (same one they use to land the space shuttle incidently) pointed to the approximation of the centerline. Once aligned, symmetrical filing on both cheeks and some trimming of the maple rim where it extends into the dovetail combined with repeated testing allowed the neck to slide down to the bottom of the dovetail (it's still on it's way down in the picture). Once in the angle and height was set, the 15th fret cross-piece was fitted by trimming back the top wood until the cross-piece could be dropped over the top of the neck dovetail and slipped snugly in next to the top. The first chunk of the top was removed with the dovetail saw and the fit was fine tuned by scoring a line with an xacto and chiseling followed by filing.

With the neck in the body and the whole thing clamped to the table to preserve the neck angle, a dovetail saw was used to trim away the excess neck heel poking out the bottom of the slot. Note the block under the tail to take the weight of the body off the neck. After a rough cut the heel was then leveled to the neck block using a sanding stick with 60 grit paper. Drawing on the neck block with a pencil and then watching for the pencil marks to be sanded away seemed to be a good way to know when it was level.

Oh, and speaking of mission critical precision, check out my coping saw cut on the scroll block in the rim. It occurred to me a little late how crucial it was that the saw blade be perfectly perpendicular to the scroll if I wanted the scroll to come out the same on both sides. Oh well, we'll be seeing the consequences of this soon...

Aligning the neck Aligning the neck 2

Fitting the dovetail 2 Fitting the dovetail

Trimming the neck heel Leveling the neck heel     

The Label
The next big step was gluing on the back. Having the neck in the body, if only temporarily, made it look a little like a mandolin but in reality it looked more like a tennis racket. Once the back was glued on, I'd have a totally finished part of the mandolin (the inside!) that couldn't be changed. Then again, as big of a step as it was, it would take about 10 minutes to do. But before I could do it, I needed to take care of one thing: the label (I just looked up how to use a colon; Nice huh? (Also saw some stuff on semi-colons (Obviously I use parenthesis more like a programmer than a writer.).).).

I had always been thinking that I would inlay "Coydog" on the headstock of my mandolin. Coydog is just a word/concept that I came across when doing some online research into different dog breeds and mixes to get an idea of what combination of breeds my dog Jackson could be. People comment that she looks a lot like a coyote and her size, general body shape, and coloration support the observation. While I doubt that she is part coyote, my research took me to several sites discussing coyote/domestic dog mixes called "coydogs." In general, I don't support the concept of purposely breeding coyotes and domestic dogs nor do I think a coyote/domestic dog mix would be an advisable pet for the large majority of people. That being said, I found the concept and the simple word that described it to be interesting in that it represented what would happen if one were to careful engineer something to remove the primal and raw characteristics and to optimize what remained and then reintroduced those characteristics back in on top of the result. I liked the concept of having something that was carefully designed based on experience and technology but that somehow retained the innate properties that made it desirable in the first place. I thought it would be a good name for a company or project sometime down the road and thus registered the name and created the Web site you're reading this on. As it relates to instrument building, there is endless technology and improved techniques in the form of carbon fiber truss rods and specialized jigs and tools that allow us to optimize the aesthetic and acoustical design of the product, but the end goal is to create an instrument that additionally has a certain organic quality that is very difficult to quantify.

With this in mind, I set out to create a label to affix to the back before it was glued on. Here's another example of overthinking something. I wonder if this ink/paper will last 400 years? How will future generations of instrument experts reflect on my choices? How should I assign serial numbers? Should they include some indication of where the instrument was built? I mean, I might move operations to Nashville at some point and that became something of a mess for Gibson. Okay, settle down there champ. We're not even sure if this beast is going to be played in front of the fireplace, hung over it, or used it in it.

So after too much thought, I created a simple drawing using curves in Photoshop and came up with a basic logo. I printed the label on some canvas like printer paper from Office Depot. Though I had not yet seen the movie, someone mentioned that there's seen in "The Red Violin" where a luthier inserts his label into an almost completed violin through one of the f-holes. While I liked the idea of not having to take credit for the product until I had some idea of how it was turning out, I wanted to make sure I could get the label nice and smooth so it would stick well so I opted to put it on while the back was off. With that in mind, I did some searches that led me to Frank Ford's Web site and his description of sticking a label on an instrument. Sometime before this point, I had put together the fact that all those cartoons I had seen where the talking horse is being threatened with being sent to the glue factory might have something to do with the "hide glue" that most luthiers use. I had also been told that the adhesive used on stamps which is activated by the moist heat of being licked (must...resist...urge to make joke... must...resist) is also based on hide glue. I was fairly surprised to learn, however, that there's another product on the market, in fact, at the market, that has the same composition as hide glue: gelatin. So, with Frank Ford's description of mixing the gelatin with hot water and soaking the label, I set the label into place so it would be visible through the f-holes in the top.

Gluing the label 2 Gluing the label Final look inside

Gluing on the Back
Okay, with the label in place, gluing on the back was a simple process. I slid the neck into the dovetail and clamped the neck and top to the table with a block supporting the tail (the same way as when I trimmed the neck heel). Once the neck angle was locked in, I covered the maple rim with colored pencil (to prevent the glue from sticking) and spread glue around the body lining and the point, tail, and neck/scroll blocks. With the back the glue covered rim, it could be moved around to align the points then the centerline then the scroll then the points then the centerline then the scroll... oh crap, every time one was lined up the other were off. Why does glue dry so fast when a problem comes up? Yeah, well, this was the consequence of the saw not being perpendicular to the top of the scroll block when I cut out the scroll from the body assembly. As a result, though the top and back could have been glued directly together and would have been perfectly aligned, the angle of the cut in the scroll block threw off the alignment of the scroll block with the back. Well, this was pretty frustrating, but at least my mistake made sense. Not exactly sure how I'm going to avoid this in the future. Maybe wait to cut out the scroll block until after the top and back are glued on? Maybe use a drill press the drill a perfectly perpendicular outline of the scroll then clean it out with the scroll saw (just thought of this, but I like it). Anyway, I'll do my best to clean this up in the next section.

 Gluing on the back Gluing on the back 2 Gluing on the back 3

Scroll alignment Scroll alignment 2

The last step to attaching the back was to trim the neck button, a little piece of back that protrudes out below the neck heel. With the neck in the dovetail, the outer limits of the heel could be traced onto the wood extending off the back. Because the neck heel will be shaped later, we can make the button any shape we want as long as it's smaller than the outer limits of the heel. Some builders make a sharp "V" shaped heel while others prefer a rounded one. I ended up going with a fairly large rounded heel button. I drew the shape inside my traced outline and followed it with a coping saw.

Neck button

Index of Project


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