Master Luthier William Cumpiano

Builds a Koa steel string acoustic guitar.

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Tutorial Contents:

Introduction  
Workshop  
Soundboard  
Back & Sides  
Neck,fingerboard  
Binding,purfling,inlay,veneer
Bridge, setup
Tools & Jigs  
Q & A  

Tools and Jigs
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An opening shot of my tool room: compact, minimal--the way I like it.
This is the beast that's going to reduce the sets: my home-made abrasive planer. Although rather slow, it gives me superb accuracy (I can sand slats down to .008 veneers with it). Relying on main helicopter ball-bearings, It's given me 30 years of flawless service; I've built my entire career around it. It avoided me having to spend $8-11,000 on a real-world wide-belt abrasive planer. An early apprentice dubbed it "Big Joe D'Sanda" and the name stuck.
Here's my neck blank fixture. The long block is fixed, but the short block is screwed on one end only, so it can rotate to accommodate the angle of the headstock.
Here's another angle with neck blank parts.
Neck blank parts clamped in place. The idea is that you can align and clamp both elements from sliding apart while you clamp the glued scarf joint.
Glue joint clamped. Cauls are used every where to protect the workpiece from clamp marks and/or spread the clamping pressure over the entire glued seam. Three clamps placed vertically across the scarf seam is sufficient. Take care of c-clamp pressure. They throw far more pressure onto the seam than the sliding bar clamp. So crunch the bar clamp down but tighten the c-clamps moderately.
Heel block glued and clamped on the jig.
My most common templates used are 000, M, and classic. So for these, I bend the sides on a mold over a heating blanket. The molds consist simple of multiple medium density particle board templates bolted together. Two gadgets which I find indispensable are a good rheostat and (just barely visible in the upper right hand corner) a digital thermometer. The slot in the waist block help keeps it aligned. The sides are soaked in cold water in a galvanized steel trough for about 20 minutes, and then placed on top of the blanket when it has reached 275-285 degrees, and pressed down at the center first, sloooowly, and then summarily the ends are brought down and pinned by the cauls and cam clamps. It's left to "cook" for about a full minute or so, then shut off. I find if I leave the whole thing sitting like this overnight, I get virtually no springback later. That's why I have to start bending early in the process, because four sides will take four days.
Here are some photos of our jointing device. The idea is almost exactly like a power joiner but it's made of wood, and instead of a spinner cutter head, it uses an upside down plane.
In the bed is an old unused wooden smoothing plane that I once got as a gift but never used.
A two-point suspension device for the plane allows easy removal for sharpening and adjustment.
Another view of the cutting bed. As the blade wears, I can push the plane in a bit to expose fresh blade.
The fence and the secondary beam keep everything aligned and rigid. A couple of years after building it started to sag a bit and it began to cut a slight sweep in by sound boards. So I disassembled it, re-jointed the fence and secondary beam, and it became true again. Now I put a small "foot" to help keep it from sagging.
Here's one of our joining fixtures. The ebony disks are eccentric, turning them into cams. Multiple holes have been drilled for their pivot screws to accommodate different size soundboards, as do the hinged fences on the left.
The jointed top gets joined on the joining fixture. Pretty self-evident. Turning the ebony cams exerts pressure on the soundboard seam. The hold-downs make sure the thinned-to-dimension plates align properly during gluing.
Here, I use my partner Harry Becker's ingenious headstock drilling and shaping jig. After using the jig for drilling, it's removed, flush-bolted to the headstock and used as a router platform for shaping it's outline.
The plane marks are sanded off with this miniature sanding plane. My old colleague Ivon Schmukler or Artisan Fretted Instruments taught me how to make these. I have a dozen of these, in all shapes and sizes: very handy, and keep your fingertips from getting scorched from vigorous sanding.

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