Sycamore thumbscrews

Maybe I shouldn't call him PH; that's just what he called himself after we played with photobooth on my macbook and produced the photo atop the last post. Actually, it's EclecticGuy of OccasionalBlog. He and I met 35 years ago when I was whistling "Thick as a Brick" in junior high school gym class, and he recognized the tune. We've been talking music ever since. He's a great friend and an outstanding musician who's taught me many, many things. So I'm charged beyond words to be making him an instrument.

Anyway, this goodie is a side bender. When you get the back and side set from your supplier, the pieces need to be thicknessed and trimmed. I've learned that prior to using the bender you must mark the sides. Then you give 'em a healthy dunk in some clean water and make a sandwich. After you've eaten, you make a sandwich consisting of, from the bottom up, steel slat, side to be bent, bending blanket (an electric goodie which heats up to 450 degrees -- though you don't want to get it that hot), and steel slat. Slide it into the bender and tighten the waist press. Turn on the blanket and wedge a cooking thermometer between the upper slat and the blanket (I usually put it between the waist and the hip). Monitor that temperature, baby! When it says 225, start screwing down the waist press. Take it all the way down! (But, of course, stop when you hear your wood break. If it does, break down and cry. Then back out and try to fix it with glue and voodoo. If the wood gods are with ye, breakage will not occur. The sycamore sides I bent the other day might as well have been made of rubber -- over 1/8" thick, but bent easily, and held their shape nicely. But I digress.) There are two spring loaded thingies you can slide from the waist up and down over the bouts. Do this slowly to avoid breakage.

If by now you've not turned off the blanket, it's 350 degrees, and your sides are rapidly attaining charcoalhood. So, throughout this process watch that temperature! Different woods take heat differently. This Sycamore bends at low heat but tends not to char. Mahogany seems to like more heat for bendability, but will char. I've had no trouble bending flame maple, but it seems to be happier with more water and higher heat. Cocobolo bends nicely, but is so oily you have to scrape off cooked sap. Yuck!

Here you see clamped into the two halves of the external body mold the results of bending. I am delighted with how well they turned out.

Here's a lovely partially braced mahogany top (for the sycamore guitar). It sits on a towel covering a dished workboard. The workboard is covered with sandpaper -- hence, the towel. The surface of the workboard matches the surface of a sphere of radius 12 feet. That's a fairly standard workboard for the back, but tight for the top. Some guitars I build have tailpieces, so I like a tight radius.

How does this bracing get done?

Here are two lower face brace blanks. You can't really see it in the photo, but the planes of the grain lines run parallel to the largest surface in these rectangluar timbers. That's what you want for stiffness. So, I pull the top and towel out of the way, and grind one edge of each blank against the sandpapered surface of the workboard, thereby transferring the 12 foot radius onto the glued edge of each brace. Slick! Then I use other sophisticated devices (i.e., a nice flat hunk of MDF with sanpaper glued on to it) to give the rest of the brace its shape.

This dandy is called a go deck. I don't know why. But it's really a cool and low-tech way to get braces glued in place. I spread as thin a layer of glue as I can manage on the curved edge of the braces with a stiff bristled little paint brush, put the brace in position, surmount the brace with a wood scrap clamping caul, and hold it in position with these fiberglass go sticks. Each one exerts a surprising amount of pressure, and collectively you can create firm and even pressure to get your top and back braced.

Finally, I installed neck and end blocks in the sycamore guitar. Here the wood is being tortured with glue and clamping pressure, forced to do my bidding. BWAAAHAAHAAA!