Now for Something Completely Different

About a year ago, I told the story of a guitar project I was starting on.  To summarize, a friend had given me an odd "junk guitar" with most of one side cut away.  The story is that the manufacturer, Breedlove, had made it as some sort of demo piece that showed how well they were made by showing what the insides of the guitars were like.    

It has a solid Sitka spruce soundboard (top), which isn't uncommon once you get past the very cheapest guitars; the back, though, is solid rosewood and that's something I expect to find only in fairly high end guitars.  The closest equivalent I know of on the market today seems to be the Fender Paramount PM-3 Deluxe at a K-buck.  The sides are rosewood laminate (plywood), but a guitar's sides are largely structural and don't affect sound very much. So while it has an obvious problem, it's basically a good guitar, not one of those cheap, plywood guitars for beginners.  In other words, while it's a junk guitar because of how it was cut up, it's not a "junk guitar".

Last September, I replaced the missing parts (with the exception of the electronics) to make it playable, and I've been playing it at least once a week as my primary acoustic guitar.  It sounds remarkably good.

All the while I've been trying to come up with a way of restoring it.  The problem is that the shape of that cutaway isn't a piece of an oval, a circle, or anything that looks like a conventional guitar's waist.  I'd have to turn the cutout shape into something I could match exactly to make a solid top with the right shape, and I'd have to rebuild the top and back.  I might have to remove the neck.  I'd need to replace many of the braces inside the box; you can see some of the braces on the back; the braces on the top are a more complex pattern and really a science of their own.  Getting the wood to rebuild the top and back would essentially mean buying the wood to make a whole new guitar, and it would probably take more work than making a new guitar from flat pieces of wood.

What about just putting a piece of wood over the hole?  I started looking into that and found it to be harder than you'd think.  The wood used in guitar making is very thin compared to standard lumber, which has lots of advantages, but means you just don't find it at the Orange or Blue Borgs, you have to buy it from a luthier supply place.  After you find it, the wood's typically sold as a separate top and another species sold as the back and sides.  From time to time, during thickness planing or sanding, a side will get broken and the remaining piece set aside and sold as a practice or "orphan" side.  For a few reasons, I had decided I'd like a light wood, preferably figured maple.  The problem with that is the places who sell these orphan sides tend to say, "no selection"; "you'll get what we have the day we get your request".   One of the major online suppliers told me they'd be happy to sell me two sides at full price, if I'd like, which came across as less helpful than they might have though. 

Somewhere along the line, somebody suggested I replace the side with a piece of clear plastic.  The guitar will always be an oddball, one-of-a-kind instrument, so since it was originally intended as  a showpiece of what it's like inside a Breedlove guitar, this will keep it that way.  I finally went down this road, using some clear plastic left over from building my mill's enclosure.

Since holding the plastic to the guitar has to be designed in, I decided to use pieces of wood called kerfing, for the multiple saw kerfs cut in it.  The first step was to cut this into pieces and glue them to the top and bottom of the body, emulating the way the existing kerfing is positioned.  This picture shows the bottom kerfing already glued in place and the top kerfing being held by rubber band clamps. 

With the kerfing glued in place, the next step was to rough form the plastic.  I made a form by tracing the outline of the body's cut onto some scrap 1x pine, cutting that out with a jigsaw and then smoothing with sandpaper.  After that, I clamped the plastic to the high spot on the form and heated it with a hot air gun.  As the plastic softened, I could push it down onto the form with a long-bladed screwdriver and after a few seconds, it won't spring up anymore.  Much.

Then it was time to go through a cycle of test fit, mark overhang on the plastic, cut it off, and repeat.

As you can see, I put a sound port on the side, like so many high-end custom guitars have these days.

Finally, the real purpose of the kerfing.  In a production guitar, the sides are glued to the flat surfaces on the kerfing.  I thought that for this guitar that it might be best to use wood screws on the sides, because wood glue doesn't work on plastic and epoxy is too permanent.

I suppose it's typical for me to say I'm not sure if it's Done done.  Before I smoothed the plastic to make it match the body's top and back,  I put a new set of strings on it and played for a half hour.  Adding the side didn't mess up the sound, that I can hear.  With the sound port where it is (even though it's not perfectly centered - aarrgh!), it still sounds good from where I'm sitting.  The second thoughts that I have about being done center on how butt ugly it is.  I might do something like stain the light colored wood of the kerfing to make it a bit less glaring, and in-your-face.  I need to learn a bit about options and what I can do to make it look a little nicer, if possible.

On the other hand, it's not like I'm playing in clubs and lots of people will see it.  It'll be under my right arm and held up against me while I'm playing.  Then it will live on a stand until the next time I pick it up.