For a number of reasons, I’ve been spending more time than usual working on the mandolin. First off, it’s actually starting to look like a mandolin, so there’s more interest in working on it now than when it was just a bunch of sticks and sawdust. It’s also a very pleasant summer here, rarely getting above about 23 degrees or so (75 or so for those that are Celsius challenged), quite unlike the oven that most people have been living in this summer.
I’ve also been on some wonderful painkillers and lying low over the weekend, waiting for tomorrow morning’s root canal, but that’s another story that I’m not really looking forward to.
I had a few things to finish off on the neck and headstock, so let’s start there. I put a layer of nice maple veneer on top of the headstock to cover all that funky finger-joint stuff, stealing a slice from the pieces I have for the sides.
You can see some of the wonderful figure in this maple
That went on nicely, and I fashioned a cover for the truss rod out of small layers of padauk and maple, niftily held in place with cool 1/8″ rare earth magnets (thanks, Lee Valley!). Most instruments have this cover held on with a couple of small screws, I like this a lot more. Even watched the polarity of these things so you can’t put it on backwards. Simply put it back somewhere close to where it should be, and it jumps right to where it should be, nice and firm.
The truss rod cover - gotta love those rare-earth magnets!
Well, that was enough delaying – I had to dive in and play with that wood that I bought for the sides and top and back at some point. I started with the sides, which meant I had to find some way to bend the maple in to the right shape.
Why spend $200 when $10 will do?
Like many things, you can easily go online and find very expensive solutions to the challenges you face when making instruments, but that’s not what this is all about. Rather than drop a few hundred bucks, I went and bought about $10 worth of pipe parts and borrowed a neighbour’s heat gun. Voila! An instant side bender, if you want a sharper bend, just throw on a narrower pipe! The thing gets hot enough to vaporize water in a couple of minutes, and it’s a bit safer than most home-grown solutions that just blow a torch into a length of pipe.
Once I get the hang of it, the sides bend very easily. Soak ‘em for about 15 minutes, back ‘em up against the pile with some steel strapping behind them to hold in the steam, and apply a lot more pressure than you would think the wood will take. Nice, clean bends, and I’ve got all the wood I need bent in a couple of hours (most of which was practicing).
Look ma! No forms!
There are a few things that I have decided to do which is against the standard practice for most builders. One is the use of forms: the first thing most builders do before they even touch any wood for their instrument is to build a form. It’s in the shape of the final body, sometimes very elaborate, with all kinds of medieval turnbuckles and stuff used to force the wood into its final shape, literally to bend it into submission.
Maybe I’m lazy, maybe I think that building the instrument all trussed up in a form is a great way to lock all kinds of stresses into the body, which can’t be good for the wood doing what it wants to with sound. For me, it’s no form. Let the wood be free!
The body sets up quite nicely without that form, and it’s nice to know I don’t have to store some sort of behemoth contraption somewhere around the house just in case I ever build another one of these things (or worse, have one of these things for every different style of instrument I make).
Another thing that I’ve done that is against standard practice is a nice touch that most people never think of, or even see. Because the sides are so thin, instruments have some sort of lining on the top and bottom of the wall to increase the gluing area. In most instruments, for expedience, these are made with kerfed strips (you can buy these, too), simple wood strips with saw cuts every 1/4 inch or so to make them easy to bend.
How tacky!
I went with something that took a little more time, but looks a little better, even if nobody will ever see it. I laminated up thin strips of mahogany and spruce into the right shapes, rounded the internal edges, sanded them smooth as a baby’s bottom, and used these instead. The result is a very stable body for the mandolin, just the right shape (without a form), all ready for the soundboard and back.
...just waiting for a soundboard and back and neck and strings and...
Ah, that soundboard. Decided to tackle it first, as Sitka spruce is a helluva lot softer and easier to work than maple. Glued the two book matched pieces together and laid out the shape, then laid out some contour lines and used a router to carve out a series of concentric rings, each one 1/16″ deeper than the previous one, into the middle (inside) of the dish, kinda like those rice paddies you see built on the side of a mountain in Vietnam. A very little elbow grease and a decent sander, and very soon I have a nicely dished inside to work with.
Maybe I should be in the bowl-making business
But then there is the other side to contend with. The blank is still close to an inch thick, and by the time I’m done I will have to remove at least 80% of all the wood I’ve got in front of me.
The inside of the soundboard...
I cut it to final shape, then attack it with the router again. I start by bringing the whole thing down until the middle (measured between the two sides) is only .2 inches thick, then bring the outside down to the final thickness, then roughly (but in thin passes) rout down so I’ve got those familiar concentric rings to sand down to oblivion.
After a couple of hours (I have to go slowly, as I’m doing a lot of freehand router work on a surface that is not flat), I get the outer shape fairly close to where I want it.
...and the outside...
I’m sure the back, a huge solid chunk of maple, is going to be a nastier piece of work!
I still need to do a final thicknessing on the front, cut the f-holes, and tap-tune the soundboard after I attach it to the body, but that’s for next time.
