Day 4: Carving back bracing, kerfed lining, picking soundboard and cutting the neck.
Wow, got a lot done today. Piece by piece it’s coming together. Things I expected to be ages away are happening now. Think I’ll miss the process when it’s all done. But there’s still a way to go.
Carved back bracing:
To continue from my carving efforts I used to chisel to carve a dip on the ends of the back bracing inside the guitar.
The reason for this intrigues me. When you have finished creating the body of the guitar, bracing and all, glued all the sides, back and front together, you then need to TUNE the guitar body (you are tuning the sound of the TAP when you tap on the front and back, NOT the sound of the strings, as this is before the strings are put on). I’m not yet sure of the specifics of what note to tune the guitar to, but for example, when you tap the front of the sound board, the tap sound should be a G. When you tap the back of the guitar, the note should be a G#. The idea of carving the back bracing to this particular shape, is for later when you need to tune the tap of guitar. If you need to bring the note of the soundboard up a tone or even more, you need to reduce the MASS of the soundboard bracing quite significantly. Therefore you need to stick your hand in the hole and sand of masses of the length of the bracing. If you only need to fine-tune the note, then all you need to sand is those edges with the curves on them, to take off a small amount of mass and change the note. I suppose you start with a large mass, so you can reduce the mass and raise the pitch slowly, as it would be difficult to ADD more mass.
I continued chiselling the bracing, followed by more sanding. We’re told to keep it as neat and tidy as possible. I’m attempting to make it look as professional as a bought one, but it’s a lot harder than mass produced parts and machine-made instruments. Everything has to be precise, and you have templates and rulers to work with, and accurate tools to use, but at the end of the day, my hands are sculpting this, sanding, sawing, carving… and I wonder how much of my humanly flaws will come through in this creation….
I’m interested in taking a tour of Maton to see what the difference is between how I am making a guitar and how they make guitars.
Creating kerfed lining:
I had no idea what kerfed lining was. As I found out, kerfed lining is inside the guitar. It is a strip of wood with slits in it, about 8mm apart. The slits create flexibility in the wood strip, so it can follow the contours of the guitar. It’s used to join the sides to the back and front inside the guitar, by creating a larger gluing surface area to grip to, as opposed to just joining the 2mm sides directly to the back/front.
I’d seen the kerfed lining from other students’ work, and wondered how on earth you get all those little slits in the wood, so evenly spaced, evenly deep, and so it lines the entire guitar’s edges inside. How do you not cut through the entire strip of wood?
I started with one chunk of Queensland Maple, about the size of a face of an ipod but…. 1m long. From that, I measured and cut out 4 pieces on the band saw 6mm x 17mm x 1000mm. I used the drum sander to then reduce their dimensions further and create smooth, even strips of wood 4mm x 15mm x 1000mm.
Once I had these strips I was to take off one edge of each strip, all the way along the metre length. This was then sanded off to create a smooth, rounding appearance on that edge.
I used the band saw to cut all the little slits. Chris had a home-made template to align each strip up with, and limit how deep it cut into the wood. All I had to do was press the strip into the band saw as far as would go, then move along and align it with the template again and press for a new slit, 8mm apart, all the way along length of the metre strip, for each of the 4 strips.
Next I was to create tail and neck blocks (also made from Queensland Maple)
I had to cut these chunks of wood down to size
Tail block: 15 x 52 x 110mm
Head block: 45m x 60m x 100mm
I then had to cut a 4°degree slope onto one end of the tail block and one end of the head block. This is to account for the curve in the back of the guitar. If we didn’t do this, the tail and neck pieces wouldn’t sit up straight and wouldn’t create stability for the sides.
Creating the soundboard:
Picking a sound board is a crucial part of getting the tone of a guitar. Chris offers a range of quality timbers for the soundboard – including Tasmanian King William (Billy) Pine, Queensland Bunya Pine, and Tasmanian Huon Pine. I can’t begin to understand the complexity of timbers, and how their ages, densities, thickness, shapes, types affect tone. I’m told the age of the wood creates a greater density, which has a lot to do with creating great tone. These types of wood are becoming rarer, as they are made from hundred-year-old forests and older, it’s not something you can plant and grow tomorrow for your new guitar.
Chris suggested Bunya Pine to compliment my playing style, and the intricate melodies I pick up the neck. I trialled different guitars with varying soundboards. I was particularly interested in the deep bass “doof” sound when the guitar is thumped – creating a bass beat by palm doofing the bridge/soundboard is an integral part of my playing style. I loved the deep bass sound of King Billy soundboard, but it’s too mellow for the treble sounds I need picking for the intricate melodies I play up the neck. Bunya Pine creates a brighter sound. That said, there are a lot of things that create the tone of the guitar, not just the soundboard. Other timbers of the rest of the guitar affect, as well as the shape, thickness of the guitar, etc.
I decided on Bunya Pine.
The same process is carried out for creating the back of the guitar. Selecting the timber, tracing the shape onto the soundboard, making sure it’s free of knots, cutting straight edges for a clean join, gluing the ends together like book ends, clamping it down and leaving it to dry.
Creating the neck:
When I made a guitar in high school I just bought a neck, fretboard and all.
But this will certainly be something carving a neck, and inserting every single fret into the fretboard.
I started with a chunk of Queensland Maple.
I ruled a centre line down both wide sides of the wood.
I drew lines across at 125mm and 200 mm. I drew a diagonal line on the narrow side of the piece of wood, from the 125mm making to the 200mm marking. I then cut along this line to create this shape:
This is to be the head of the guitar. It gets flipped around and reattached to the neck on an angle (to create string tension).
But before reattaching I had to flatten the slope I just cut, so that when it’s reattached the join is as accurate as possible. This took a while and I didn’t love it. Sanding on the belt sander, sanding by hand, grinding more off, sanding again, always checking with the straight of a ruler to see if there were any irregularities in the slope.
Once straight, I re-glued the head back onto the neck like so:
We’ll leave this overnight to dry.
I’ll have to research headstocks to come up with a design/shape I want for the head.
Leave a Reply
Want to join the discussion?Feel free to contribute!