Back to the Back

I'm down to detailing the contours of the carving around the edges, particularly on the underside. I've opened up the inside scoop quite a bit, which will make more inside space for resonance. The overall thickness of the back averages about 4mm now. There is still a tad more work to do around the contours to bring the thickness down, but it's almost there.

The outside of the back is pretty much there. I've been gradually making it smoother with progressively finer sandpaper. Although it is vaulted somewhat, the back is essentially flat near the middle. This is an unusual form to carve an archtop into. Some would probably say you can't carve it that way and expect it to sound good. We'll see what happens when it's done and I get a recording of it being played.

On The Level

Now the task is to make the outside of the back level before I start to carve it down to match the inside contours. I am doing this with a very old Stanley plane I found at the flea market. It needs proper sharpening, which I am working on, but I was able to get it sharp enough to bring the laminated sections down to pretty much level. The centre piece is actually the level I'm going for. I wish the others had been the same thickness but that's just the way I got them, and I don't have an electric planer.

As you can see, there are variations in the grain patterns. I actually wanted that for this guitar. Most builders go out of their way to get a consistent grain, but I'm going for a look that will evoke the feeling of an old style radio, which often made use of wood grain in a different way. As I progress with the back, I will simply add new photos to this post, as I did with the inside carving earlier.

The Inside Scoop

I actually started the guitar back some time ago. Even though I've been carving on it for days, the depth of the scoop is hardly apparent. It's actually deeper than it looks, but it's still going very slowly. This is the inside scoop... so to speak... I haven't started carving the outside contours yet, as I want the flat underside of the back in place for stability while I carve the inside.

The spoke shave I'm using is flat-bottomed, which makes the task ... tricky, to say the least. I'm able to use it somewhat here and there, but as the depth of the scoop increases the usefulness of this tool decreases. I'm looking forward to the arrival of a convex spoke shave. That should make this project go quite a bit faster. The brass round bottomed luthier planes are great, but they don't remove a lot of material at a time, and they get hard on the wrist when you use them for a while.

I decided to just update this post rather than make a new one. I've been working on that back for a few more hours, and it's getting to the point where I can actually see some progress.



As of January 27, I'm still carving. Getting into the tight little area inside the "horn" is made much easier with this awesomely tiny convex plane. The pictures don't show the depth of the carving very much at all. I'm a whole 7 mm down, believe it or not! It looks a little rough at this point, but there's still a ways to dig. I'll get more refined with my carving as I approach the depth I'm after. I can no longer use the flat bottomed spoke shave in the picture up top.



As of Jan 28.... down to 8mm depth. I figure 11mm is how far I need to go, so it's no longer as daunting as it used to feel.



January 30. As I carve this thing, I don't really see the progress. It's only after I take a photo and compare it to the previous photo do I see the changes. I admit I took advantage of some helpful lighting from the window across the room; the carved area is actually somewhat exaggerated in this pic due to the shallow angle of the sun, but wow! what a difference between this and the one up top of this post. I'm down to just touching 10mm depth. As mentioned before, I'm headed for 11mm. So close I can almost taste it... wait, that's wood shavings in my mouth. Darn things get everywhere! A little more digging inside then I can clean it up and start the outside carving.

Carving the spruce top.

I never ended up getting spruce billet for the top. Instead, I decided to just go with some lumber and re-saw it so it was quartersawn*. I had to laminate a lot of strips together to get the width (narrow boards), but I read somewhere that this may not affect the tone as much as some might believe - I guess we won't know 'til it's done. I'm not interested in getting the perfectly clear look with no "imperfections" that many luthiers favour. I much prefer the "real wood" look that comes from grain streaks and knot shadows.
At any rate, the top picture is carving in progress. Notice the cool little brass plane. This has a rounded bottom to allow for scooping out contours like those around the edges, and inside.
Further along, you can see in the second picture how I've refined the curves and made it a more gradual incline toward the centre.
The inside is currently being refined to match the outer contours I have settled on.
*For those who are wondering what "quartersawn" is - this effectively refers to the direction the grain is going. In a softwood guitar top, you want the grain to be oriented up and down (as you look at the end of the wood), rather than side to side. This makes for a stronger and more stable top than if cut the other way. This is why you almost always see a tight, narrow grain running end to end on a guitar top. Almost all lumber is cut flatsawn, which is simply cutting the log into slabs. The slabs from near the centre may be effectively quartersawn on the outer extremes because of how the grain is running, but most of it runs laterally, or close to it.