Arch Top Beginnings

Last term, since we had finished up a little early on the classical guitars, we got to spend a couple days working on the new arch top guitars. We made pretty good progress in the two days we used last term, but since students tend to slow down on their arch top guitar, they are really pushing our pace and treating this term as if we were starting out on week two. Kind of a lot to ask for since it wasn't a full week we used last term. At the end of this week we had not gotten quite as far as they would have liked, but close. It looks like I don't really have pictures of all the work I've done, but I'll have some more pictures for you next week, and I can tell you all about what I do have done.

This is what the top and back plates look like after we have book matched them. We drill four large holes that are used for locating the work on the duplicarver table. ...Yes, we do the bulk of the work on a duplicarving router table. It's probably actually a good way to start when you are building your first one, but once I'm home, I think I will practice up on carving them without the duplicarver. We use the router for carving out the rough contour of the outside of both the top and the back. After this process, the plates look about like this second picture here. This is actually the maple back in both pictures; The top is spruce. Once the plates are to this stage, we use a template to trace the profile of the guitar into the routed area. Then we cut out the shape being sure not to cut through the line, as the line is not over sized at all and the only cushion you have is what the binding thickness will eat up. (not much)

So after the plate is cut to shape, we use a spindle sander to sand the profile right up to the final line and then use a router to cut the edge to its final thickness, which is 3/16". This plate here with the plane sitting on it is the aforementioned spruce top. We have to smooth the contour of the plate's inner portion into the final thickness edge we just cut. We use that little plane there for this job

The surface of the edge is colored with pencil to help you see if you are hitting it with the plane. Since it is already at final thickness, we do our best to not hit it.

After the contour is blended into the edges with the plane, we have to scrape and sand the contour completely smooth so that there are no high or low spots. The scrapers will do a better job of blending than just sanding will, so we do our best with the scraper, and then finish up with sand paper. The sandpaper alone could make it appear to be smooth, but when held to the light may show shallow spots that will only be more obvious once the glossy finish is on it. The outside must be completely shaped and sanded before we start carving the inside of the plate in order to keep our desired thicknesses in check.

When we are ready to carve the inside, we set up the drill press with a depth stop, registering off of a pin rather than the table. This allows us to drill holes all over the plate to precisely the final thickness. We then use that trusty finger plane to bring the material thickness down to the bottom of the holes. It's really pretty fool proof. But, this is where it's obvious why arch tops should cost a lot. I have the hands of an old-timer today.

So long story short, my plates are now done. We used another router jig to cut out the F holes on the top. The jig fits over the whole top from the back side, and locates off of the holes in the excess wood at each end of the plate. I also made a lot of progress on the bridge and saddle for this guitar. I got the sides bent and glued up the the head and tail block, and even cut out the pearl inlay for the headstock. Sorry I don't have pics of that stuff now, but more soon!