Cutting the hole

I finally did it. After much debate, I decided to place the oval hole in the higher position (see an earlier posting) and cut the hole today. I spent a good hour sanding the top up to a 150 grit level, to minimize the heavy sanding after the hole would be cut. I then printed out the oval shape and transferred it onto the mandolin. Ideally the hole would be cut on a scrawl saw but I don't have one. Actually, with this kit, a scrawl saw would not help either because the sides come attached to the top - a source of various frustrations. A deep throat fret saw would be very good too, but I don't have one...yet...;) Therefore I had to use my coping saw and cut it freehand. I had bought some new blades a few weeks ago at Lowes. There were not many options - just one pack. The blades are about 1/8" wide and this turned out to be less than ideal. As narrow as 1/8" seems (when I was at the shop), cutting a tight corner is not easy. I really needed a fine fret saw blade.
Still, I drilled a hole in the oval pattern, and threaded the saw blade through it. The cutting was hard not only because of the blade width but also because I had to keep on twisting the blade in the coping saw frame. The saw "throat" was not large to go all around the instrument so instead I had to keep rotating the blade in the frame. At least the frame allowed for this. I worked slowly, trying to stay away from the line and leave room to clean up.


The hole was cut and left a jagged edge all around.

Cleaning up the hole turned out to be more fun and rewarding than I had imagined. I used the Dremel tool with the sanding drum, working very carefully and "caressing" the edge of the hole until I reached the line, leaving behind a smooth trace. The top of the mandolin has a definite thickness where the hole is cut and therefore, the hole needs to be cut and finished in 90 degrees to the top. I don't have a clear method to achieve that yet.

My plan is to bind the hole using the same binding that I would use for the rest of the instrument.

Learning how to cut shell

It's time to learn how to cut shell and inlay. I had bought some mop and abalone shell pieces from Andy dePaule a while back, and finally got to it tonight. I set up the cutting jig (stewmac) and drew two simple shapes on some tracing paper. I then glued the tracing paper onto mop blanks, using white glue and let them dry for half an hour. Cutting the shell is more enjoyable than I had thought. I like the way the shell reacts to the blade and the cutting was pretty smooth in general. Of course, as expected, I broke a piece of the first design, when cornering too hard. A piece of the shell flew across the room with a 'ping' sound. I also broke a blade on my first piece. No surprise there either. It's expected in the early stages of learning, from what I've read. The second piece went much better. I switched to a finer blade and was able to complete it with both the shell and the blade intact. I put the cut shell under hot water and removed the paper.

The shell dust though is a little bothersome, as it's not good to breath. I used a dust mask and cleaned the area afterwards, but I'm looking for a better place, and set up, for controlling the shell dust. The other thing to consider is getting a head-band magnifier. I'm sure I can get my cuts to be more precise under magnification.

Next time I plan on touching up the cut shell with some files and routing a cavity for it.

Where does the hole go?

The question of the week is: Where should the hole be located? On one hand, I am trying to build an oval-hole mandolin - similar to ones that were produced by Gibson early on in the 20th century. On the other hand, this kit has a neck that attaches at the 15th fret and not the 12th, as is the case with the traditional mandolins. The more I thought about it, the more I saw (at least) two possibilities for the hole location.
Option #1: Locate the hole 3.25" away from the 12th fret, as is the case in the old mandolins.
This option retains the same bridge-to-hole-to-nut spacing as in the old mandolins. However, it forces the hole
to a higher location on the body

Option #2: Locate the hole 3.25" away from where the neck joins the body, as is the case in the old mandolins.
This option retains the same hole location as on the old mandolins, but changes the distance from the bridge to
the hole and from the hole to the nut.

The two photos here show the possible locations. I've been soliciting opinions on this from mandolincafe members. Some information is starting to come in but I'd like to get some more before making my final decision. Right now, I am leaning towards option #1. I've seen at least one example of a hybrid F4 mandolin with an F5 neck and the hole was located as in Option #1. However, I also saw an example of another IV kit where the hole was located as in option #2.

By the way - the photos show the neck in place but it's not attached yet. I just positioned it there to get a sense of the proportions.

In addition to thinking about the hole location, I'm starting to design the headstock. I have several design ideas already. It's clear that the thin veneer on the existing headstock is coming off and a new thicker veneer will be attached. I bought both ebony and rosewood veneers and will pick one depending on the final design and color choices.

Graduation

I completed adjusting the graduation of the top. The process was less than ideal. For starters, the kit came with the top carved thinner the center (and other places) than what Siminoff recommends. The best I could do was try to even it out rather than shoot for specific thickness. I did spend some time on the recurve and I'm fairly satisfied with that part. In addition to taking some point measurements, I also put it up close to a strong light and tried to get an even "color" through the light. This may not be a very scientific way to go, but it gives an overall picture of relative thickness. The hardest part was using scrapers inside the top piece. What would have been a more straight-forward operation, wound up to be awkward because the sides are attached. There is very little room to move around with scrapers. Also, holding down the top assembly was challenging. Here is a photo of one way I was using to secure the top to the work area. I still need to do final sanding and smoothing of the inside, prepping for the braces, before I cut the hole... The hole deserves a posting of it's own