Friday, May 7, 2010

Octave Mandolin Build, Part 10

Leveling the Frets and Cutting out the Peghead
After the fretboard had dried overnight I unclamped it and reattached the neck to the box. I also placed a protective cover over the soundboard in case of any slips while leveling. Using a fret file that I purchased from Stew-Mac I went about the process of initial leveling. After a few passes all of the frets were level (N.B., to find level I kept checking with a straightedge).

Next, I cut a 30 degree angle on the fret ends using a homemade file-gizmo. I took a scrap piece of 2"x4", cut some slots in it which help stop metal shavings from maring the fretboard, and cut the 'handle' at a 30 degree angle on the table saw (you could use a band saw just as easily). Then I placed a strip of double-sided tape on the block and attached a file. Moving back and forth on both sides of the fretboard, holding the file tight to it, I was able to achieve the angle on the fret ends that I wanted.

After that was completed, I used a number of small sanding blocks to polish the frets - going from 120 grit up to 2000 grit.

I then taped between the frets. Using a small triangle file I 'rounded' the fret ends by using a downward sweeping motion right-to-left and then left-to-right on each of the frets. This helps to remove any rough spots on the fret ends. When that was completed, I hit the frets with some steel wool, and removed the tape to see a nice shine.

The next thing on the agenda was to cut out the peghead. Finding the centerline, I traced out the pattern on the peghead veneer. To get the proper angle for the headstock, nearest the nut, I clamped the neck into the jig and started cutting it out.

However, I didn't want the sides of the rest of the peghead to be angled, so I traced the pattern on the back of it in order to have a flat surface (i.e., the 'top' of the peghead) on which to cut. But, I ran into a little bit of an issue - the fretboard, nearest the nut, would not allow the peghead to sit flat on the bandsaw table. To correct for this, I planed down some scrap wood the thickness of the fretboard and attached it, using tape, to the top of the peghead. This allowed me to get a nice cut.

To finish up, I initially sanded the cut sides using a sanding drum on the drill press, and then finished them by hand sanding down to 320 grit.

Sunday, May 2, 2010

Octave Mandolin Build, Part 9

Fretting and Gluing the Fretboard to the Neck
Don's kit came with a pre-sawn fretboard. So, I marked and drilled the holes for the position markers, dropped some CA in the holes, and inlayed them. After dry, I sanded with 100, 150, 220, 320 and 400 paper to level the position markers and to get a smooth surface. It looked like this after sanding was completed:

After everything was sanded I then fretted the slots. I took an old scrap 2"x2" I had in the shop and drilled a number of holes in it to hold the fret wires so that they didn't get all mixed up after being cut. Starting on the side closest to me I 'set' each fret with a quick blow of the fret hammer. I then tapped across the fret to the opposite side of the board, and tapped back towards me. Most of the frets set well, though there were a couple that I had to go back and give some extra taps.

I then took a pair of nippers that I ground down flat and clipped the excess overhang as flush to the fretboard as I could get it. Once that was complete I was prepared to glue the fretboard to the neck . . . however, I ran into a little problem. One of the videos I have shows a trick for holding the fretboard in place while clamping it. Instead of pre-drilling pin holes and inserting a pin, the video demonstration showed using a staple gun, shooting a staple into the fretboard, and then just clipping of the extra 'side' of the staple. 'Simple!', I thought. However, my staple gun was made circa 1960 and is still as powerful now as I'm sure it once was. Needless to say, I shot the first staple in without a hitch, but the second one shot through the fretboard and split it out. What made this all the more shocking was that I was holding the staple gun a good inch from the board!! Here is a picture, after I had pulled the staples and fret out:

Thank goodness for CA glue! I used the thin stuff and it completely filled in around the cracks. I clamped it together really quickly (being sure to cover it in wax paper before clamping) and let it set. Once dry, I sanded it down on both the front and back, and reseated the fret. It came out pretty well.

The next step is to center the fretboard on the neck, but in order to do that you first need to have a good fit between the neck and the box. Kawalek's kit comes with a mortise block and tenon neck, which actually makes fitting the box and the neck a snap. First, you need to remove the bit of soundboard covering the mortise. I did this using a pull saw and an exacto knife. Next, I placed a piece of self-adhesive 120 grit sand paper over the mortise block, and using a razor blade, cut out the area directly above mortise itself.

Here is the cut-out:

Here is the sandpaper on the mortise block:

After the sandpaper is in place, you need to insert the neck into the mortise, and using even downward pressure, slide the neck back-and-forth sanding the tenon joint until you start to see sawdust showing clearly on the paper. Be sure to check often, and try not to sand too much. You just want to make a nice tight fit. Here are some pics:

Once I had a tight joint, I then loosely tightened the bolt and layed the mando down on its back. From here, I followed Don's instructions for centering the fretboard. First, I inserted the nut. Second, I sanded the nut end of the fretboard to fit the angle of the nut tightly. Then, I found the center of both ends of the fretboard, as well as the center of the soundboard. Getting all of the lines straight, I clamped the fretboard in place and marked its location on the neck and on the soundboard. I also laid a straightedge along the side of the fretboard and marked where it would line-up at the tailblock. When everything looked good I removed the neck from the box. I took the neck to the bandsaw and removed the excess from it, almost to the line I had drawn for the fretboard. After checking the 'flatness' of both the neck and the bottom side of the fretboard, I then glued and clamped the fretboard to the neck. (N.B., be sure to make a clamping caul so the fretboard doesn't get scuffed up by the clamps.)

And, here it is all clamped up:

Friday, April 23, 2010

Octave Mandolin Build, Part 8

Gluing the Headstock/Peghead Veneer
Kawalek's kit came with veneer for the top of the headstock, but I found a piece of cherry at the the local speciality woods store that had a nice 'flame' to it and decided to use it for both the front and back of my headstock. I cut off a length of the cherry long enough to cover the peghead. I then resawed it to about 8mm thickness, and stuck it under the planer until I had a thickness of about 5mm. I also had to take a little off of the back of the peghead itself to get the overall thickness (once both pieces of the veneer were glued on) to the proper dimensions. Here are some pics.

In this one you can see that both pieces of veneer (which have been dry clamped) are still too thick, as the tuning machines won't be able to work.

Getting closer . . .

And, finally . . .

Once I got to this point I stopped planing, as I knew that there would be some sanding to take an additional 1-2 mm off the veneer. I then drilled two 1/16" holes in the veneer to hold it in place with brad nails after I got it glued up, but before I could clamp it. I also marked on the veneer which piece was for the top and which was for the bottom of the peghead. I then marked out the size of the truss rod slot on the top piece of veneer so that I would know where to cut and chisel it out. Here are some pics:

Notice in this picture I have the nut inserted for two reasons: 1) so I know exactly where the veneer needs to be; and, 2) so that I can angle the piece of veneer, by sanding it, to sit flush against the nut once it is glued in.

And here it is all clamped up. Be sure to use a couple of additional pieces of wood to help in the clamping. That's all there is to it.

Wednesday, April 14, 2010

Octave Mandolin Build, Part 7

Cutting the Binding Channels and Installing the Bindings
Before I routed the top and back binding channels, I coated the edges with clear shellac in order to minimize tear-out. There are numerous opinions out there concerning whether this step is or is not necessary. But, because I am insanely anal retentive about certain things, I went ahead and shellaced just to be sure.

Depending on how wide and how thick your binding is will dictate the depth and width of the channel you route. When routing, it is usually best to take two or three passes (changing depth and width after each), rather than trying to route the entire channel depth/width all in one pass. The picture below shows one route, and then the second one started. Hopefully the picture is self-explanitory.

Here is the back fully routed.

Once the route is complete you can apply the binding. Since my binding is made out of ABS I used CA glue on the back (on the soundboard I used Titebond wood glue . . . as a test). It is a good idea to get everything set-up and ready to go before you start gluing. So, you will want to make sure that the binding channel is completely clean and level. If it is not then you can chisel out the areas that need work. You also want to have a number of pieces of tape cut and ready to go (see the pics below) to 'clamp' the binding once glued. Starting at the neck block, place a little glue in the channel, fit the binding, and get a couple of pieces of tape on it (place the tape on the back and/or soundboard first and then pull it tightly over the edge, securing it on the side). As you progress try to lap each consecutive piece of tape over the previous one to aid in the tape's holding power. Here are a couple of pictures:

Be sure to give the glue adequate time to try before you remove the tape. After you do take the tape off, you will then need to scrape and sand the binding. I used hand scrapers to remove the majority of the excess binding and then sanded the rest. Here is the back after those steps were taken:

Here are some pictures of the binding of the soundboard:

One of the things that I should have done was shellac the top a little more. As you can see from the picture below, when I took the tape off some of the fine fibers from the soundboard, where it was not shellaced, came off with the tape.

Here is the soundboard and back binding completed (N.B., if you were worried about adding the shellac, don't. The single coat very easily sands off).