Attaching Head and Tail Blocks

Today we took the bent sides out of the side bender and fit them into the mold. Mike showed me how to butt the lower bout center seam so that it is almost undetectible and so the grain of the wood lines up on both sides and seems to be continuous.

Fit sides into mold

1. Put one side into mold and make sure the bottom of the side is flush with the bottom of the mold. Screw inside clamp with turnbuckle to hold in place. Push side at upper bout with your hand and mark center line. Do the same with the lower bout.

2. Now this is a cool trick! Take the side to your bandsaw and hold your side vertical to the blade. Cut your centerline like the blade is going through a thick piece of wood. The blade does not know how thick the wood is and will make a nice right angle cut that will match up perfectly with your other side. At the bottom of your uke you will have a seamless joint and so will not have to add that bottom graft. The only reason you will add that graft is for aesthetics and not to hide a seam that was less than perfect!

3. After the sides are in place you are ready to add your head and tail blocks. Put glue on curved side of tail block, line up center lines with a small clamp, add a large clamp securing and squeezing the tail block to the sides and two cam clamps at top (one on both sides of the small clamp) to totally secure block to sides. Repeat for the head block. Let cure at least a half an hour.

Marking the tops and backs:

1. Take the top and back, take your plexiglas pattern and center it on your center line (so important!) and put a pencil in a router bearing and drawing around pattern creating an outline that is 1/4" wider than the original uke shape. Also, mark where the soundhole should be on the top.

2. Take to the bandsaw and cut out your back and top on the pencil line.

Now for the rosette:

1. Position of rosette is marked on the soundboard, in this case the salvaged fir. Width is measured from the choice of material for the rosette. In this case I have chosen 1/8" abalone with 2 black strips on either side. Pick out cutter that will cut that width dimension. Mike uses the drill press and a cutter he built himself. He used a plexiglas circle on the bottom to get a nice crisp edge after cutting. The Plexiglas did burn the top of the plate though which he reassures me will come out after putting through the drum sander.

2. I next inlayed the rosette by adding the outside black line first, a piece of 1/8" wide curved abalone strip sandwiched in with the start of the other inside black strip. I went counter-clockwise fitting in the abalone little by little, a little tap here, a little sanding there. If you have had any experience with inlaying you know no matter how exact you are with cutting the channel, the abalone can be off by a little bit and you have to do what you can to make it fit. After you've got it all in a thin super glue is applied all over the top of the rosette and then a spray of accelerator after that and in just a minute it is taken to the drum sander. See the glued rosette picture up top.

Well, we ran into some trouble. The abalone I had inlaid was a laminate abalone. We knew it needed to be flush with the top in order to keep the color but maybe because the top wasn't exactly flat the nice blue abalone got sanded out. :( Oh well, no problem. Mike just took it back over to the drill press and routed the channel out again. But now we are done for the day so a new rosette will have to wait. Until next time.

As you can see i'm having a little trouble with this blog as far as adding the pictures. I wanted to have a running detail in pics as far as the how the process goes but can't figure out how to add more than 5 pictures. If you have trouble understanding something leave me a comment and I will get back to you. Thanks for the look!

Picking out wood, joining the plates and bending the sides

Today Mike picked out some nice Ziricote for the backs and sides. I really like this nice dark highly-patterned wood. It’s going to be especially dramatic with the lighter sapwood running down the center. Dido for the sides, he picked out some nice Ziricote sides with the same sapwood that will be at the tail-end of the uke. I saw one of Mike’s uke’s on his gallery page and was especially attracted to an uke he had made (#034, if you go to his web page, http://ukemaker.com/), it is Ziricote back and sides and is teamed up with a salvaged fir top. I prefer this nice warm color to go with the dark Ziricote instead of say maybe a Spruce top.

Book match tops and backs then run through a jointer. Two matching halves are lined up together and set into a shooting board where they are hand-planed to get that nice tight seam. No light should show through the seam. They are then ready to glue up.

Halves are laid side by side with one side angled up. Binding tape is used to put across pieces. This tape stretches so when the glue is applied you can snap down the sides flat and that is all the clamping that is needed to hold these two halves together. Mike likes to use epoxy glue for this center seam. I love this trick! I was doing it a much harder way with less than desired results. Don’t forget to put a strip of wax paper under the seam before gluing and one on top after gluing. After that add plenty of weight and you are good to go. This glue fully cures in 24 hours. So, we will let this sit and move onto bending the sides.

I already had my own side bender so we are using it since it corresponds to my pattern shape. Recently, I was trying to bend some Koa and was not watching and burnt one of the sides! Mike showed me how to read the temperature of the heat blanket with a laser thermometer. I had never seen one of these. You just point it at whatever you need to know what the temperature is and voila! You have it. The temperature of the blanket should not go over about 300 degrees Fahrenheit. He also told me I need to get a controller hooked up in line with my blanket so you have full control of the temperature and can simply raise or lower it by turning a knob. Previously, I was just plugging it in and hope for the best. He also mentioned that the way I was doing it is definitely a fire hazard if one accidentally forgot to turn off the blanket! Good point. He also has a controller in line with his blanket that will automatically shut off after so many minutes.

Both sides, with good side up are placed on top of the bender sandwiched between sheets of 22-24 gauge stainless steel. The metal distributes the heat evenly to the sides while bending. First the waist is bent, then the upper bout and lastly the lower bout. The sides will be left in the bender overnight.

Making the Mold

Mike showed me how to make a mold out of any shape you might like your uke to be. I had a Tenor ukulele plan from Hana Lima Ia’ and had shrunk it down to a Concert size. So, we are going to use that pattern.

1. ¼” thick Plexiglas is cut on the band saw. Allow approximately 2” on each side (just the top and bottom and one long side) of the ukulele shape. The other long side is the center line and goes right up to the center line on your pattern. Joint one edge (this is the center line).

2. Line up the center line edge of Plexiglas sheet to center line of pattern and with a felt tip pen carefully draw half of the outline shape onto Plexiglas. You are only looking at half of the ukulele shape with the Plexiglas.

3. Cut out most of the uke shape with the band saw and then fine tune the line with a belt-sander. Keep checking shape to make sure it is what you want. Be sure to look carefully for any flat spots you might want rounder.

4. Take a sheet of ¾” Baltic Birch plywood and cut four pieces. The width of the wood will be cut as the same width you just cut the Plexiglas with. Joint one long edge of each piece. These 4 pieces of Birch can be jointed together. Again, this will be the center line of the mold. Now, sand edges with the belt-sander.

5. Drill holes into the Plexiglas with a countersink pilot bit. Screw Plexiglas template (with 1 ¼” #8x screws) onto one of the four pieces of plywood. Make sure the top edges are flush. Cut out the excess wood (uke shape) with a band saw and finish up with router to trim the rest of the wood. The Plexiglas template with a bearing on the router will make the exact cut of the pattern into the wood. All four plywood pieces are done this way.

6. Match up two of the wood sides and put into a vice making sure they go together perfectly. You can tap one side with a hammer to get it exact. Be sure to make sure center lines and tail and head block areas are perfectly matched up. These are screwed together with same screws (3-1 ¼” #8x). The other two pieces of wood are done in the same way. We now have two pieces of Baltic Birch that are 1 ½” thick for our mold.

7. Now place the two halves together in a vice. You will cut two scraps of wood approximately 1 ½” x 6” and attached one to the top of the mold and one to the bottom with the same size screws. Voila! You are now finished with the outside where the side of the uke will sit in. We now need to make the inside clamp which will hold the sides to the shape of the mold.

8. Take a turn buckle and hacksaw off the loops on the ends. Get two scraps of wood and trace the curvature of the uke pattern waist on one block. This shape is cut out on the band saw. Trace the line from the previous cut scrap of wood onto the second and cut that out. Find the center of each block and on its flat face drill a hole into each block that will correspond to the screw of the turnbuckle. The screw on one side of the turnbuckle is screwed into the hole of one block and the other side of the turn buckle is screwed into the other block creating the pressure to hold the sides of the ukulele in place in the mold.

9. Mike then took the mold over to the drum sander and ran it through to make it nice and smooth.

10. He then made me an inside template (just a piece of Plexiglas the shape of half an ukulele). He showed me how to mark it by cutting into the template with a saw to mark the center of the soundhole, brace locations, saddle position and the best was how to mark a ¼” all around the template with a router guide with a pencil stuck in it. How clever!

Starting Class

Hi, I'm Toni. And I'm just starting a class to build a concert ukulele with Master Luthier Michael DaSilva. If you haven't heard Mike makes some of the most awesome ukes in the world. I've seen many a uke but Mike's are in another class all by themselves. They are incredibly light-weight and for their size surprisingly loud! I knew after just holding one and then playing it that I needed to fine-tune (pun intended) my luthier skills.

A few years ago I got the chance to take an ukulele building class in Honolulu, Hawaii from Hana Lima I'a. There, with 5 other students we learned the "Spanish Style" construction. Now, I am ready to take my training to a new level. So, lets do it!