Tulipwood Concert Ukulele Build blog:
October 18 2021
I am starting a spruce and tulipwood concert ukulele for a friend. It may be a little bit fancy for me as she is really in to having a shell rosette and purflings. I always thought tulipwood was poplar and rather plain. This wood is figured with good tonal properties. After helping someone on line with some plans, I was sent the set. Maybe some one recognizes this wood. (I have since learned that this is, DALBERGIA DECIPULARIS ORIGIN: SOUTH AMERICA. A true rosewood.
Tulipwood is an exotic wood native to the tropical region of South America, mainly Brazil. It is a hard and heavy wood, with a rather fine texture. The sapwood is a solid yellow color, while the heartwood color ranges from a pink to a darker red, with a straw colored background. Tulipwood is excellent for wood turning, as well as knife handles, furniture, and cabinets. It is a lustrous wood, has excellent polishing qualities, and glues well.
I have never made a concert before, I once bought a complete set of Martin Ukulele forms at an auction so I was some what ready. I got a mold from John Hall modified it and combined it with a work board for a Spanish neck joint. In the background you will see I have a second mold that I will use if I ever do a bolt on.
I used an old record plane to joint the plates. I used my guitar plate jointing jig to clamp the plates together but it really was too big.
Here is most of the tonewood I will use. A couple of years ago I accidently rift sawed large mahogany neck blank. I also had a nice plate of ebony, so I used two rift saw mahogany pieces and the ebony to mack a neck blank. I will need some thin wings for the head stock to get enough width.
I used my bandsaw to profile the top and the back.
I installed a Paua Abalone rosette with black fiber purflings. I used my bishop cochren router base to to cut a 1/16" + 1 mm channel. I carefully set the diameter of the rosette using a set of calipers. I am using a 1/16" bit. I cut to the inside line, make the diameter 1 mm larger and cut for the purfling. I use a bit of the shell to set the depth.
Once routed I tested it and ultimately made it a smidge wider to deal with swelling from the glue.
Once the glue set I leveled the fiber strips and cleaned out (well sort of cleaned out) the channel
Then I just worked my way around breaking the abolone into the channel. I would start at one end jam as much as I could along the channel until the strip broke. I would use that pointy tool to push in the piece and once in, push back tight against the previous piece and repeat. I used thin CA to set the shell as I went. The spruce was sealed with the purfling and the glue I used to install the purfling.
used the same bit to cut out the sound hole. I set the bit depth a little more than my final top thickness. I sanded the back of the top until the sound hole dropped out.
October 20 2021
I got a little done yesterday and I may have a bit more time this afternoon.
I profiled, thicknessed and bent the sides for the rims.
My eyes are not what they once were, so instead of penciling in the profile lines I just taped on the template. Really easy to follow, with careful placement of the waist, I ended up with perfectly book matched and profiled sides.
To keep the book match through sanding I marked it on the side of the sides. I sanded to .080" as that is the thickness of the blade I use to cut the heel slots. Also a good thickness to bend. On a bolt on I might go as low as .070" for a ukulele.
I use a John Hall ukulele side bender from [url=https://bluescreekguitars.com/product/ukulele-side-bending-machine/]Blues Creek Guitars[/url]. At an [url=https://www.asiartisans.org/content/]ASIA[/url] auction I bought at a very good price a complete set of ukulele bending forms and molds that John Hall donated.
I used just a sprits of water and paper towel, I starting with the waist at 225°F I bent the waist most of the way, lower bout then upper bout and a tightening of the waist. I set the temp at 280°F and let it set for 12 minutes.
After cooling I removed it from the side bender with very little spring back. What ever this wood is it is really easy to work with.
With both sides bent, I used the molds center lines to mark one of the sides. I cut close on the bandsaw and finished on my belt sander. With the one side trimmed I used it to mark the other side. I cut the second side a little long and touch fit on the belt sander until it fits in the mold.
With the sides trimmed I rough profiled the neck and used my special purpose sled to cut the slots.
I trimmed the heel side of the sides back 5 mm and fit it all into my new work board and mold.
October 23 2021
I have mostly been doing website maintenance the last few days, but I did get a bit of time on the rims and clean up the neck a bit.
Before I get ahead of myself and glue the rims to the neck I decided to do a bit more work on it. I use a safe T planer for both the head stock and the taper of the neck. I shim up the nut side of the neck to give me the thickness. I have measurements for the 1st and 7th fret of 11 mm and 12.5 mm respectively. As shown in the first picture the distance between the 2 frets is 105 mm, the distance from the 1st fret to the end of the neck 200 mm. So I calculated the slope of the taper rise/run and determined a shim height needed when pivoting on the end of the neck by taking the 200 mm multiplied by the slope. So 2.88 mm. I glued the shim right on the 1st fret location.
Then I planed away with the safe-T planer where I could until I had my desired thickness.
I also made a few passes on the head stock to get close. I need the veneer to do the final thickness. I left a thick area around the nut to give me options for the transitions between the neck and the head stock.
I made some wings for the headstock with some cutoff from the original neck blank.
I really hate routing out the end graft late in the building process, so I generally glue it to the tail block and then glue the sides to the tail block. If I am careful and get the end graph on square it is really easy to glue the sides to block one at a time and still have the rims square. Pictures show it better.
First I use a machinist square to glue on the end graft square.
I use my belt sander to cleanly take off half of the end graft from each side. I scratch a line. Make sure the top is down as it is square to the center line
One side then the other and done!