Kohei Fujii Guitars

Kohei Fujii Guitars

Sunday, December 31, 2017

Side assembly

     Side materials are vended and laminated. Sides are made from King wood and Yellow ceder laminate. Blocks for neck, tail and cut-a-way portions are made by Spanish ceder. My block is always made by recycled and salvaged ceder from my previous built. I glue together from small pieces to make large enough for block making. Cut-a-way design needs extra caution for assembly to make all parts are precisely assembled. Neck block also needs extra care to make precise curves for the neck and cut-a-way portion.
     The year 2017 is almost over. Thank you so much for subscribing this blog. I will continue this Juzz nylon model making the year 2018. Please stay tuned this page.








Sunday, December 10, 2017

Back making

     This week, I made the back. Material is the King wood from Mexico. King wood is one of the Dalbergia family. This wood has closed tonal resemblance to the Dalbergia nigra. I have couple of sets of the King wood. I jointed and applied the latticed bracing as my standard design. Lattice bracing material is the Adirondack spruce. This time, I thinned the King wood to 2mm which is pretty thin profile for the back to minimize the guitar weight.
     Next week, I will make sides using the King wood with the Yellow ceder laminate.

Sunday, December 3, 2017

Carbon Latticed and X-bracing

I created a new bracing pattern for my Jazz Nylon model. I want to increase more over tones. To make more over tones, I introduced ax X-bracing technique. I want to make more structurally strong in the upper bout section. Lattice bracing top does not have enough mechanical support for the top against the strings pull. Therefore, Greg Small-man type guitars have been using a massive play-wood based flame for the top as shown in the first photo. The massive flame makes super strong top. This flame also is able to support the super thin latticed top. As a result, this guitar design makes super laud sound with full over tones. I do not want to increase guitar weight. Therefore, I introduced the X-bracing technique. X-bracing has been using for the Nylon strings guitars for many builders. Martin guitar is the most famous builder. However, Martin's Nylon strings guitars have not been successful as the steel-string guitars. Martin has been using almost identical X-bracing pattern designed for steel strings guitars. Therefore, the Martin's X-bracing pattern is simply over built.
Paulino Bernabe has been using the X-bracing pattern. His guitar has exceptionally good tonal quality. A photo shown below is the Bernabe guitar, and you may see that the guitar has the X-bracing pattern. His X-bracing has quite wide angle to make the optimum resonance modes for Nylon strings guitars.
I borrowed Bernabe's X-bracing ides for Nylon strings guitars. However, my X-bracing design has more steel strings influences, because I have been making X-bracing for my steel strings guitars. My X-bracing has almost triangle cross section to make the strongest possible structure with the lightest possible weight. Also, my design has the sound hole supporting bars. Those bars contributes to increase the robustness in the upper bout. I also will install two carbon rods shown in below to improve the structural robustness.
Following photos are my new bracing pattern. I installed the 8x8 balsa lattice, and then I did the Epoxy Carbon vacuum laminate. This lattice construction is pretty much the same as the Small-man design.
 X-bracing materials were cut from Adirondack spruce logs. I have been using the Adirondack spruce for my brace making for my all guitars. Adirondack is one of the strongest material among spruce species available for guitar making.
 Those photos are completed top for the next Jazz nylon built. I am very excited about using this top. Top wood is the Lutz spruce that is a hybrid between Sitka spruce and Engelmann spruce.



Sunday, November 19, 2017

New Jazz Nylon Built Start

I start a new built using the Lutz spruce top. This is a Jazz Nylon model. I completed the Rosetta making. This time, I used Padauk, King wood, Tamarind, and Ebony. This is the first time to use the Padauk. I wanted to introduce nice red for my guitar. I am very excited to adding more color in my guitar design.




Sunday, October 8, 2017

Offset sound hole lid making

I made off-set sound hole lids. Those lids are designed for stage performances with other instruments such as bass, drams, and vocals. In stage performance, feedback related oscillation issues are quite common. This lid is able to minimize the issue, because the acoustic chamber (guitar body) reacts much less responsible with no sound hole. With this optional lid, the Jazz Nylon model improved significantly for set-up difficulty for stage performances.





Sunday, August 27, 2017

Juzz Nylon Complete

Jazz Nylon model is completed. I played using D'Addario Pro Arte Ej46 strings. This guitar showed excellent and very loud sound since beginning. I was so surprised with full of over tones. In this built, I employed the Carbon Epoxy composite technique using the balsa lattice design. Carbon Epoxy composite configuration made a real differentiation. I am vary happy with this result. This configuration makes very dry and metallic sound with full of over tones. So the sound character is different from traditional nylon string guitars. I will show this guitar in the La Guitarra California festival in between September 22 and 23. Please come and check it out.

http://www.laguitarracalifornia.com/





Sunday, August 6, 2017

Final Corting

Jazz nylon model was completed pore filling and final coring works. Filling work has been done by Epoxy and Silica thickener combination. Honduran RW has large pours, and it required three filling and sanding sessions. After complete the sanding sessions, I applied Alcohol thinned Epoxy except top for making even color. Then, I stained the top as Yellow. After completed the staining, I applied four layers of EM6000 finish. Next morning, I had a 1200-grit sanding session. Then, I applied additional three layers of EM6000. Jazz Nylon will sit at least next 10-days for curing the finish.