I have been nervously waiting but I can not rush the finish process. I used zpoxy - EM6000 wb finish on the body and CA and Royal Lac on the neck. I am just a couple of days from being able to sand and buff out the guitar.
July 29th 2016
It still needs a setup and the final polishing, but here it is with strings. The top resonance came out lower than I thought at 175Hz but the bridge rotation while not measured looks OK. The height of the two main falcate braces were at 10.5 mm around the bridge; 3.5 mm higher than might last SS that ended up with a 170 Hz top resonance. As a further note I used the same vibrational stiffness value in Gore\Gilet equ. 4.5-7 and the secondary braces were kept the same at 7 mm. The back may be at 233 Hz, the back was heavy so I did not brace it as an active back.
If it holds together it has a very loud and rich sound.
I built this as a commission, although I told the client that it was an experimental build as it was my first 12 string. I did use a lot of information from the Gore\Gilet books including the bracing pattern and bolt on\off neck design. The body is the Gore medium size steel string. I followed a tutorial from Craig Lawrence on the Australian\New Zealand Luthiers Forum for the 2 string per pin bridge. Richard Woods (Woodsy23 on also on anzlf) modified and ran an existing Finite Element (FE) model he had, for 12 strings load, both light and medium (EJ38s and EJ39s). He determined I would need to increase the height of the falcate braces to 10 mm for the EJ38s and 11 mm for the EJ39s. I ended up with 10.5 mm as I wanted to limit the monopole frequency of the top to keep it in the typical SS range. I ended with 175 Hz top frequency (that I may work to lower to 170 Hz). I have a spectrum analysis with strings at the bottom of this post. I did not measure the bridge rotation under load, but it looks good to my eyes.
The top is Lutz Spruce, back and sides Ziricote.
Bridge BRW, Fretboard EIR, Ebony bindings
rosette, Headstock, backstrap, end wedge, heel cap and side purfling are all Koa.
Finish: EM6000 on zpoxy fill for the body and CA fill and Royal Lac for the neck and head stock.
The new owner came by my house to pick it up. He really liked the guitar and played it for me and my wife for about an hour. It is fun to build a guitar for a real player.
He left a nice note on his facebook page as well.
Yesterday, I become the proud and happy owner of a beautiful hand crafted, custom made 12th string guitar by the talented John Parchem. I am so fortune that John took on the challenge to build this fantastic guitar for me. Besides for producing great sound, this guitar is an authentic piece of art that I will cherish forever! -- Without doubt, my must valuable piece in my guitar collection -- Thank you very much John!!
Like all good engineers :) John has captured the journey and the effort that took to build this unique guitar on this website -- Highly recommended! While there, check out also the other great instruments that John has crafted throughout the years.
-- Finally, next time when I play Led Zeppelin’s Over the Hills and Far Away it will "short of" sound like when was recorded :)