Sunday, March 31, 2013

The Fingerstyle Guitar - Epoxy Pore Fill

While it's perhaps not in the same league as the Claro Walnut used on the guitar I've recently finished, applying the first coat of epoxy pore fill to the instrument pictured reminds me that each piece of wood has its very own character and unique appeal. Once again, walnut has cast its spell over me and I'm very pleased with the way this guitar is shaping up.


It's an unfamiliar feeling to be pore-filling an instrument so soon after completing the previous one. Typically, many months pass after finishing an instrument before I'm ready to repeat the process, but as I work my way through this current batch of three guitars, I'm no sooner finished with one part of the process than I'm ready to repeat it on the next guitar.

With the necessity of a day job to distract me, the prospect of spraying the finish coats presents something of a problem: to apply the necessary number of coats to the back, sides and neck, I need to devote three consecutive days to the task if I'm to limit the number of coats per day to five. As I'm employed on a contract basis and paid by the hour, the bad news is that I'll need to sacrifice a day's pay if I'm to successfully apply a sprayed finish to the guitar - all the more reason to begin selling my instruments!

Cheers
Pete

Friday, March 29, 2013

The Fingerstyle Guitar - I Can Smell the Finish Line!

After a few days' break from guitar building during which I've enjoyed noodling on Tiani's Claro Walnut /Sitka Spruce 000, it's time to get back to the workbench.


I delude myself with the notion that this Claro Walnut/Redwood OM is essentially complete, ignoring the fact - because it pleases me to - that the lengthy process of filling, finishing and buffing lies ahead of me. After a solid day's work installing the remainder of the purfling and bindings, a few hours' final sanding sees me ready to apply epoxy pore fill to the back, sides and neck. The walnut back and sides are not as spectacular as those of the 000 I've just finished, but there's enough subtle flame evident that I'm confident the final package will look pretty slick - the Macassar Ebony and Zebrano components almost guarantee it.




Cheers
Pete 

Saturday, March 23, 2013

Sunday, March 17, 2013

Claro Walnut/Sitka Spruce 000

I was finally able to string up this guitar yesterday, and I look forward with some excitement to presenting it to Tiani, its new owner.

Tiani is the talented daughter of a family friend, and her youthful passion for music is truly refreshing. Although her musical inclinations have little in common with those of the players I imagine myself building for in the future, she's nevertheless a worthy recipient of this instrument on the strength of her originality and enthusiasm alone.


I began this guitar three or four years ago, and at some point over the course of its construction the decision was made to donate it to someone I felt could put it to better use than I could. There were some minor cosmetic blemishes that irked me, but more significantly, after the box was closed up and remedial work became impractical, I was concerned that the top was braced too heavily. As a result, I had serious doubts about its likely success from a tonal perspective and it took a back seat to other guitar projects for a couple of years. With that as a background, I was prepared to be less than impressed yesterday when I strung it up for the first time, and my initial assessment was indeed less than enthusiastic. However, after only a few hours, I was much less critical; in the absence of any other explanation, I suspect the strings simply needed to be left in peace for a short time to acclimatise to their new home: bent over saddle and nut and brought up to concert pitch. It's early days still, but I'm prepared to cautiously pronounce the guitar a success - I hope Tiani feels the same way!


I'll let the guitar settle further over the week ahead, make final adjustments to neck relief and action height, and hopefully hand the guitar over to Tiani soon afterwards.

Vital statistics:
Back and sides: Claro Walnut
Soundboard: Sitka Spruce
Neck: Tarzali Silkwood
Fretboard and bridge: ebony
Bindings: curly maple
Scale length: 24.9"
Finish: Grafted Coatings KTM-SV
Pickup: K & K Pure Mini

Cheers
Pete

Saturday, March 9, 2013

KTM-SV - Sanding and Buffing

There are a multitude of guitar finish products available, and it's generally acknowledged that each of them have their advantages as well as their shortcomings. The dilemma for the guitar builder, then, is in deciding which particular compromise they can live with, and what product best suits their particular circumstances.

My current choice is Grafted Coatings' KTM-SV, a water-based, oil-modified urethane that a growing number of musical instrument makers are using with great success. I'm in the throes of completing the guitar pictured - my third using KTM-SV. Although I've been pleased with this product so far, if a little of its flexibility could be sacrificed for the sake of hardness, I'd be truly ecstatic. I'm keeping an eye out for the release of the manufacturer's new product - which I believe will be marketed as KTM-10 - in the hope that it makes up for what KTM-SV lacks in terms of hardness. Early reports sound very encouraging.


My technique with the spray gun tends to improve over the course of finishing a guitar, and by the time I've applied the last of the top coats, I've generally sorted myself and the gun out to the extent that the guitar's finish is level and reasonably smooth. After the finish has cured for a few days, the process of sanding through the grades of sandpaper can proceed. With the paper wrapped around a cork block, I begin sanding with 600 or 800 grit paper, depending on the quality of my last coat. I'm pretty cautious when sanding the edges of the body and the headstock; I skip the coarser grades and begin my sanding of those areas with 1200 grit paper, dispensing with the sanding block. I use soapy water as a lubricant throughout this process, and constantly check my progress by squeegeeing off the water and holding the body or neck up the the light to check for rogue sanding scratches.


Inevitably, I'll sand through the topmost finish coat to one or more of the underlying coats; witness lines are evidence of that, even after a thorough sanding with the finest of the papers. It's at this point, of course, that my attention turns to the buffing wheel, but I've learned that this finish needs a couple of weeks to harden enough that buffing will completely remove these witness lines. I've wasted a lot of time and effort and become quite frustrated when attempting to achieve a mirror-like gloss before the finish has had time to harden - it's just not going to happen! Not unexpectedly, it's also apparent that the finish shrinks ever so slightly over the first few weeks. On future guitars, I plan to delay sanding with 1500 and 2000 grit papers - if not all of them - until a couple of weeks has elapsed and I'm about to buff. Perhaps that's not so much of a consideration where the soundboard is concerned as ridges in the finish corresponding to grain lines seem to be accepted, given their inevitability when any of the more traditional nitrocellulose lacquers are used.

Links to Grafted Coatings' web site:
KTM-SV
KTM-10

To view previous posts dealing with KTM-SV, click here.

Cheers
Pete

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