Saturday, August 28, 2010

Notable Firsts

This is a guitar project I've had very little time to work on lately, but with the Australian blackwood/Sitka spruce triple-O featured in my last post about to head off to its new home, I delude myself with the notion that with one less guitar to complete, this East Indian rosewood/Engelmann spruce effort is somehow closer to completion too.



With a side soundport and a Florentine cutaway, there are some personal firsts for me with this instrument. This has also been my first experience using Grafted Coatings' "other" water-based finish, KTM-SV, which I've written enthusiastically about in earlier posts. KTM9, Grafted Coatings' previous foray into water-based finishes, was successful up to a point and still has its advocates, but there have been enough negative reports over the years that I eventually discounted it as I considered a switch to sprayed finishes. I think it's fair to say that in many people's experience it hasn't stood up well to normal wear and tear or, most alarmingly, to the corrosive effects of some people's perspiration. To date, I've read no reports of a similar nature regarding KTM-SV - fingers firmly crossed!


The soundport is an increasingly popular feature and proved a simple addition, which perhaps accounts for the fact that some professional builders offer it as an option at no additional cost. Adding the port is a relatively easy task which I completed once kerfed linings had been glued around the rim and the back had been attached to the sides. The guitar sides diminish gradually in depth as they approach the neck area, and it was easy to glue in a similarly tapered veneer laminate to wedge snugly between the linings as cross-grain support in the area of the port. I chose a simple oval soundport which was marked on the outer face of the side with the aid of a flexible plastic template and a white ball-point pen. I used my Dremel and a tiny circular saw blade to roughly cut through the side and the backing laminate well inside the line, then sanded to the line with the Dremel and a mini sanding drum.


The cutaway presented a more formidable challenge, with much head-scratching and several sleepless nights required before a plan of attack was formulated. Bending the cutaway section of the side on an electric bending iron was easy enough, but binding the point of the cutaway proved a little trickier; I chose the ambitious approach which was to mitre the joints in three dimensions. The outcome wasn't perfect, but having now negotiated the process more or less successfully, I can see ways to improve the end result next time around. Generally, it's only after I've addressed a problem and found myself unable to identify a potential solution that I become temporarily dejected and briefly contemplate other less taxing hobbies!

Cheers
Pete

Friday, July 16, 2010

Reaching the Finish Line - KTM-SV

I've made significant advances with many aspects of guitar construction in the recent past, but achieving a quality finish has proven to be a persistent frustration as well as one of the last major hurdles. It's especially pleasing then to be able to report that the finish used on this guitar - Grafted Coatings' KTM-SV - has proven to be a watershed where confidence in the standard of my guitars is concerned.


While there's still plenty of scope for further improvement of my skills and knowledge - most noticeably in the area of fretwork and setup - I'm quietly confident that my guitars are approaching a standard comparable to that of other fledgling independent builders. If I ever make the leap and decide I'm ready to sell my guitars, the prices I ask will of course reflect this cautious assessment!




Finding a finish product which works for me is cause for celebration, but rubbing it out to the high gloss that guitar owners expect has been yet another challenge. Thankfully, after taking the plunge recently and ordering a buffing arbor from LMI in the US, I'm pleased at last to be able to bid farewell to the more laborious hand-polishing methods. Not only was it an onerous task, but I was never entirely satisfied with the end result. With motor-driven buffing wheels and two grades of Menzerna dry buffing compounds at my disposal, the process is an absolute breeze and the gloss I'm now able to achieve reduces the pain of having purchased a hefty piece of equipment from overseas. International freight charges - as always - are a real headache!


I guess some vital statistics are in order:
  • Back and sides: Australian blackwood
  • Soundboard: Sitka spruce
  • Neck: Queensland maple
  • Bridge and fingerboard: ebony
  • Bindings: ebony
  • Frets: EVO gold
  • Tuners: Gotoh 510 minis
  • Rosette and fingerboard inlay: paua abalone
  • Finish: Grafted Coatings KTM-SV
  • Scale length: 24.9"

Click any of the photos for a larger view.

Cheers
Pete

Thursday, March 4, 2010

Double-Standards


What a strange set of standards we apply when it comes to wood. Where backs and sides and, to a lesser extent, soundboards are concerned, we are happy to pay a premium for colourful, unique or highly-figured woods. According to tradition though, components made from ebony must be jet black and are graded and priced accordingly. We can even buy dyes especially for the purpose of reducing interesting, streaky ebony to a boring, homogeneous black!

The ebony headplate pictured was rated as "second-grade" material, presumably because it wasn't boring enough. Make up your own mind!

I've applied a first seal coat of shellac on this neck and will spray another two before allowing it to cure overnight. Once the finish coats of KTM-SV have been sprayed, levelled and polished, I'm confident this ebony will look much better than second-grade!

Cheers
Pete

Thursday, January 14, 2010

In Pursuit of a Glossy Finish


Without access to a buffing wheel, it's a case of gritting my teeth and rubbing out the finish on this guitar using more tedious methods. It's a good workout if nothing else!


I was careful to level the finish thoroughly as the spraying of the 12 top-coats proceeded. As a result, it was a relatively easy task to carry out the final levelling with 800-grit wet-or-dry paper and water once the finish had been allowed to cure for a few days. To allow for the curvature of the guitar's surfaces - including the domed top and back plates - I wrap my abrasive paper around a small rectangle of cork floor tile. The cork provides a solid backing for the paper but has just enough flex to conform to the curves. I've had better results since I began sanding with the grain, the significance of which is that by sanding in one direction, the sanding scratches seem more easily removed by the grade of paper to follow.



Other water-based finish products require that mineral spirits (turpentine) be used when wet sanding, however, I detest turpentine for any application and it's a blessing that KTM-SV can be safely wet-sanded using water as the lubricant, - the proviso being that it's been given time to cure. It's become very clear to me that a little extra time spent sanding thoroughly through 800, 1200, 1500 and 2000 grit papers to remove sanding scratches before the polishing compounds are brought into play makes a high gloss much, much easier to achieve. If you noticed the large gap between 800 and 1200, it's only because my usual local sources seem to have run out of 1000-grit paper temporarily. Sanding is a tedious task, but I found that reaching for the polishing compounds too soon invariably saw me return to wet-sanding soon afterwards when polishing revealed remnant sanding scratches - there are NO short-cuts!


As I mentioned in an earlier post, I use Autoglym's 03B Fine Abrasive and 02B Ultrafine Renovator once I'm done with sanding. With limited experience with sprayed finishes, I'm still pretty tentative when it comes to levelling and polishing for fear of rubbing through the layers of finish to the wood and, although a random-orbital sander equipped with hook-and-loop Surbuf pads helps with the polishing to a degree, I've been careful to stay away from the perimeter of the guitar's top and back plates as well as the edge of the soundhole, the area of the side soundport and the cutaway region while using it. As a result, I'm left with the option of a cork-backed sanding block wrapped with a polishing cloth to rub out these areas. It's not a difficult job, but patience and persistence are valuable assets - ones I wish I had in greater measure!


Click on any of the photos for a larger view.

Cheers
Pete

Thursday, December 31, 2009

Beautiful Blackwood

Here are a couple of attempts to show the beauty of Australian Blackwood after I sprayed two coats of de-waxed white shellac this afternoon as a sealer and tie-coat.




Among the many significant milestones to be enjoyed during the building process, this must surely be one of the most satisfying - the ugly duckling is turning into a beautiful swan! There's still a long way to go before the transformation is complete, but it's at this point I tell myself I can see the light at the end of the tunnel and can look ahead eagerly to the end result of my latest collaboration with Mother Nature.

I visited Australia's south-east for the first time last year and was taken aback by just how common Australian blackwood (Acacia melanoxylon) is, however, trees yielding wood with the striking figure displayed here are altogether more unusual. The rippled appearance in the grain changes constantly depending on the direction of the light and the angle of view - no photograph can truly do this wood justice! There's little wonder it's become so highly prized in the guitar world both here and abroad for it's looks alone.

Just to demonstrate that its popularity extends beyond guitar enthusiasts, here's a shot of a brushtailed possum who had taken up residence in a blackwood tree next to our overnight camp in Victoria's Tarra-Bulga National Park.




Click on any of the photos for a larger view.

Cheers
Pete

Saturday, December 26, 2009

Economies of Scale

As my current marathon effort building several instruments at the same time draws to a conclusion, I've sworn never to repeat the exercise when I finally have a clean slate and I'm ready to begin the next one. As a part-timer, the building process is slow enough as it is and I've found it a little frustrating having to wait so long to enjoy the fruits of my labour when my limited time is divided between so many instruments.


Nevertheless, it's sometimes more efficient to work on a production run of components like these mahogany neck blocks, when preparing bracing stock or dimensioning and slotting the mahogany strips to be used as kerfed linings. The additional time involved isn't hugely significant and it's easier to fabricate them mindlessly with consistent dimensions when jigs are in place or machinery is set up and adjusted appropriately. There's the pleasing illusion of rapid progress to be enjoyed later on too when there's a ready-made stock of components on hand!

Cheers
Pete

Saturday, December 12, 2009

New Rosewood Back and Sides


Here's a recent acquisition which I hope to begin work on early next year, assuming I've managed to complete my current crop of guitars. As much as I've grown to love it, East Indian Rosewood can sometimes look a little bland and uninteresting, but in this case the colour variation is a little more pronounced than usual and I found myself unable to resist the urge to click the "Buy Now" button when I spied it on Allied Lutherie's web site! It should look terrific under a finish, and the tap-tone in its current raw state suggests that it has the potential to sound pretty impressive too.

East Indian Rosewood is something of a staple in the guitar-building world and, unlike some of the other rosewoods, is still reasonably priced and has a fairly secure future. I always smile when I see sets of this wood marked down to a lower grade when they're not exactly quarter-sawn or exhibit anything less than perfectly straight grain. Some of the other more coveted rosewood species are offered to instrument builders for astronomical prices even when they're flat-sawn or have been salvaged from stumps and have the wildest grain imaginable. The bar is obviously set pretty high for their Indian cousin!

Cheers
Pete


What's In a Name?

The back and sides of this guitar are of narra, which is an alternative name for a wood that's most often marketed here in Australia as ...