Irish Bouzouki - The Rosette

I managed to complete the rosette this morning. There's no hint of chipping which has frustrated me in the past, thanks to a tip I picked up from a long-forgotten source.

Prior to routing the inner and outer purfling channels that border the rosette, which I complete after the inner tiles have been glued in place, I applied Titebond to the soundboard in the immediate vicinity of the rings and let it dry overnight. The rationale for doing so is that the wood fibres of the soundboard are less likely to tear or chip when the channels are routed as they are supported and stabilised by the glue. I believe the original suggestion involved the application of shellac in the vicinity of the rosette, but as I'd already managed to smear some Titebond on the soundboard when gluing the inner tiles, I figured it would achieve the same goal. Mission accomplished!

Cheers
Pete

Irish Bouzouki - Fun With Moulds

Making jigs and moulds is a messy and time-consuming affair. There are definitely more enjoyable ways to spend one's time, so I figure it's worthwhile investing a little extra effort and expense to get it right the first time.

Half-body and full-body templates, with headstock template

While I wait for suitable weather and a break in my IT work long enough to afford me the opportunity to spray finish coats on the four guitars I've been constructing (seemingly forever!), I'm taking the first steps in building an Irish bouzouki - a first for me. After deliberating for some time where design and dimensions are concerned, fabrication of an outside body mould and templates for the bridge and headstock have been my focus in spare moments over the past couple of weeks.

Where construction of the body mould was concerned, my first task was to decide on the overall dimensions in the absence of any universal standards. In the guitar world, the iconic factory models manufactured by Martin and Gibson for many decades have at least served as a loose benchmark for the independent builder. However, as the Irish bouzouki was appropriated to a large extent from the Greek instrument and randomly modified to suit the requirements of a motley band of Irish folk musicians, its evolution appears to have been driven less by tradition than by the whims of the builders and musicians who have adopted it. It seems there are any number of combinations of scale length, body shape and body dimensions in common use, and I finally decided that in the absence of any agreed formula I'd develop something largely on what appeals to my aesthetic tastes. I was influenced a little too by the length of the truss rods I have on hand, my available fretting templates, and my concerns that an extreme scale length and a body join at the 17th fret - as is common practice - would result in a cumbersome, neck-heavy instrument. For better or worse, I've decided on a more conservative 632mm (24.9") scale length, a body width of ~350mm (14"), and a neck to body join at the 15th fret.

Using a set of French curves and a flexible ruler, I tidied up the half-body outline I'd drawn freehand on paper so that the curves transitioned and flowed smoothly. I traced the final outline onto a piece of baking paper, then transferred the outline to a piece of 6mm (1/4") MDF using transfer paper sourced from an art supplies shop.

I jig-sawed the MDF just inside the body outline I'd transferred from the tracing paper, then carefully removed the rest of the waste up to the line using a spindle sander. This yielded me a half-body template that would guarantee symmetry when used as a routing master. To fabricate the full-body master template, I aligned the centreline of the half-body template to a line I'd ruled on a second piece of 6mm MDF, traced the body outline and jig-sawed within the line, then clamped the two pieces together and routed to the line with a flush-cut router bit riding along the inner edge of the half-body template. Flipping the half-body template over and again carefully aligning the centrelines, I routed the other half in a similar fashion. The half-body and full-body templates are shown above.

I know from experience what a dusty mess MDF makes when machined, and of its tendency to deform and deteriorate over time, and made the decision to spend a little more money and fabricate the outside body mould from ply. To do so, I traced inside my full-body template onto a piece of 18mm ply, then jig-sawed inside the line leaving a small margin. Once again, having carefully aligned and clamped the full-body template in place, a flush-cut router bit removed the remaining waste.

I've struggled in the past to accurately align the individual layers when fabricating new moulds, and the solution - now that it's dawned on me - seems embarrassingly obvious. On the second layer of ply, I once again jig-sawed inside the pencilled body outline transferred from the full-body master template, then aligned and glued the two layers of ply together. It was then a matter of routing the waste to the line on the second layer of ply using the first layer itself as the bearing surface for the flush-cut router bit. The process was repeated for the third and fourth layers, with the final mould therefore comprised of four perfectly aligned layers of ply yielding a total thickness of 72mm.

Useful links:
Graham McDonald's, "The Bouzouki Book"
Nigel Forster Guitars - Irish bouzouki page

Cheers
Pete

New Year, New Opportunities

I'm not one for New Year resolutions, but given that January 1st can represent a fresh start if it suits us to view things that way, it seems like a good time to reflect on the year just passed, set a few loose goals for 2016, or at least anticipate the opportunities that the year ahead will present me with. First and foremost, I'm finally in a position to ease myself out of a full-time commitment to IT work and into a more relaxed work schedule that will include much more time at the workbench. That's a pretty good way to start the year, don't you think?

Due to a very kind offer from a friendly local, I now have a vastly more comfortable space in which to work, and it would be remiss of me not to acknowledge his generosity and thank him profusely. Thanks Neil!



To those of you who drop in from time to time to check out this blog, may your own 2016 be happy, healthy and filled with very good things.


Cheers
Pete

Workshop Dreaming

I guess "rustic" wasn't in the forefront of my mind when I envisaged my dream workshop, although I've always considered that its setting should ideally bring me close to nature. The primitive outbuilding at the rear of our temporary home will function as my workshop - hopefully in the short term - and actually allows nature into the workshop! Needless to say, I'm prepared for my resolve and my adaptability to be tested in the months ahead.

Our cottage is simple but comfortable, but to state that the structure at the rear of the property that will function as my workshop is basic is to take the concept of understatement to new levels. I can deal with the uneven dirt floor, but it's the "air-conditioning" that is likely to provide the main challenge. I've taken the precaution of attaching a hygrometer to the wall behind the workbench; my guitars and I can seek refuge in the cottage whenever the relative humidity creeps outside of what I consider to be safe limits. In a controlled environment, I try to maintain a relative humidity of 45%, so alarm bells go off in my head when I see the gauge drop much below 40%, or begin to rise above 60%.

To take a pragmatic approach, I'm confident that if I pay close attention to the ambient temperature and relative humidity, the standard of my workmanship won't suffer, although my personal comfort may be less than optimal at times. Having said that, when I eventually have that dream workshop, you can bet I'll appreciate it!

Cheers
Pete

Reality Check

The anticipation of moving east to the little village of Stanley in south-eastern Australia was difficult to deal with at times; for too long I've looked forward to devoting the majority of my working days to building guitars!

Reality has bitten though, and the prospect of building - or having built - a purpose-built workshop seems a little further away since the verdict of our appointed building inspector was delivered on the house Sandi and I inspected during our scouting trip a few months ago. The building inspector's findings were off-putting to say the least, but not entirely unexpected given that we're downsizing in a serious way, and looking at properties whose age and condition is reflected in their low price tag!

The little rental property we've selected as a temporary home is cosy enough, and is at least located in the village we've committed to settling into. However, storage and working space is in short supply and the prospect of commencing any new guitars seems like a distant dream. There is hope, however, when I reflect on the fact that the woodworking aspect of the guitars I have under construction is complete, and the process of applying finish to them is at least within my grasp - weather permitting. It's unseasonably warm and dry at present and with the relative humidity outside plummeting to the low twenties through the day, I'm wary of submitting guitar bodies to such conditions for any length of time. Hopefully, this spell of warm weather won't last and I can prepare to spray some finish top-coats soon.

Short-beaked echidna - a recent visitor to our garden.

Cheers

Pete

The Call of the East

Stanley, known variously over the years as Snake Gully or Nine Mile Creek, is a small village located in a historic gold-mining area in Australia's south-east. It's primarily a nut and fruit growing area these days, but is home to a number of artists, artisans and - rumour has it - an odd assortment of eccentrics. I'm pleased to announce that, together with my partner Sandi, I'll soon be leaving the west behind and joining their ranks!

Approaching Stanley from the south

Along with this impending cross-country move, a significant downsizing will afford me the opportunity to build guitars in a more-or-less full-time capacity. What's more, with no pressing need to maximise output and profits, I can be totally self-indulgent and devote as much time as necessary to improving my guitar building skills, perhaps even diversifying a little into mandolin and ukelele construction. Most importantly, I'm looking forward to settling in a small community of like-minded people, and developing a more laid back approach to life in general, far from the hustle and bustle of the city. The stars are brighter too!

Cheers

Pete

Positioning the Bridge

There are several handy gauges and gadgets available that help the guitar builder determine the position of the bridge, but the method I've adopted works well enough that I haven't felt the need to try them out. To give credit where it's due, I believe I first saw the method I'm about to describe on Matt Mustapick's now defunct and sorely missed workshop blog.

On this particular Port Orford Cedar soundboard, the grain is incredibly fine and the centre join is extremely difficult to detect. I've lightly pencilled a line along the join to highlight it, then taped a sheet of graph paper to the soundboard with the centre grid line aligned with the pencil line. With the neck securely attached, I measure from the nut end of the fret board and mark the notional scale length on the graph paper - it's the longer of the three marks in the picture below.

I make a second mark a little under four millimetres further along the centreline to allow adequately for compensation, acknowledging that with wider saddles gaining favour among many builders these days - myself included - there's plenty of scope for fine-tuning of intonation once the guitar is strung up.

I measure the distance from the centre of  the saddle slot to the front of the bridge at its mid-point, then measure back from the compensated mark on the paper towards the nut by the same distance, placing a third mark on the graph paper to represent the front edge of the bridge. I extend this mark outwards in either direction.

The underside of the bridge has been sanded to conform to the dome of the soundboard, initally using a domed platform to which I've stuck some 120-grit sandpaper, and then, by way of fine tuning, by taping some 240-grit sandpaper to the soundboard itself then moving the bridge to and fro across the sandpaper until the white pen marks I covered the bridge underside with have been removed.

I insert a clamp through the soundhole, positioning a piece of MDF that conforms to the bridge plate outline inside the body and over the bridge plate as I do so. With the bridge clamped lightly in place over the graph paper, I wriggle it into position, using my third mark to align the bridge's front edge at its mid-point, and the grid lines that run perpendicular to the soundboard centreline to align the bridge's front corners. The clamp is tightened, and I drill through the first and sixth bridge pin holes so that the bridge can be accurately pinned in position when the time comes to permanently attach it to the soundboard. The MDF inside the body prevents chipping when the point of the drill bit exits the bridge plate.

Removing the bridge, I replace the graph paper with a thin, low-tack adhesive film known as frisket film. I give the film a light scuff with fine sandpaper so it's easier to mark. I pin the bridge into position through the first and sixth bridge pin holes, and lightly mark the bridge outline onto the frisket. I remove the bridge and, using a craft knife, carefully cut through the frisket around 3/16" inboard of the pencil line, being careful not to cut into the top wood. I can then peel off the frisket that sits outside the scored line. I've found that by leaving a generous margin between the edge of the remaining film and the actual bridge outline, it's much easier to level-sand and buff the finish in the area of the bridge perimeter, bearing in mind that the frisket film is removed only when the finish has been buffed and I'm ready to remove the remainder of the finish within the bridge outline prior to permanently gluing the bridge.

In the interests of a neatness, I'll leave around 1/16" of finish inboard of the bridge outline, and rout a ledge fractionally over 1/16" wide around the underside of the bridge perimeter to a depth equivalent to the target finish thickness. To do so, I clamp my laminate trimmer to a MDF platform that's been domed to replicate the curvature of my soundboard. To prepare the MDF, I laminated two 3mm layers of MDF in my go-bar deck using a 25' radius dish as a base, then drilled a hole in the centre large enough to accept my chosen router bit. As previously described, the underside of the bridge has been sanded to conform to the dome of the soundboard before I rout the ledge.

As always, I'm open to suggestions and I welcome any comments.

Cheers
Pete