September 28, 2010
Spent some time squaring up the drum sander to ensure true surface sanding. Ran the back plates through several times and brought down to .110″. Used a shooting plane, then sanded to achieve perfect fit between plates (no sunlight shines through the joint). Used spanish joining jig, let dry for 2 hours then took a first pass at orbit sanding both sides of the joined plates.
September 21, 2010
The black epoxy used to glue in the headstock inlay dried overnight.
A wee bit of the shell can be seen peeking out from under the epoxy. After sanding on the belt sander, the inlay appears.
The center piece in the cheek moved a bit. I will pry it out, refinish the cavity and cut a new piece to fit. Also, I will score some of the border lines wider to further accent the demarcation between pieces, then flood more epoxy.
September 20, 2010
Now that the inlay for the headstock has been cut and mounted on card stock, it was centered and glued to the headstock. The perimeter of the inlay was used as a guide to score the ebony faceplate. A knife was used to pry off the glued inlay. Left behind is a nice scored outline of the inlay, and a dremel tool with an end mill is used to route out the cavity.
The inlay was dry mounted into the cavity to check for fit. After a few adjustments, the inlay rests nicely in the cavity.
Black epoxy is mixed up and the cavity is flooded, the inlay squooshed in and then more black epoxy is glooped on to the surface. Parchment paper is laid on the surface, with a wood scrap on top weighed down to press epoxy into any gaps. This will be left to dry for 24 hours before sanding to reveal what I hope is a very nice design.
September 19, 2010
The raven design size will by 80% of the original to fit nicely on the Gibson-like headstock shape. Using reproductions glued to MOP and paua, the shell is cut out in sections.
The majority of the design will be in MOP with accents and teeth using paua. This photo shows the first sections ready for cutout on the shell sawing jig.
Once the MOP is all cut out, the paua accents are cut.
After cutting the final pieces, they are glued to card stock.
After the glue dries, the card stock will be trimmed flush with the shell, then any rough or misaligned edges will be filed smooth. This assembly will then be glued to the headstock and a cut line will be scored all around the inlay. The glued inlay will be removed from the card stock and the headstock and the cavity will be routed out using a dremel.
The individual pieces will be placed in the cavity to determine final shaping of each piece before gluing in with black epoxy.
September 8, 2010
Headstock design has been finalized.
September 8, 2008
Rosette construction for the Koa Dreadnought begins with locating the center of the soundhole, drilling a 3/16″ hole then mounting on a center pin on a workboard on the workbench. This pin matches a dremel circle cutting jig. A downcut end mill is used in the dremel to cut channels for the rosette purfling.
First and second pass is for the inside and outside rings with a 3/32″ end mill.
After the channels are routed, the purfling is installed with white glue. Each purf strip is pressed in and the glue squeeze out is cleaned up.
Before routing the center channel, the installed purf is allowed to dry and then scraped down to plate surface level.
The center channel width is 2 purfs plus a .063″ center teflon strip. The teflon strip is the same width as the Abalam shell which will go between the inside and outside purf in the center channel. The channel is prepped with white glue and the purf/teflon/purf sandwich is pressed into the center channel.
After drying, the teflon strip is pulled out, the cavity is cleaned up to remove any dried glue clumps, then curved Abalam strips are pressed into the cavity. CA glue is flooded onto the Abalam. Several applications of CA are needed to fill the channel before the rosette rings are ready to be scraped flush and sanded. Only after the rings are flush will the soundhole be cut out.
September 6, 2010
The top has been planed down to .105″ in preparation for joining.
Using a shooting board and plane, the edge is jointed, then glued and secured in the joining jig.
After an hour in the jig, the plate is removed and the glue squeeze out is removed with a cabinet scraper. The top is then fine sanded. The joint has been notched at both ends to positively locate the center line. The dreadnought top template is used to trace the top shape to the outside and locate the center point of the sound hole.
This is really a very nice piece of Sitka Spruce. It has lots of waterfall curl which is very subtle yet pleasing. The center of the soundhole is drilled with a 3/16″ bit and the plate is mounted on a workboard with a 3/16″ pin in preparation for routing the purfling channels.
The back plates started at .170″ and need to be thickness sanded down to .090″. My drum sander has a few issues which need resolution. First issue is the drive belt drifts off center and needs calibration. Second issue is that the drum is not within tolerance of being parallel (drum to drive belt). Additionally, koa tends to burn slightly in the drum sander.
Once these adjustments are made, and the sanding drum has been cleaned up to remove previously deposited burn streaks I will be able to sand down the back plates to approximately .100″ in preparation for joining.
September 1, 2010
I sent 3 options for the headstock to Steve for his approval. Using his raven inlay design, the first option was to position the raven aligned to the top of the headstock.
The next two are variations of the same alignment, with the raven down between the tuners.
June 10, 2010
After the neck block extension came out of the clamps, I was able to trim it down and flush it up with the original block.
It is now a wee bit oversized, but I’ll trim down the height just before gluing it to the sides.
I trimmed up the ebony headstock veneer after it too came out of the clamps. I level sanded the neck where it glues to the fretboard, remeasured where the 14th fret should land and traced out the heel curve, then sanded it out with the spindle sander.
I also sketched in the eventual thickness of the headstock and the taper for the back of the neck from the headstock to the heel. After installing a new blade in the bandsaw, I’ll cut to the sketch lines in preparation for initial neck shaping. I won’t shape the neck until I receive the headstock inlay, as routing out the inlay channel will be easier to do with a squared headstock secured in the vise.
June 9, 2010
I augmented an OM neck block to accomodate the larger size needed for a dreadnought.
The added piece is oriented with the same grain direction. It will be trimmed to match the dimensions of the existing neck block.
Spent considerable time flattening the top of the neck and the headstock. Installed the ebony headplate and will trim down flush with the mahogany once glue sets.
I’m waiting for a designed/constructed headplate inlay. I’ll determine the headstock shape based on the inlay design.
