Monday, February 28, 2011

More work on the body...

With the sides bent to shape and the neck and tail block cut and shaped, I got a chance to do more work on the sides/rim structure.   I started by fitting the loose sides back into the mold.  Then marking the head and tail block areas and trimming the sides to their final length. 















Next, I glue in the blocks.
 Once they dry,  it all goes back in the form and its time to sand the top and back edges flush to the blocks. Then the kerfed lining gets added around the top and back edges.   Here, I'm dry-fitting the kerfing around the top edge before glueing.  It will be glued in just proud of the sides so it can be re-sanded flush before the top (or back) is glued on.


Wednesday, February 16, 2011

Bending Sides



I started by sanding the side wood down to just above 2mm...or approx. .080.     Then, traced the side profile template onto the wood adding about 1/4 in. in all directions (even more at the neck and tail block locations).

I mark the waist area or tightest portion of the curve so I can index this in the side bending machine.







 
The Fox side bender is just a primitive clamping device designed by a luthier named Charles Fox that lets you bend sides around a form and clamp them until the curve sets... It consist or a center clamp, a sandwich of metal slats, side wood, and another metal slat,  a form in the shape of the guitar you're building and a way to heat everything up to bending temperature.  In the past I've used 3 - 100 watt light bulbs built into the base of the bender,  but on this one,  I have access to a silicone heating blanket with a temp setting and timer.

After the sides are the correct thickness,  I start by prebending the waist area on a hot pipe to help that area get a head start with bending in the bending machine.   Next, I'll use a spray bottle to wet the side wood with water and wrap the side in a piece of paper.  The paper helps hold the water in and keeps the wood from getting stained or scorched. 

Once the metal slats are added on either side of the wood, the heating blancket gets added under the whole sandwich and all of this is slid into the bender and the center/waist block is snugged down.   The blanket gets turned on for about 5 minutes on the timer.  It heats up quickly and within a minute or so,  the center clamp can be tightened a little more.  At this time, both ends of the sides can start to be bent around.

When the water in the wood starts to steam,  the ends of the side can be pulled down and the front and back clamp can be added and tightened.  

Finally, the center clamp can be tighetened down and seated, and the entire side cooks for about another 10 minutes then gets left to cool for several hours.

Monday, February 14, 2011

Mahogany Back and Sides

This weekend I got a chance to start back on the braces for the second top.  I added the main X braces and the maple bridge plate.









The Mahogany pieces arrived for the back and sides....and they look great.  I'll have to thin them down before I can bend the sides.

Tuesday, February 8, 2011

Body Form


At this point I have the Mahogany back and side sets on their way so I decided to build a body form for assembling the body.

Building the form was pretty straight forward. I used 1/2" MDF and 3/4" dowels. I started by tracing my half pattern of the guitars shape onto a piece of MDF and used that as the master. For each additional piece, I traced the master and drilled the corresponding holes for the dowels. Next, I cut the tracing close to the drawn line and attached this new piece to the master and used a pattern tracing bit in a router to clean up each new piece so that it matched the master each time. Once I had the 6 matching pieces, I stacked 3 on each side using scrap 3/4 plywood pieces as spacers and inserted the dowels with glue.

I've joined the two halves by glueing in a couple of 3/4" plywood blocks. Some builders prefer to keep the form in two pieces that can be split but I'm building this one as a one-piece form. The guitars body can be removed easily without having a form that hinges open and the one-piece will be stronger and more rigid.

Why the red MDF? Just happened that the scrap MDF I had around was painted red in a former life...

Building the tops


The first thing I did after joining and sanding the tops was to insert the soundhole rosette. I chose to use a combination of two pieces of ivoriod binding sandwiched around a piece of thin black fiberboard.



Next, I joined the tops and sanded them close to final thickness using a drum sander and cabinet scrapers.


Both tops have grain patterns varying from fairly tight grain to wide grain. I chose to join one of the tops with the tighter grain bookmatched toward the center seem and the other top with the wide grain near the center.


I ripped the bracing stock and thicknessed it according to the plans. Then I sanded the radius of the top curvature into each brace using a radiused sanding form and glued each of the braces to the top using hot hide glue.


Above, you can see that I'm using a go-bar deck to clamp the braces until the glue dries then the braces are carved down to their final size and shape.






Getting Started


The first thing I did after deciding what I wanted to build, was to find a suitable set of plans/blueprints. There are several available on the interenet; some offer free downloads and some for a fee.


I selected one that I liked and downloaded it and printed it out full
scale to make a working copy.

The next step is to decide what you want to build with. I chose Adirondac Spruce and Mahogany. I ordered two tops from Old Standard Wood. I specified that I preferred wide grained tops with as little color in the center portion as possible since I'd be sunbursting the top. Color stripes near the outside edges will likely be covered by the sunburst.

They sent me two really nice, wide grained tops and more than enough wood for bracing the top and back.