MARK'S GUITAR, PART 1

     In 2003 I hooked up with Mark Chanlynn, an old college friend I hadn't heard from since about 1969.  We roomed together as gunsmith students at Trinidad State Jr. College in Colorado.  He went on to be a gunsmith just as he planned, while I went on to, oh, let's just say other things. Mark was the first person I met who actually played guitar (as opposed to just owning a guitar).  He turned me on to a ton of music I'd never heard before and probably ( in retrospect) inspired me to pursue music in general and instrument making in particular.  Just as I came back to shooting after a 20+ year lay-off, so Mark came back to guitar playing.  So we decided to swap crafts.  He built me a fancy varmint rifle, and I built him a fancy guitar.  I thought it would be fun to do a step-by-step pictorial of the growth of Mark's guitar.  One note though---I wanted to build a prototype to test the mold and sidebending jigs before I committed Mark's Brazilian rosewood and Engelmann spruce, so I also made a similar guitar out of canary wood and Western red cedar.  Both guitars turned out to be gorgeous musical tools.  The finished canary wood guitar can be seen on my recent work page(And by the way, Mark's rifle is an astonishing piece of work, too).

      The book-matched top and back sets are run over a jointer before glue-up, but the joint is never good enough right off the machine.  The joint is perfected on a shooting board using 80-grit sandpaper glued to a carpenter's level.  This trick can be hard to learn, but once you've got it down a perfect edge can be achieved in a minute or two (above).  Once joined, the profile can be drawn on the plates and cut out on a bandsaw.

Here Mark's 3-piece Braz back sits on top of the 2-piece canary back.  The abalone back strips have already been inlaid in the rosewood.

The rosette is made up of commercial purfling strips and lengths of abalone .047" wide.

Simple tools are used to build the rosette, after which it is flooded with super glue and then sanded flush with the wood.  The abalone pieces are carefully broken as they are put in to make the curves.

The abalone rosette sits upon the all-purfling rosette of the canary guitar.

The abalone in the rosewood back was installed in the same manner.  The white centerline is still in place here.  It's only pencil and will be sanded off.

This is a top flex jig.  The top is suspended over the table and pinned in place.  The dial indicator is brought down to just touch the wood and that figure is recorded.  The white box is mounted on a dowel that is lowered through the beam until it presses on the top.  Another reading is taken, and the difference is the top flex.

Here's another view.  The skinny piece of walnut across the soundhole just holds the top flat on the suspension pins.

If the top is too stiff it is run under the thickness sander and another reading is taken.  A few thousandths can make a big difference in the reading.

The readings are recorded on the top.  At first reading the top was .132" thick and the deflection reading was .142".  The next pass nailed it at .120" thick and the desired deflection of .178"

The left over brace stock isn't worth H&D's attention, but all of it is kept.  Here's some of the scraps.

But with a little work it can be turned into a nice little stack of quartered stock.  I'm told Martin has an upcharge of $400 for red spruce braces, making this little pile of lumber worth about $1200.  Silly, huh?

Before braces can be glued to the plates the grafts have to be put on the back seams.  The grafts are made of top material (cut cross-grained) and only serve to reinforce the glue joints in the back.  Here the first one is being glued.  A plexiglass guide is also clamped in place.

Both back grafts have been glued on.  The back has been taped off while a small plane is used to round over the rectangular stock, after which curved sanding blocks will clean up the grafts.

OK, here's a quick sequence on making braces one at a time after they're sawn out of the billet.

The bottom of each brace is sanded to match the radius of the top or back.  This is the H&D Beast, a motor-driven sander.	The brace bottoms are evened out by hand on another radiused form.	The ramps are traced off a brace pattern or another brace.
The ramps are cleaned up and sanded to .090" thick on the spindle sander.	Each brace is hand-shaped on the belt sander.	Here's a close-up.  The braces are then sanded to 220 grit, at which point they are done.

Braces are glued to the plates on dedicated jigs.  The deck of each jig is a radiused form matching the arch of the braces, a 15' for backs and a 25' radius for tops. 

First the brace pattern is marked on the back seam grafts.  The grafts are segmented with razor saw and chisels to make  channels for the braces to nest in.	The back braces are being glued in place

The top braces are glued in a similar jig	Here the X brace and the cross-graft have been glued.

Mark's top is completely braced.  The X brace is done, but the rest of the lower bout braces will be scalloped individually later.	Mark's back is ready to go.

We haven't seen much of the canary wood prototype lately.  Below are the top and back ready to go.

    Here's a little story about braces.  C. F. Martin invented the X brace before the American Civil War.  The pattern was pretty much set by 1857.  It was for gut strings and not wire.  But by 1900 many players were putting wire strings on their guitars for more volume and a different tone, and by 1917 this action was so prevalent that Martin beefed up their bracing to meet the stresses of steel strings.  The bridge plate was also enlarged.  However, metallurgy and string design have come a long way since 1917. When Huss & Dalton decided to make a OO size guitar a 1901 Martin was copied, not to the Nth degree but the size of the X brace and tone bars was carefully maintained.  It was felt that light gauge strings would do well when combined with the old gut string bracing and the results have been incredible.  These little guitars put out a volume and tone all out of proportion to their size.  I lengthened these same braces and put them on the Ferrari OM and the results were stunning.  I've made other such OMs with equal success.  Mark's guitar is braced the same way, as is the canary wood guitar.  Look at it this way---almost all guitars are made to withstand the tension of the heaviest strings on the market, plus a safety factor since a long run of guitars coming back for warranty work could kill a company.  No wonder medium gauge strings always sound better than lights.  But light gauge strings can sound just as good if the guitar is designed for them, and the guitar will be easier to play.  The lure of medium strings must be ignored, however, as such strings could hurt a lightly brace guitar.

    When a new model guitar is created (or even a significant variation) its necessary to make some new fixtures to assist in the building process.  Huss & Dalton's OM mold is one of the most accurate in the shop, so rather than make a new mold for Mark's guitar I decided to adapt the old mold for a cutaway.  A new pair of side benders also had to be made up to bend the cutaway side.

Above left is the altered mold.  At right the new addition has been separated for a better look  The mold has a series of add-ons that we'll see later after the sides are bent.

The cutaway side will be bent in two stages.  Above is the first-stage form sitting in front of the form for the non-cutaway side.  The camera has skewed them to look more alike than they really are.	Here the form is mounted in the Fox bender.  This is the original H&D bender that has bent hundreds of side sets and has been much altered along the way.  A second bender sits behind it.  Note that the new bending form is sitting on a height extension unit.  Without it the Fox bender would get in the way of the bending process.

Most of the time new jigs and fixtures have very humble beginnings.  This 6" stack of plywood is the beginning of the 2nd-stage cutaway bender.

OK, here we go with Mark's guitar

Paper side patterns were pulled from the canary wood guitar and placed on the Brazilian rosewood sides, to which measurements they were trimmed.	The wet sides are placed in a bending sandwich of blued spring steel, aluminum foil, and an electric blanket.  The sandwich is merely pinched in the bender until the heat comes up to 275 degrees.
	A side loaded in the Fox bender.  Thank you, Charles Fox, for one of the luthiers' best friends.

The bent sides before the cutaway horn is added.  The canary wood was hard and stiff, much more so than mahogany, but Brazilian rosewood is pretty much in a class by itself.  Only Honduras rosewood, African blackwood, and the ebonies will match or surpass it for difficulty in working.  Braz might be nasty to work with but it's still the wood against which all other guitar woods are measured.	Second stage bender for the cutaway horn.
	Second stage bender loaded.  The horn is locked in place, then the middle clamp is swept to the left to bend the cutaway until the spring clamps can grasp the side.  Good view of the heat blanket.  The white spot in the background is a contact thermometer.  I think the wooden shoe needs to be modified to take into account the thickness of the side sandwich.
Finally, the sides have been loaded in the mold and the end blocks glued and clamped in place.  The steel clamps helping the ribs conform to the mold were invented by Mark Dalton, and I have always called them Dalton clamps.  With wood that is feisty and hard to work with they are an enormous help.  A sheet of Forimca has been placed behind the mold to eliminate background clutter.

	OK, this is how the guitar is going to live for the next several operations.  The sides have been ground on the Beast machine to correct the depth and fit them to the contours of the radiused plates.  The spider system of clamps helps the ribs conform to the mold, and also supports the sides during grinding and the glue-up of the plates.
All the edges of the rims are covered on the inside by lining (also called kerfing).  The lining is glued on proud of the rims, and after the kerfing is sanded to 220 grit the edges will be ground to match the contours of the rims.  The lining supports the delicate edges of the rims, stiffens the whole unit, and provides additional glue surface when the plates are joined to the ribs.
The ribs always look so clean after grinding.	A micro saw mounted in an X-acto handle is used to mark the brace positions on the ribs.

A dental pick is used to mark the braces on the outside of the ribs.	The braces are trimmed .110" inside the pick marks
The braces are trimmed with a razor saw and chisel.	A mini router is used to cut pockets in the lining for the brace ends.

Braces are put on the top oversized, then chiseled into scalloped ramps to remove excess wood that might impede the best tone.. . . .	. . . .like this.
	The inside of the top is marked for future reference.
The guitar (still in the mold) is placed in the body press where it nestles between forms that are built with the same radii as the top and the back (25' radius for the top and 15' radius for the back).  This big clamp is tons faster than using a plethora of little clamps.

	The body usually looks pretty raggedy and dirty when it comes out of the mold.  There's still much to do, but it's all mostly cosmetic.  But it's the cosmetic touches that give a guitar its character and much of its value.
	Everybody likes to peek inside, even though it doesn't tell you much about how the guitar is going to sound.
It still doesn't look like much, but the hardest part of body building is done and only the fun stuff remains.

Many thanks to Jeff Huss and Mark Dalton for the use of the company shop after hours!

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