Archive for June, 2008

Binding and Purfling the Body

The binding is the outermost strip of wood around the edges and overlaps the joint between the top and sides; the purfling (if any) goes between the top or back and the binding. The binding is functional and serves to protect the relatively soft edges of the top from damage. The purfling is purely decorative and tends to be much shallower than the binding. I’m using koa for the binding and a very simple black/white/black laminate for the purfling. The first photo below shows the body ready to be bound.

I’ve found binding one of the hardest things to get right and potentially one of the most frustrating aspects of building. Like most builders I’ve found some ways to make it easier. The first difficulty is getting the ledge cut at the right angle. The ledge is cut perpendicular to a horizontal plane running through the body of the guitar, which is perpendicular to the sides. What this means is you can’t use a router resting on the top of the guitar since the top (and back) are both radiused. The purfling would then stick out from the sides since it would be square to the top, not the sides. There are several ways around this. I tried using a machine developed by Tom Ribbicke which worked very well in some areas but I found really hard to finesse around cutaways.

It took me a while but I was able to find a manufacturer that made an articulating arm that I could adapt for my needs. I’ve been very happy with the results. This arm gives me tremendous control over the tool which is the key for the kind of results I’m looking for.

ready for binding articulating arm bending the binding

Wood binding (and several types of purfling, like herringbone) have to be bent before they’re attached or they’ll break. I use the Fox bender for this and following the same procedure for bending as I did with the sides. After drying out for a few hours they’re ready to be applied.

I use tape for the majority of the clamping and bar clamps and rubber bands for some of the trouble spots. After drying I use a small block plane and scrapers to level the binding and purfling and finish with pneumatic sanders.

The last step before finishing is to fill the pores. Most hardwoods have tiny pores in them to conduct sap. Most of the time you can’t see these but they become very noticable once a finish is applied and need to be filled for the finish to be flush. On this guitar I used McFadden’s silica filler on the neck. The CA treatment I used on the body had ended up filling the vast majority of the pores so it didn’t need any further filling. After rounding over the edges of the purfling and finish sanding, it’s ready for the booth.

Neck

I build laminated necks which look very similar to the ones Jim Olson and several other luthiers make.  When I started building I found myself leaning towards laminated rather than solid necks.  There are several persuasive reasons for this:

  • Sustain can be improved by using denser, harder woods like maple and rosewood, but by using a proportion of mahogany the weight doesn’t climb to an objectionable level.
  • Laminated necks are more stable.  All woods have internal stresses.  We use processes (most noticably aging) to allow those stresses to lessen but they don’t go away.  Using several layers reduces the final input that any single piece of wood can have on the neck.  Additionally, the laminates can be flipped so the stresses of each type of wood in the neck oppose each other and cancel each other out.
  • Laminating necks allows smaller and thinner pieces of wood to be used which results in much less waste.  The woods used for making guitars are simply going away and using this process allows the builder more options without sacrificing quality or structural integrity.

I wasn’t sure just how I would laminate my necks until I saw Jim Olson’s which I thought were beautiful proportionally.  Thus the resemblance.  No point in change for change’s sake.  Or, if you’re going to steal, steal from the best.

preliminary thicknessing gluing heel stack glued and clamped all glued up preliminary shaping on bandsaw gluing on the “ears” routing the truss rod slot

Anyway, in the first photo I’m using a 13″ planer to do the preliminary thicknessing on the laminate pieces. Once they’re close I’ll use the drum sander to bring them to their exact size.

In the second photo I’m stacking the heel of the rosewood which will constitute the inner pair of laminates on this neck.  I use Titebond for this operation since I plan these joints to be permanent. (Titebond, a PVA or polyvinyl acetate glue, will come apart with heat but at a higher temp than plain aliphatic resin [white] or hide glues). The outer laminates are made from a solid piece of mahogany.

I use titebond and then glue it all together on the flattest surface I have in my shop, my table saw.  After sitting overnight the neck is ready to continue.  I first flatten the neck where the fingerboard will attach using the jointer.  This gives me an index surface for all the other operations.  Next I cut the heel using my chop saw with a 1 degree angle which reduces the amount of stock I then need to remove during the neck set.  Then it’s back to the jointer to flatten the headstock.  I use a bandsaw to cut away stock from the back and then glue on the ears. 

The last photo shows the truss rod slot being but on the router table. 

Next I cut the headstock to shape, glued on the headplate, bind and purfle the headstock then glue on the fingerboard. 

Fingerboard

This fingerboard is made of West African Ebony. West African is known for its consistent black color and is a little more brittle than Madagascar Ebony. My first step is to flatten one edge using the jointer and then reduce the thickness to 7/32″ on the drum sander. This goes pretty quickly.

The first photo is a simple indexing jig I made which I clamp to a sled atop my table saw. This can be done by hand but this is one of those situations where power tools simply do a far better job than hand tools. Of course, you need a good table saw and a sled to do this operation so nothing is for free, I guess.

indexing jig naugler-1447.jpg naugler-1451.jpg position markers fretting

I cut the fingerboard to size using a band saw to cut a wedge off of each size in preparation for smoothing on the shooting board (photo 2).  The ebony is brittle so I cut it on the band saw frets up (so chips come off the back which won’t be seen in most cases) and give it a little excess (maybe 1/16″) which them comes off quickly on the shooting board.

The next photo shows a little binding jig I devised using the same principle (and same clamps and wedges) as the system I use for joining tops and backs.  I routed shallow depressions in the jig which allow the binding to drop below the bottom of the fingerboard (maybe 1/32″) which I then plane flush with a sharp scraper.  This ensures a flush joint between the neck and the fingerboard.

This is one of the only tools I didn’t swipe from another luthier so I’m a little proud of it.  (Just a little since it’s less than a major milestone in luthiery development.)  So much of what we do is passed from one luthier to another.  Most of what differentiates one builder from another is the sum of the little decisions that are made during the building process.  To a non-player I would suspect many of the differences are not noticeable; to the player the differences are profound and are what give each guitar its character and feel.

Building tools and jigs is a lot of fun.  It’s a very creative process, one that I think most of us enjoy very much.  I think some of us actually enjoy the process of problem-solving and tool development as much or more than the actual instrument construction.  Jim Olson and Kevin Ryan both come to mind.  You should check out the workshop sections of their sites if you have some time.

The fourth photo shows the dot markers drying.  I’ve used a simple pattern on this guitar, using a forstner bit to drill shallow holes and inlaying paua abalone shell dot markers.  They’re then flooded with CA glue which is then sanded flush during the radiusing process which is what comes next.

 After radiusing the last step is to install the frets.  I use a fret press and install the frets before the fingerboard is attached to the neck.  While some purists may be groaning, this system allows for the most consistency.  It’s fast and does a beautiful job. 

Fur Peace Ranch

I recently had the opportunity to spend a couple of days at Fur Peace Ranch in Pomeroy, Ohio. FPR is a camp which was set up eleven years ago by Jorma Kaukonen and his wife, Vanessa. Jorma brings in 3 or 4 instructors during instruction weekends and class sizes range from 3 to 12 students per class. Students study with only one instructor for the weekend and the sessions are pretty concentrated. Jorma manages to get some really talented instructors, too, all of whom like to teach. I noticed that a guy named Steve Kaufman is on the schedule for next year. Never heard of him but he’s probably okay.  Jorma’s pretty picky.

I was fortunate enough to spend the weekend along with 12 other guys hanging with Tommy Emmanuel, certainly one of the finest acoustic guitarists that has ever lived. Tommy is a lot of fun to hang out with. He’s “one of the guys” and loves to tell lame jokes along with the rest of us. We really had a lot of fun. That first photo below is Tommy telling a joke to Steve James, a really superb blues guitarists who specializes in what he calls “blues roots.” Steve hails from Austin, Texas and is a very entertaining guy with more than a few opinions on this or that.

Bad pirate joke Student performances Tommy playing on the deck Tommy playing on the deck

The second photo is of the student performance. I think this is Jorma’s favorite part of the weekend. When he’s there he acts as both emcee and “roadie” for the students.

One of the joys of spending a weekend with TE is getting the chance to listen to him play and talk. Chet Atkins was his idol and he spent a lot of time with Chet in the years before he died and tells a lot of really cool stories of their time together. Tommy thinks with his hands and it’s just amazing to watch someone be able to express themselves so effortlessly with an instrument.   The last two photos are an impromptu session that Tommy had before class one day, after breakfast, when Tommy just felt like playing in the sun.  That 45 minutes was worth the price of admission alone.

Ray Bookbinder was there that weekend and did a short performance as did Steve James and Marjorie Thompson.  On Saturday night TE did a solo performance to a sell-out crowd at the Fur Peace Station, a small auditorium that is open to the public on concert nights.  FPR is located about 15 minutes south of Athens, Ohio, the home of Ohio University and Stewart-MacDonald luthery supplies.  You can check out some of the performances here. Tommy’s concert will air later this month. If you’ve never seen this guy perform, I recommend it highly. He has amazing stage presence.

The food’s just amazing, too. Virtually everyone who goes to FPR comes away with the same reaction: it was the best weekend of their life (not counting the 48 hour R & R in Thailand or whatnot). That was my third trip and certainly not my last.  Highly, highly recommended.




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