Archive for the 'Kamp Guitar' Category

Finished Guitar

I realized recently that I had never bothered to publish photos of the finished guitar.  I apologize for that and will have them up soon.

Seth

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.

Top Bracing/Joining the Top, Back & Sides

 I’ve gotten a lot done in the past week and am a bit behind in the blog.  The fingerboard is almost done and the neck has been made and needs shaping and purfling.  It’s coming together quickly.  It goes in the spray booth next week.

The first photo below is the obligatory “luthier carving braces” photo. I’ve shaped the back braces using a couple of those little planes I have and a sharp chisel and am cutting the ends of the braces down to 3/32 to get slotted into the kerfing.  All the trim that runs vertically needs to be installed before I rout the binding ledges.  This includes the end graft (below) plus the trim around the point of the cutaway and the joint next to where the heel of the neck meets the body.  I’ve opted for very minimal decoration on the guitar and will be using koa binding which will look really neat against the rosewood.

 The next photo shows the side braces being installed.  The sides of the guitar are very thin and are prone to cracking, usually when you’re resting the guitar on your leg and something hard (like your keys or change) press against the sides.  These help minimize this.  After that I routed the slots for the braces and glued on the back.

Finishing the back End Graft Side Braces 

While the back is setting up I’m back to the top.  I cut the rosette using a Dremel tool and a really neat little router base that Stew-Mac sells.  The router rests on a pin stocking out of a piece of plywood (first photo).  The router then just pivots about this point and cuts the channel.  The trick here is to go slowly and using climb cuts most of the time.  I’ve chosen a narrow band of paua abalone shell (abalam, actually) edged with fine black and white purfling.

After that dries I plane the purfling down and then level the rosette using the drum sander.  Now it’s ready for the braces.  I transfer the pattern from a plan to the backside, then use the jig to cut out the soundhole the rest of the way.  Braces are shaped in the radius dish just like the back (30 feet this time, though) and glued to the top using the go bar deck.  After final shaping and sanding I glue on the saddle plate and the fretboard extension support block at the top of the last photo on the right.  This helps transfer the tremendous forces laterally to the big transverse brace right below it.

Rosette Jig Routing the rosette Rosette Transfer the pattern Gluing on the braces Top, signed and ready to go

Back in the Go-Bar deck.  A few hours later the guitar can be removed from the mould.  I use a flush trim bit in a router the trim the top and back.  Now it’s ready to be bound.

Gluing the top in the Go-Bar deck Body, ready for binding

I’ve skipped a lot of the small steps and sometimes the order of things is slightly different.  I usually have several things going on at once and am moving back and forth.  I’m also building three guitars at the same time so it gets confusing.  If you have any questions about what I’ve done feel free to email me if you don’t wish to post them publicly and I’ll be happy to get back to you.

Back Prep

The first photo below shows the attachment of the back strip. The back strip is a very thin piece of wood (maybe 1/16″) and maybe 5/8″ wide with the grain running laterally (rather than longitudinally which would be much easier to rip) which is used to reinforce the glue joint on the back, historically one of the weakest joints on the guitar. The second photo below shows my logo branded into the back strip. I use a brand I bought from Rockler which is low-tech by today’s standards (I can’t justify a laser, at least not yet) but works really well. It makes me nervous every time I do it, however, like bending sides.

gluing on the back strip branding

The first photo below shows your’s truly cutting out braces from rough stock.  I use either Sitka spruce or mahogany for the back braces and usually use Sitka for dreadnoughts to keep with tradition.  I use 1/4″ bracing exclusively now rather than a more common (at least among factories) 3/8″ wide.  Martin has taken to offering 1/4″ bracing on some of their guitars, I think several of their “vintage” models.  1/4″ is a little harder to work with but it’s used for a good reason.  By narrowing the brace 33% and increasing its height  by a few percent, as any engineer can tell you one ends up with the same rigidity with significantly less mass.  Mass is the enemy of sound (on the soundboard and back, that is, not necessarily elsewhere–sustain is often improved by mass in other areas).

cutting back braces shaping for the back radius Go-Bar Deck

The second photo above is me shaping the backs of the braces to the back’s 12 foot radius.  I use a template to trace the radius on the brace then use the belt sander to remove the stock to the line with a final sanding on the sanding dish.  This gives the back tremendous strength for its weight.

I use a razor and a chisel to cut slots in the back strip to accomodate the braces.  I just think it’s easier than cutting relief into the brace itself and, as any of you following this blog so far might have sensed I try to take the easy way out whenever I can.  I’ve used the bandsaw to pre-cut the “ramps” on the braces but will use a chisel to do their final shaping.  I try to use power tools to remove as much stock as possible during production.  While purists will scoff at this I do it for several reasons:

  • It reduces tedium.  I have a short attention span and removing stock is boring.
  • It improves quality.  If I’m bored I’m more likely to make a mistake.
  • It improves consistency.  Using machines and jigs makes following specifications much easier.
  • It improves safety.  Boredom equals complacency which increases the likelihood of me doing something stupid and getting injured.
  • It improves health.  Much of stock removal, especially when shaping necks, can be physically hard on the builder.  Carpal tunnel syndrome and repetitive stress injuries are greatly reduced by the judicious use of power tools. 

Years ago as a carpenter I developed the philosophy of using the right tool for the right job and I try to do the same in my shop. 

I want to make the point here that I don’t believe that my approach to building is the only one or even the best, while I think it is the best for me.  We are in what many have called the “Golden Era of Lutherie” and there are many builders out there building guitars with different approaches and different philosophies of building and each has validity.  While the dimensions and basic design of a guitar are pretty similar from one builder to the next, the final products are amazingly different in their smell, sound, playability and overall feel.  So much of the personality of the builder insinuates itself into the product.  There’s more than one way to skin a cat.

 I use a Go-Bar deck to glue the braces on. The Go-Bar deck is a really handy tool for the small shop.  It’s fast, easy to set up and allows for the distribution of pressure over a wide area. 

All that’s left for the back now is to shape the braces using a tiny block plane, finish the scallops with a really sharp chisel and sand.

Kerfing

The sides are now ready to have the kerfing glued on in prep for receiving the back and top.  You can see in the first photo that the inside of the sides is a little darker than the outside; that’s the result of the treatment with CA.
Sides Ryan A4 Kerfing 3D

The second photo shows Kevin Ryan’s A4 kerfing.  Kevin uses a laser cutting machine to make very thin-kerfed cuts of the wood but cuts both sides which allows the kerfing to move in three dimensions like one of those old watch bands from the 60s and 70s from Speidel.  Very, very clever.  It solves a lot of problems.  You no longer have to break the kerfing in several places to allow it to curve along the radius of the back, a problem especially noticeable around the cutaway.  The installation is faster, too, and ends up with very little or no squeeze out (fourth photo.)

easy clean up Chalking

After both the top and back are applied I whip out my daughter’s chalk again and mark up the edges, then sand the kerfing flush with the rest of the sides using the radius sanding dishes again. This step takes only a couple of minutes.

Next steps: putting the neck together and inlaying the rosette in the top.

Filling Bug Holes

Like much old Brazilian this set has some flaws.  It has some small cracks on the backs near the bottom, a couple of weak spots on the sides and half-a-dozen worm holes on each side, two of which are fairly large.  The cracks on the back I’ll probably fix after the backs have been attached to the sides.
holes in sides
I’m not going to go out of my way to hide the holes, just fix them. I read somewhere recently that the existence of wormholes is a sign that the wood is genuine Brazilian; it also fits in with my philosophy that the flaws give the wood character and add to the overall beauty.

I’ve used a scraper to collect a little bit of sawdust from the sides (that’s what’s in the little plastic cup). You don’t need much. I’ve also cleaned some of the stains near the bug holes with naptha. Naptha is pretty effective at removing mineral deposits from rosewood as well (that’s the white stuff that won’t sand off, often found in trees that were grown for shade in plantations–not sure why).

back up the hole with tape Fill with sawdust glue

First I use a tiny piece of tape to back up the hole on the inside, opposite the side I’ll repair.  This keeps glue from running all over the place.  I drop a little mound of sawdust on top of the hole and then rub the sawdust back and forth pushing it into the hole, then put a tiny drop of super glue (cyanoacrylate or CA is the glue of choice here, thin viscosity). After it dries I add another drop of glue, sometimes using medium viscosity for this. I don’t use accelerator for this operation since the reaction can trap gas bubbles which turn white. Then, using a tiny sanding block (I use a tiny piece of pine or mahogany with a piece of 150 or 220 grade paper glued to it), sand flush. On the inside, I peel off the tape and then use a scraper to make the repair flush.

For the two larger holes I’ve taken a piece of scrap from the end cuts and cut tiny plugs.  The principle is the same:  push the plug in following the grain orientation, tape the back, fill hole with CA, dry, fill again, dry, sand flush.  If you see the guitar in Maryville you’ll be able to see these holes as I’ve made little effort to really “hide” them, just fix them.  But they look “right” if you will.

The last step today is probably going to seem a bit unorthodox.  I got the idea from C F Martin & Co.  I read somewhere that they, like everyone else, can always use more Brazilian and will, depending on the grade, immerse the wood in a bath of cyanoacrylate before they use it.  (That’s super glue.)  Using CA as a way to fill and harden the fibers of wood is an old repair guy’s trick and works extremely well.  I didn’t take any photos but the process is simple.  Using a respirator and working in my spray booth, I use a disposable brush to apply glue on the wood.  After drying I use a scraper and sandpaper to remove any excess.  During the process you can see that some areas absorb more glue than others: these are the weak spots.  Besides improving the strength of the wood it will also improve the tone, making the wood more rigid.  It also darkens the wood considerably.  If you plan on using an absorptive stain you should apply it before you begin this process since the CA effectively seals the wood.

 Next:  Kerfing, with Kevin Ryan’s really cool new material.

Radiusing the Sides

I’m currently using an old-fashioned, hands-on technique to dimension the sides. The sides (or rim) need to be tapered since the tail of the guitar is deeper than the heel. In addtion they need to be radiused since both the top and back are domed rather than flat. Some makers don’t radius their tops and have had a lot of success using that approach (Kevin Ryan and Jim Olson) but I’m not there yet. I still feel more comfortable with the added strength the domed shape gives.

Sanding dish planes and chisels

I use a block plane to remove stock, taking it pretty liberally from the heel block and a lot more conservatively from the tail.  I own a slew of planes, some of which I acquired years ago when I was a carpenter but most of the ones I use now I’ve acquired over the last few years.  I’m particularly fond of Lie-Nielsen planes.  They’re heavy and really precisely machined.  They’re worth the cost.  Some things you can go cheap on but planes usually aren’t one of them.  A good plane is a joy to use and a bad one is a pain in the butt.  I bought an inexpensive jack plane a few years back and ended up throwing it away.  The mouth was machined a degree or more off square which made the thing useless.  Planes need to be sharp, too.

Anyway, I repeatedly lay the guitar in the radius dish and look for light.  Wherever it’s touching I remove stock.  When it gets close I mark the exposed wood with a big piece of chalk I swiped from my daughter and begin to sand.  When the the chalk is gone you’re there.

I make index marks on the inside of the two blocks on both sides when I start on the back.  The back takes four times as long to do since there is so much stock to remove.  The principle is the same but you have to be careful.  I use a 30 foot radius dish for the top and a 12 foot for the back on all of my guitars so the back ends up being much more radiused or “curvy”.  Some folks will say this radiates sound toward the soundhole which may be true but I just think radiused backs are cool.  They fit in the lap better and just look and feel nice.  Because of the radius, however, you’ll end up taking more stock off the bouts than the waist.  I try not to hurry, using the same technique as the top, putting the sides in the radius dish and using a backlight to check for gaps often.  Also, as I remove stock I periodically check with a ruler to see if I’m taking off stock symetrically.  When I’m close I chalk up the edge and sand away.

Using a backlight to check for gaps Ready for hole filling

This process takes at least a couple of hours, often more.  I’m constantly looking for ways to reduce the time it takes to make guitars and improve the quality.  This is one of those things that can be sped up and I’m working on a jig to do just that.  Anytime you find yourself spending hours removing stock you can probably assume that this might be a good area to innovate (or steal as the case may be).  I was out in Kevin Ryan’s shop last week and Kevin uses a really neat jig to radius the backs of his guitars.  I plan on using his jig as a model to do the same.  Kevin’s shop is really wonderful.  I think he enjoys making tools and jigs more than he likes building guitars. 

Kevin had just finished a “Ghost” guitar which has a redwood top that had been submerged for quite some time giving it unusual tonal qualities.  I got a chance to play it for a while and it was wonderful.  He builds great guitars.  Heck of a nice guy, too.

This guitar uses some old Brazilian Rosewood and, like a lot of the stuff available today, needs some work.  There are a dozen small wormholes and two larger ones that need to be filled.  That’s next. 

(The guitar is further along than the blog so I hope to make several posts in the next week.  Thanks for checking in.)




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