Friday, February 24, 2012

Under the Bench Lamp - Norman B20 (continued)

I'm back after a few days of non-blogging.

Since I last blogged about the Norman, I have put a spruce patch on the soundboard under the tongue to replace some chewed-up (but unexposed) top, placed a rosewood shim under the tongue to eliminate its unacceptable drop-off,  and re-installed the neck.  Some highlights are pictured below:
Here is a shot of the cleaned-up under-tongue portion of the soundboard ready for a spruce patch.

The patch is properly thicknessed and dry-fit.  It will be completely covered by the rosewood fingerboard tongue.

The patch is glued and clamped.  That bag sitting on the soundboard of the lower bout is a sack of lead shot.  It is great for stabilizing a guitar that is being repaired.  You can see I used titebond and wax paper with clamping cauls inside and out.  The patch is dead flush with the top.


Pictured below, laying next to the fingerboard, is the shim I made out of rosewood.  I started with the band saw and ended with the belt sander.   Though you can't see it in the pic, it's about .040 inches at the thick end and tapers down to as thin as I could get it.....maybe about .004 inches....paper thin.



My trusty caul with a 14" radius.  Perfect for this fingerboard.

I glued the shim on first.....let it sit overnight and then installed the neck.  Here it is all glued and clamped.

The shim is in and the neck is on....and, after some very careful hand work with chisels, files and sand paper, I am pleased.....the shim is doing its job and almost invisible.
After taking the clamps off,  I was super eager to check the fret board flatness and neck set.  Much to my delight, the fingerboard is flat....no more nasty drop-off.....and the neck is very, very slightly over-set......which is more than okay.  After I take the leveling bar to the fingerboard and string it up to full tension the neck set should be perfect.  More pics on that later.

Next week I will perform a complete re-fret and deluxe set-up on this Norman......stay tuned (no pun intended).


Friday, February 17, 2012

Under the Bench Lamp (B20 Norman Continued)

To refresh your memory, I am faced with two options in repairing the B20 Norman. Have a nice straight neck and a slightly visible shim under the tongue or no shim but a pretty dramatic tongue fall-off.  I chose to put a shim under the tounge.  IMHO, this is the right call.  Playability trumps minor cosmetic issues on non-vintage guitars.

So, this morning I removed the neck.  But first, I removed the frets over the tongue.  These frets act like little wedges that stiffen the fret board.  Taking them out will make separating the tongue from the sound board and removing the neck a little easier.

I use a soldering gun to heat the fret so it will "let go" with minimal chip-out.  Notice that I am using a guard to protect the fret board.  I don't plan on slipping with the soldering iron but better safe than sorry.  BTW, if this guitar had pick-ups, I would be using a soldering pencil, not a gun...guns create a magnetic field that can damage pick-ups

After heating them up, I gently pry them out.....letting the pinching action of the jaws do the work.  I am in no hurry here.  Slow and safe is best.

All done. And little to no chip-out.   I will save these frets for later.  They are not worn and can be put back for dressing.
 Now it's time to separate the tongue from the sound board.
Not a good pic.  I am using a hot plate to heat am aluminum block to about 350 degrees.  Once it gets to temperature, I will place it on the tongue for several minutes.  The heat will penetrate the rosewood and soften the glue that attaches it to the soundboard.

With the glue under the tongue heated and softened, I will use these tools to separate the tongue from the sound board.

 I am starting to separate the two glued surface.  I will be working fast while the glue is still soft and warm so no more photos until I'm done.

All done.  Now that the neck is off, I will clean up the bottom of the tongue and start to fabricate the wedge.  You can clearly see the adjustable truss rod and some markings made at the factory.
Well, it's the weekend and I probably will not work on the shim until Monday.  I have another guitar in the shop that I need to evaluate today.  If it is interesting, I blog about it later.

Have a great weekend.

Wednesday, February 15, 2012

Under the Bench Light - The Norman B20 (Continued)

Okay, I lost sleep thinking about those covered neck bolts and the fact that I should have checked their tightness before I pronounced that this guitar needs a neck reset.  So, first thing this morning I headed to my shop to check it out.

I loosened the strings and used an razor knife (and my fingers) to remove the label covering the neck bolts.
Look at the round inspection mirror....you can see the two uncovered neck bolts


I masked off the sound hole (I am all about not scratching, denting or dining  guitars) then used a socket wrench  to tighten up those neck bolts.
Well, was I surprised.  Those bolts we finger tight....at best.  So, after a few cranks on each one with an 11 mm socket I put the guitar back on the neck jig and tuned it up to pitch.
My favorite tuning fork
In the jig and on the playing position, I put my 24 inch straightedge on it.  Much to my surprise, the neck set was right on.....the straightedge just skims the top of the bridge, which exactly what you want.  Tightening those neck bolts pulled the neck back into the proper position.

Only one problem.  If you remember yesterday's post (before tightening the neck bolts), I talked about being able to adjust the truss rod so the playing surface was nearly perfectly flat all the way to the last fret.....but doing so resulted in an under set neck.  Well, tightening the neck bolts has now pulled the neck back resulting into a perfect neck angle from the nut to the 14th fret.  But, because the playing surface from the 15th fret and above is glued down to the sound board,  the playing surface now takes a serious nose dive at the neck/body joint.  This is fairly common and is often referred to as fall-off.  In this case though, it is pretty pronounced.  Above the 15th fret, this guitar would be very hard to play....on the other hand, how many acoustic players need those higher frets?

So, the big question now is if I want to have a guitar that plays great  or if I want a guitar that has a flat playing surface from the nut to the sound hole but has a visible shim between the sound board and the fret board (of course I would do everything I can to make the shim as unobtrusive as possible).

Later.

Tuesday, February 14, 2012

Under the Bench Light

Under the Bench Light is the best title I could think of for showing readers new (and maybe interesting) guitar problems I'm currently working on.  If anyone has a better, catchier  title, please let me know.  I love constructive criticism.

I'm writing this blog from a coffee shop in Winchester VA while I wait for my car to be repaired...really do need headlights I guess.....especially in the winter.

Back to guitars.......I recently started working on a lightly used Norman B20 six string acoustic.

The Norman B20.  Relaxing before making its way to the shop.

Close-up of the peg head.  Plastic nut....I'll replace it with a better fitting bone nut before returning this guitar to its owner.


The sticker viewed from the sound hole.  Those shadows are from the strings, not prison bars.


The guitar was very difficult to play.  One quick glance clearly showed the action way way too high.

In the shop I tuned it up to pitch, strapped it in the neck jig and adjusted that truss rod until the playing surface was dead flat. Now lets take a closer look at that action.

The bad news:  The neck is way under set......way too much to be made playable by shaving down the bridge and/or lowering the saddle.  Best call in this circumstance......this guitar needs a neck reset.

No worries, it is strapped in tight. And placing the guitar in the playing position this is the best way to evaluate a neck set problem...it is amazing how much gravity affect things.

Sort of a useless pic but I wanted to show off one of my neck set measuring tools.  No guess work in my shop.  I can measure precisely how much I need to move the neck to end up with perfect neck reset.

The good news:  This Canadian-made guitar has a bolt-on neck......it was designed knowing full well that a neck reset was surely in it's future.  As a general rule, resetting a bolt-on neck is easier than a traditional Gibson or Martin dovetail reset.

So, I am not sure how the neck got this way.  It was stored for several years under string tension.  Maybe that did.  Maybe it was this way right out of the factory. And there is at least one other possibility......which would be very good news.  While the neck feels and looks tight against the heel, it is possible that the neck bolts have loosened enough to allow the neck to pitch forward.  Tomorrow I plan to remove that paper decal that covers the neck bolts and make sure they are tight.  I will try to take pics of that bolt head decal....it blends in to the neck block and hides the bolts really well.

Hope to see you in a few days.....I should have more info on this seriously unplayable but like-new guitar.

Wednesday, February 8, 2012

Open for Business

Greetings,

My name is Lee Whitehurst and this is my first post as a certified fretted instrument repair technician and guitar builder.

A little bit about me....but hopefully not so much as to put you to sleep.

After 30 years of working as a geologist and environmental scientist I decided to pursue my passion for the construction, maintenance, and repair of fretted instruments.

My life-long love for fretted instruments began when I was a teenager with an insatiable desire to play bluegrass banjo.  My first banjo was a 1972 Kay....I think I payed $85 for it.....and after a year or so of picking it to death,  I decided that I wanted an upgrade.  My father, a professional chemist and part time, but very talented and prolific furniture maker, had exposed me to the joys of woodworking.  So, I sold my Kay and bought the necessary parts to construct a 5-string banjo in my father's shop.  I played that banjo so much that it nearly cost me my college education.  My parents were sweating bullets but I managed to graduate and am a proud alumnus of West Virginia University.

After college I put the banjo down for a bit, got a job, got married, had children, and became very interested in guitar playing, construction, and repair.  Over the course of my 30 year career as a geologist, I spent a considerable amount of my free time either playing, building, repairing, or otherwise tinkering with my (and my friends') guitars and banjos.  During this time I slowly but surely accumulated a shop-load of lutherie specialty tools, a veritable library of reference materials on guitar construction and repair, and, I like to think, a considerable amount of experience.

Immediately after retiring from my geology career in early 2011, I attended and graduated from the Galloup School of Lutherie (GSL)....an internationally known school for aspiring luthiers and guitar repair technicians.  The experience solidified my desire to make fretted instrument repair and construction my life's work.

About this blog.....I intend to use it to let readers know about the current projects I am working on, how I am performing the tasks at hand, and discussions of a variety of lutherie related topics.  I hope to use lots of pictures and very few words....and will do my best to publish a new post at least once a week.

My company website will be leftbrainguitarrepair.com and is currently under construction and will be going through many modifications, so please be patient.  Once it's done, the site will contain a complete description of Left Brain Guitar Repair including a detailed listing of services and pricing.

Thanks, and I hope you will check me out next....it's likely that I'll have some photos and discussion of a neck reset I will be performing.