Wednesday, December 17, 2014

The finish line.

Here's a late-'90's Guild F47 that came in for some finish work recently.  It's got some localized pick wear.
Pretty vigorous strumming!  It extends into the spruce, and it's worn deeper in the soft summer growth, leaving the harder winter lines standing proud.  What's nice is that the abraded surface is fairly fresh and clean looking.

This is a chip on the lower bout.  This seems to be nitrocellulose lacquer, and it's very thin for a production model guitar. (That's not a bad thing). You can't see it well in these photos, but the entire surface has that sunken washboard effect one finds in nitro that has been buffed soon after spraying. This chip has been exposed to the elements for much longer and the spruce has oxidized quite a bit.
It's a multistage process.   I start with a thin coat of cyanoacrylate to seal the wood surface, followed by light washes of dewaxed shellac tinted with dye in an effort to match the darkened lacquer.  This is a guessing game. The tendency is to go too dark, and one has to remember that the new lacquer is going to age and darken as well.  In the end, I'm happy to subdue the raw white of the abrasion.
Next comes another layer of cyanoacrylate, and finally several coats of lacquer, sanded and leveled prior to hand-rubbing with polishing compound. The lacquer keeps sinking into the canyons between growth lines!
I didn't use any color on the chip, because I had a hunch about the surface oxidation. The longer it's exposed to air the darker it gets.  Have a look at the joists in a the attic of a fifty year old house and marvel at the complex chemical reaction! After a century they're like dark chocolate.   At least this appears cared-for, and it's not prone to further flaking.
 The area next to the bridge fared better.  The lesson being: if your guitar gets a scrape it's easier to disguise if it's tended to sooner rather than later.

Friday, November 7, 2014

A blast from the past.

One of my first steel string guitars has resurfaced and I'm pleased to offer it for sale.  It sports serial number 005, and it was made in 2003.  It was my third steel string instrument and it has some interesting features.
It's an amalgam of  Dreadnought and J-Series design features.
The scale length is 25", the body is 15-3/4" wide.
The nut width is 1-3/4".
The soundboard is Engelmann Spruce.
The back and sides are East Indian Rosewood, as is the fretboard.
The finish is French Polished shellac over polyurethane.
The most unique thing about this guitar is that the neck joins the body at the 13th Fret.  Gibson used this most notably on the Nick Lucas Special model, and also some Roy Smeck guitars. When designing this instrument with a "short" 25 inch scale I reasoned that moving the body joint up a fret would keep the bridge back towards the center of the soundboard.  
Just as an aside, I'm a big fan of short-scale steel strings. The trend has moved toward 25-1/2"+ lengths in the last decade or so in most of the Asian imports. To my ear they produce a strong fundamental note but it's a little inert. The shorter scale seems to bring out more high partials and. chords sound more interesting. They also have a different feel to them.
The binding is cherry and there's a thin and simple purfling of maple and walnut. There are some wear marks and bruises in the finish, and two cracks (in the finish only), one below the bridge, the other along the bass side of the fretboard.  I repaired these eight years ago after the guitar spent some time next to a heating register during the winter months... (Keep your custom guitar in its case and use a soundhole humidifier!!!  Grumble.)  I think the checks were in the polyurethane I used for the sunburst and it was a little mystifying, because the soundboard itself was undamaged. I put some cleats under the area just to be on the safe side.
 The neck is a robust 1950's style C-profile, and the nut is a generous width.  The neck was made from very pretty African mahogany.  (Wistful sigh. That was a good board... I wish I had more of that mahogany...)  The tuners are decent. I can't remember what they were. The neck is attached with a bolt-on arrangement, but also glued in place. 

I used hide glue to put the body components together.  I'm tempted to reach in there are scrape away the little squeeze-out line next to the back graft.  I'm also tempted to start making doodles on my labels again.
The soundhole rings are strips of maple and walnut veneer. The bridge is just a little wider than standard, and the saddle is very tall.

How does it sound?  My camera isn't excellent, but I made a little video.  I think it's held up well. It's fun to play.

Monday, September 22, 2014

Recent Projects

I'm getting around to photographing some projects and adding a gallery section to my website.
I thought I'd post them here as well.

 Uketopus, concert-size ukulele with hand-painted "embellishment":
 Five-course Baroque guitar after Antonio Stradivari, 1700:


Five-course A-style Mandolin with fanned frets:

Saturday, August 30, 2014

Gibson ES-335 Headstock Repair

This is a Gibson ES-335 which is feeling a little under the weather.  Some time ago it suffered the classic Gibson headstock fracture, presumably when it hit the floor.  It was dealt with by the repair department of a well-known music shop and unfortunately the repair didn't hold.

Why?  There's a lot of surface area and all things considered it was a clean break.  It's very difficult to tell from the photos, but I suspect the joint was clamped tightly together and thin viscosity super glue was wicked into it.  This probably wasn't the best choice of adhesive. Cyanoacrylate glues are very brittle and don't have great shock resistance. Hide glue is also brittle but it also has much greater cohesive strength.   I now have to deal with a joint that has its mating surfaces sealed with plastic.  Epoxy seemed the safest choice.
The black fiber headstock facing was kind enough to bend rather than break and hold things together. The fracture runs right through the truss rod cavity, and I was sure to back the nut off and lubricate it well before applying glue.  I also used some tape in there to try and keep infiltration at bay.

I used a high-quality epoxy with a relatively low viscosity, so I had to mask things off carefully.
Clamping cauls are padded with cork and protected with packing tape. This is important because enough pressure is applied to dent the surface of lacquer! The previous repair guy left a divot right behind the first fret...

Things came together nicely, and it was time to add reinforcements. I don't usually use them on first-time breaks, but this guitar sees a lot of hard playing and this being the second repair, I thought they'd be added insurance. I mapped out the truss rod and figured out where I wanted them to be.
Here's my low-tech spline cutting jig.  It's just a platform that's sized to fit the base of my laminate-trimmer with no play. It allows 1-3/4" of travel. The depth adjustment on most laminate trimmers isn't very precise - the router isn't held perfectly concentric with the base so when you increase the cut the channel often ends up with stepped walls.  I eliminate that problem by using inserts which raise the base off the jig in 1/8" increments.  I make a pass, stop the router, remove an insert and repeat.  It works well.  To do the cutting I like a high-speed steel spiral upcut bit.  These don't last as long as carbide, but they're far sharper and less prone to chipping the finish on the margins of the cut. They also make excellent plunge cuts in hard material.

The jig in place.  The surfaces are padded, and there's a 15 degree bevel on the right side.  I measure the depth carefully so as not to rout completely through the headstock. (That would be baaaad....)
Here are some splines from African mahogany. I take time to make sure they fit really closely before gluing them in with standard wood glue. Carving away the excess comes next, which is fun!  The goal is to match the contours as closely as possible without damaging the surrounding lacquer.  In the end it's important to know when you've reached "good enough".
A dab of color, a smear of lacquer, a little buffing by hand and it's ready to play again.

Friday, March 7, 2014

Deep cleaning.

Here's an old fiddle that needed a little TLC. (It didn't want no scrubs, just gentle solvents...)   It's been resting for decades following a celebrated career acting as accompaniment to dances and parties.

The fiddlin' days are long over, but it deserves to look its best.  There's a serious split under the tailpiece.   It's covered in a mixture of rosin and... something else.   I believe at some point in the 1940's or 50's someone decided to make it shiny by brushing on a nice coat of boiled linseed oil.  The problem with linseed oil is that it oxidizes for decades and eventually turns coal black.   It took quite a lot of elbow grease to lift it off the original varnish using judicious applications of acetone to melt  a little bit before quickly rubbing it away with clean cloth.  A polish with some spirit varnish and it's ready to go back on display!

Saturday, March 1, 2014

A Banjo Ukulele

A short video describing a recent effort to put a venerable old instrument back into playable condition.

Thursday, January 23, 2014


Some recent works-in-progress.  Flamenco with subalpine fir top / Alaskan yellow cedar body on the left, Classical with Western Red Cedar top / Indian Rosewood body on the right.  The five-strut arrangement with diagonal "treble" bar relates to some work I did from a Miguel Rodriguez plantilla some years back. I really liked the sober character it produced in the basses.