Ed of H, and another Bass Repair Odyssey (Shop Thread)

[cozmik_cowboy]

OK, thanks, Gregory - now I need a six-string version of 91-16...................


Peter (who never remembers to take his Beano before coming here)

[edwardofhuncote]

Okay, I spent some time this weekend ‘cipherin’ (hat-tip Jethro Bodine  ) on how to go about fitting this mostly square block precisely into a place with two compound radiused surfaces and two obtuse angles. How precise... probably dealing with less than 1/16" tolerance at any point. Came up with these two templates, one the shape of the top of the new block, and the other the shape of the bottom. Though it may look like they’re the same, they really aren’t… it’s just not easy to photograph it 3 dimensionally (without a distance perspective) and show that, but once they were drawn out 2 dimensionally it’s easy to tell. (I make up words only when I have to) 
 
So once I had the templates fit, I stuck them to the top and bottom of our new block using the marked centerline of where the new dovetail mortise will eventually be located. Then, using a good ol’ red Sharpie pen, plotted out the hard cut-line and hatched-in what wood will stay. This is like the parable where the violin-maker doesn’t really carve a violin, he just whittles away everything that isn’t a violin.   
 
There’s still going to be a lot of hand-carving with scrapers and sandpaper to get the final fit perfect… even after we’re done with the bandsaw and belt-sander, but this oughta’ get me pretty close. The pictures explain it better... more exciting details coming later. 
 

[rnolan]

Hey EoH, neat !!

[edwardofhuncote]

 Another banjo/bass thread derail… I’m trying to get a few projects cleared out to make room for stuff coming in this Fall.



One of them is a 1926 Gibson Style 2 “ribbon-flange” banjo, (more on that later) the job; a tenor-to-short-scale-five-string conversion by using the original tenor neck. We did this by sawing the neck on a diagonal, from the center of the heel to the 4^th fret, then grafting in a ¼” slice of maple and re-shaping, thus making the neck ¼” wider from the 4^th fret down to allow for the fifth string. Before that, I had steamed off the original fingerboard, and carefully saved the old “Nick Lucas” pearl inlay to be re-used in the new fingerboard. This banjo being a Style 2 was a fairly simple model, but we decided to dress it up a little with this pearloid binding instead of bland white or cream colored binding. It’s just delightfully gaudy in an almost art-deco way. Remarkably easy to work with too… hard to tell how old this stuff is. You have to be a little careful, as it will catch fire if you get a little too over-zealous sanding or trimming it with the Dremel tool. (voice of experience) It’s best to hand-shape it with a file. I'll post a follow-up picture of this one, but it's going to be overwith pretty quick... it'll get refinished this weekend, back to the infamously bland original Sheraton Brown, probably rubbed out and re-assembled by mid-week, tweaked on for a couple days and delivered next weekend.   
 
We’ll get back to the American Standard week after next, (it’s about to get exciting) but here’s a couple illustrations of the aforementioned gaudiness... do not try this with your Alembics. Please. 
 

[hammer]

Gregory


Your repair notes are doing a great job keeping me entertained as I sit here in Minneapolis for a flight to Baltimore that's now been delayed for over three hours. And the detours are great.

[edwardofhuncote]

Pictures Monday Brian, but after working on it most of yesterday, it's now been fretted, finish sanded, and assembled for a trial run. (would have strung it up, but had to quit and go clean up for a gig.)

I'll do all the pre-setup today, work out all the kinks, then disassemble again for finish. If all goes well, this one will be done on or about Thursday.

[edwardofhuncote]

 Continued from last week… trying to keep the posts shorter and let the pictures speak for themselves.



Let me start by saying how much I despise fretwork. It might be the underlying reason I spend so much time on fretless instruments. That said, a banjo needs frets, (or at least this one did) and thankfully there were only 18 so it went mercifully quick. Since the neck was bound, each fret end had to be nipped and filed so that it would overlap the binding – that was really the only hard part here.


Here’s also a couple pictures showing how I spliced in a piece of maple to make this neck wider to allow for the fifth string to be added. The heelcap hides the joint from the rear view, but see how the old maple neck is stained from the purpleish-brown varnish makes a kinda’ stark contrast to the new piece? It won’t matter since I’m going back a shade darker, though I may have to fudge a little to make the splice less noticeable. Gibson called it “Sheraton Brown", and it’s a popular color they used on their lower-end models well into the late 1920’s. 


I re-shaped a recycled bone nut… there’s this little box in my shop full of scrap pieces. I never throw stuff away… and sure enough, there was one in there just the right size. Only took a few minutes to fit it in place. Since this banjo is now a five-string, it needs a fifth string nut too… my Grandfather was a locksmith, and had drawers full of these little brass tumblers – perfect for this job.


There was an extra trick to mounting the tuning pegs. For some reason, and I really don’t know exactly why, Gibson headstocks are tapered so that they are thicker by about 1/8” where the 1^st and 4^th pegholes are drilled than at end of the 2^nd and 3^rd. Some of their guitars and mandolins are like that too. Anyway, I had to do about a 1/16”counterbore on the 1^st and 4^th pegholes from the reverse of the headstock so the pegs would come through the front far enough to thread the bushings on. One word about that job – SCARY, even with the right tools (brad-point bit and a drill press) one little slip, and *snap*. Start over. That fifth string peghole is a tapered bore too. That’s hand-fit with a tapered reamer.


Finally, here it is, all assembled on the bench. I strung it up yesterday to set the action and make all necessary adjustments. It only need some fine tweaks, so tonight we’ll take it all back apart and start the finishing process.


If all goes well, the next installment will be in Technicolor…
 

[edwardofhuncote]

One more... I texted this silly action picture to the soon-to-be-custodian of this little banjo with the caption:

IT WORKS... IT WORKS!!! 

(Steve Martin was right - you can't be sad when you're playing a banjo)

[elwoodblue]

That's a pretty cool trick, with the diagonal and all.
Very well done!!
 Has Steve Martin ever been wrong? 

[cozmik_cowboy]

Mad props!  That is excellent!

Peter

[growlypants]

Way to go.  Awesome!

[edwardofhuncote]

Took a few more pictures during disassembly yesterday evening…

This first set shows how a typical Gibson coordinator rod attaches the neck to the shell (round part, also called the pot assembly). The most critical part about this is the fit of the neck heel to the shell, but secondary to that it’s also important not to put the shell in a bind by using the coordinator rod as a turnbuckle to adjust the action. Long term, this warps the shell into an elliptical rather than round. Dad refers to this step as setting the shell up “neutral”, putting no stress in any direction, only counter-acting the stress of string tension. Also note the old The Gibson - Kalamazoo, Mich. label inside the shell… I could never understand why they drilled right through that nice gold leaf label for the bracket-shoe lugs. Anyway, yeah that’s how a banjo neck is installed if you ever need to know. 
 
Another illustration – remember how I told you the headstock was tapered? Here’s a picture showing that, and another showing that terrifying counter-bore on holes 1 & 4 to make the pegs work. I've had to do this routine before, and it just scares the crap out of me each time. You may wonder why not use the original pegs… I do have them -they were the old screw-mounted Grover “two-tab” tuners- those things are geared like 2:1, just one step better than friction pegs. Banjos are hard enough to tune (jokes aside!) without mechanics working against you, so I saved the originals back for a future vintage restoration project, and replaced them on this one with some much more practical vintage reproduction pegs. They have period-correct knobs, and came geared 4:1, and with a small diameter shaft, so the headstock needn’t be re-drilled. You can see where I've filled the old screw holes... they'll be hidden under the finish later. 

 

[edwardofhuncote]

So after disassembly, I masked off that wonderful faux pearl binding with some regular old masking tape, loaded up my trusty old Badger airbrush and sprayed an alcohol-based dye to approximate the purpleish-brown color of that old finish on the shell. It took a while before the splice began to disappear, but eventually the saturation won. The alcohol carrier evaporates in minutes, leaving behind the distorted color. After buffing off the little bit of fuzz with some 0000 steel wool, I shot two coats of acrylic lacquer over the color to seal it in, then peeled the tape off. After cleaning up a couple tiny spots where the color bled through the tape (it always does) I shot two more wash coats over the whole of both pieces. That's when you see the true color pop back out, as if still wet. 

Since the humidity here is about 200% right now, and lacquer loves to attract moisture, I brought them inside to cure overnight, and went to bed.
 
With apologies for the grainy pictures, (they were compressed for texting... kind of my own factory-to-customer thread  )  Here’s what they looked like on the kitchen table this morning. I'm pretty thrilled with the color match, and the overall texture. This one is going to finish out nice and vintage-y.

 

[ed_zeppelin]

I caught Cletus plonking on his banjo and staring at his orange juice, and he was squintin' so hard his forehead looked like the furrows when he got drunk and decided to make a corn maze right in the middle of the field. (It worked, too. He never did find that tractor again.)

I said; "Cletus, what the hell are you doin'?" He pointed at the orange juice container and said; "shhh! It says: "CONCENTRATE!"

[peoplechipper]

Nice work! I love these threads!

I remember reading years ago that George Gruhn claimed that the old tapered headstocks were less likely to break compared to the later ones; he claimed that the taper made the headstock slightly more flexible and less likely to break, if I recall correctly...Tony.