Sunday, August 19, 2012

New Upright Bass Fingerboard

Last month, I realized I was wrapping up my first year as a professional instrument repairman.  It had been a great year, regular maintenance repairs, brace repairs, crack repairs, and some neck resets and broken headstocks too.  I really hadn't had the chance to do anything outside of the realm of what I learned at Red Wing.

While I did learn how to make a violin fingerboard, and knew how to keep my block plane sharp; making a new bass fingerboard from a chunk of wood the customer brought in with their instrument was going to be a process in itself.

After waiting as long as possible for the piece of cherry to acclimate to the shop's humidity level, it was finally time to put the bass on the bench and take off the old fingerboard.

Note: This bass had a cherry fingerboard (a very thin one), using only North American woods was a choice by the builder of the bass, as well as a preference of its current owner (who is a very good friend of mine, and the shop).  The old fingerboard was warping, and really couldn't be dressed at all, so the new fingerboard was to be much thicker; at the same time this would make the instrument more comfortable for the player.

Supposedly this heat blanket was originally designed to keep space craft warm, then it was sold to luthiers to heat ribs in the bending process.  Here it's working hard to loosen up some glue.

This picture was taken hours into the process.  The use of aliphatic resin glue, and (surprise) locating pins, made this task tedious. 

It came off pretty clean.  Now it was time to start turning the large piece of cherry into a fingerboard.  Much of this was done by Tom, who basically got the wood into the wedge state for me.

I copied the two radii of the old fingerboard, made templates and here I'm starting to put that compound radius on the new fingerboard.  When your plane cuts ebony cleanly, cutting cherry just puts a smile on your face.

So here the radius is roughed out, the next step was putting in the decorative swoop at the end of the fingerboard, and then waiting until it's glued on to do the final dressing.  I believe the state it's in now is basically a fingerboard "blank."

The customer wanted to re-use the old bridge.  Even though it had height adjusters, the new fingerboard's thickness would make the projection too high.  So Here I'm planing the neck to compensate for that.  I think about .75mm was all that came off the overstand. 

The glue up went really nice, and I didn't have much material to remove to bring the fingerboard flush to the neck.

After gluing the fingerboard on, I suspected it would move a little bit.  So I just got the fingerboard flat, and then I'd check it the next day, and flatten out any movement.  I think about 5 or 6 days after glue up, it was stable enough to do the final dressing; which is what's going on in this picture.  The customer has a really aggressive style, so I went with a bit more scoop than usual, and optimized it for the 3rd position.


And at this stage, it's basically done.  We can now see that decorative swoop I had talked about.  It's based on an Upton Bass "Hawkes" model (which is the customers other upright). 

I failed to grab a photo of the instrument strung back up, because minutes after it was done, it was in a car headed for a gig in Brevard.  Also, about two days after leaving the shop, it was being played outside on a humid day that was about 95 degrees.  Talk about testing it out!