Wednesday, 7 October 2015

Removing a fingerboard from guitar neck

After playing about with an "electronic guitar tutor" idea, it seemed a good idea to get the design off the table and actually onto a guitar. We've a few guitar parts knocking around at Nerd Towers, including an old Marlin Explorer, and some spare guitar necks (the origins of which have been forgotten, but there are two or three old body-less guitar necks hanging around too).

Now the usual approach when it comes to removing something from something tends to be a mallet and chisel (failing that, a flat-headed screwdriver, claw hammer and a crowbar or level). This time, we thought we'd try to be a bit smart about things.

A lot of people online have reported success using a household iron, a palette knife, and lots of patience. We've got all three. Ok, two out of three - but, as Mr MeatLoaf might say, two out of three ain't bad. And an iron and a palette knife were easy enough to get hold of. In fact, the palette knife is more like a large carving knife. But it's old and blunt, so it'll do. One out of three ain't bad... ok, one out of three is pretty poor.

Anyway, whacking the iron up to full steam and  placing it directly onto the frets got us going quite quickly.

Lots of people online say you need to do this really slowly. Take your time. To get to the 12th fret (less than half way) in about an hour is considered good going. Whether it was our super-awesome Russell Hobbs iron, or just sheer brute force, we made much faster progress than that!

After the fingerboard started to lift, things slowed down a bit. It became apparent that we weren't heating the fingerboard quite so well as we did at the start.

As the fingerboard is lifted up by the knife, it curves up slightly. So placing the iron "longways" along the fretboard means it's not making contact with the board itself. No worries - just turn the iron around, to get a better contact with the frets (and the underlying board)

We left the iron in place for less than a minute, and found that our knife slid up two or three inches at a time, very easily. An hour to get halfway?! We we on track to have the whole thing done inside about ten minutes.

With a resounding "crack" the knife split the glue on the last two frets and the entire fingerboard came away, in one piece. Amazingly, there was no damage to either the fingerboard, nor the guitar neck. The fingerboard was already surprisingly flat; we clamped it to a flat surface while the wood cooled down, just in case, but it retained its shape perfectly.

Unfortunately, not everything was undamaged.
The sudden release of the fingerboard sent the knife flying off towards the headstock...


Maybe these online luthiers have a point about taking your time and going slowly. Because this really hurts. And with "ferric fingers" (ferric chloride can discolour your fingernails for three or four days at a time) let's hope it doesn't get infected! With the fingerboard removed (and thumb taped up with plenty of tissue paper - there were no plasters immediately to hand) we tested the PCBs for a fit.

The LEDs line up nicely with the fret positions. The PCBs are slightly wider than the neck, so when we get to BuildBrighton tomorrow night, we'll have a go at sanding them down on the belt sander, to get them to fit the width of the neck.

Then it's just a case of bolting the neck back onto the guitar body and embedding a microcontroller (and character LCD display) into it. For a "let's see what we can do with these bits we've got left over" kind of project, it's been quite satisfying. And there's a very real danger it might come somewhere close to getting finished too. Maybe.