So that’s what’s under your fretboard!

I thought that I’d show you this photo; it makes sense of what I do with my archtop mandolin necks.

You’ve got the head, neck and two parts of the fretboard extension, each one glued to its neighbour. Under each of the two mahogany capping strips, is a length of rectangular section carbon-fibre. The CF runs from under the head overly as far as is practical in to the fretboard extension.  So firstly, the carbon-fibre unifies all the different elements of the neck. Also wherever you have a joint you can get movement, so the idea of the carbon-fibre is to stiffen the neck and stop any distortion along its length.
The capping strips are bonded to the CF with epoxy and I use them so the fretboard can be glued to the neck’s flat surface with Titebond.

The devil is in the detail

Does anyone really give a monkey’s about how the finger rest/pick guard is attached to my mandolin? But as they say “The devil is in the detail” and there is a lot of planning and careful work in this apparently simple fixture.
Firstly, the fretboard extension has to made, no two edges are parallel which makes things a bit tricky!

Once it’s been made, it's temporarily held in place with a wood screw, then a piece of maple (which will eventually be fixed to the underside of the finger rest) is shaped too.

 I use brass machine screws to attach the finger rest to the instrument, so threaded inserts are fixed into the side of the fretboard extension. As I mentioned, no two edges are parallel, so it’s clamped to angle plate to ensure that their holes are drilled true.

Then a couple more test fits before the fretboard extension is finally glued to the mandolin.

Those two pesky little pieces represent a good day’s work! Yep, “The devil is in the detail”

Bindings and purflings

All the work on the archtop’s bindings and purflings has been completed and here are some photos for you. You know about the rope around the top plate. 

The bindings are maple from the same board as the neck and around the back and sides runs a single dark green line.

 Must say that I’m very happy- all that fettling, well worth the effort!

Rope!

With the archtop’s body together, the next stage is to work on the bindings and purflings. Like most luthier’s, I cut the rebate channels for the bindings and purflings with a router. I don’t know if I’m getting fussier in my old age, but these days I seem to spend more and more time fettling the rebate in search of the prefect fit!

 I’ve always liked “rope” purfling and have successfully used it on a number of guitars, but never on a mandolin.  I like to have the purflings and rosette matching and the curves on my mandolin rosettes are far too tight to bend the rope purfling around. Anyway, I had a lightbulb moment, “the archtop doesn’t have a rosette!” So, I thought that I’d use rope on this one.

Here you can see the purfling being held (whilst the glue dries) in place by some StewMac Orange Multi-Purpose Tape. It’s the first time that I’ve used this tape and I’ve been happy with its performance so far. It might not sound like a big deal, but getting just the right tape is important- tough enough, right amount of tack etc….

 

And with the purflings in place, I go through my usual mummification process to get the maple bindings glued on.

Archtop; the story so far

The video says it all...........

Top Plate III

As promised, I’ve got the braces/tone bars fitted to the top plate. The fitting takes quite a bit of time and the one thing that you can’t do is run out of patience. This is how we start off…………

As the inside of the top plate is curved in every direction, you need a jig to ensure that the tone bar is always held in exactly the same position.

The first step is straight forward, roughly mark it out and then cut it.

And then it’s a painstaking procedure of sand, check, sand. The best way to check for a good fit is to use feeler gauges to locate any gaps. It took me about 1 ½ hours to get this one fitted and then using the same jig it was glued in place.

The next day, after allowing the glue to dry overnight, the process is repeated for the second tone bar. And on the third day the bars are shaped and the top plate fitted and glued to the rim.

Top Plate II

So here is the top plate fully shaped and with the sound holes cut and bound. I feel quite strongly that the holes should be bound; it helps protect the softwood edges from accidental damage, strengthens and helps to lessen any risk of cracking at the holes, stop moisture escaping via the end grain and looks jolly nice too!
Next week I’ll get the top braced and we can think about assembling the body.