Build Diary| Jack Spira | Ditson Style Part 3

I have been enthralled by Jack’s Ditson style guitars as the originals had a certain old world charm and in the latter years sounded rather good, especially with silk and steels. Their smaller size mean they could be played very comfortably with a quick response and an intimate tone.

My fate was sealed when I saw the 45 style replica pictured above. The little jewel of a guitar bewitched my eyes and senses and I began to plot a order from Jack!

We agreed on a set of specs which came very close to the originals with some modern amenites. They would have adjustable truss rods and also be X braced for light guage steel strings.

Jack has very kindly agreed to document the build process of a pair of Ditson style 1-45s: one in Brazilian rosewood and another in Acacia for us! So without further ado, here continues the build diary:

Please Click on the pics for fullsized view!

Here I am back again with some more of the Ditson..

I did end up putting the solid mahogany linings in, I figured if this one is going to be a departure from the original then I may as well depart in ways that make it my own, and I use solid linings in all my other instruments.

I make the linings of two 2.8mm thick lengths of mahogany, bent and laminated together into the sides, making a solid rim just under 6mm thick. I then scrape the linings into shape with a profile ground into a scraper.

It looks like I forgot to take pictures of this bit, oopsy.. heres a pic of the body half open that hopefully gives an idea of the linings, with some spruce splints glued in as crack stoppers..

That neck block looks a bit chunky! I should have scaled it down probably.. I used one of my standard neck blocks. Well the neck is the same size as normal really, just the body is small, so maybe it’s as well.

The next bit was making the back. Thanks again to the generosity of Dick Boak, the original Martin construction of the back is no mystery.

The backstrip I got from Martin guitar, so that was easy. All glued together with hide glue, as with the top, the Adirondack struts carved to the original specifications.

Here are some pics of that process… fairly self explanatory I hope.

So now I’ve got the top back and sides ready to assemble.

I’ve made the top flat, so no radius required on the top edge of the sides, the back edge needs to be shaped to a 4600mm radius for the curve of the back.

The top edge of the side need to have notched cut for the ends of the struts into the neck block and in the sides at the top bout, the back edge also needs notches cut for the ends of the struts…

Now the box is glued together it can be trimed and cleaned up ready for the binding…

On to the binding… which is a major part of this design.

The originals were bound with abalone purfling around the top back and sides, the shell being bordered on both sides with thin black and white lines. The original Ditson would have been bound with Ivory ( I think) and I had planned to use ivoroid binding.

When it came to it though, it occurred to me to use a wooden binding made from Satin box. Satin box is a tree that grows in southern Victoria, around the Otway ranges… so a local wood in keeping with the Blackwood, it has a beautiful bone colour that looks ivory like to me. So I put it to Terence and he agreed. I’m also using black pearl instead of abalone as per the original spec’

The black and white border lines I can make from 0.3mm thick poplar veneers, natural colour and dyed black colour. I laminate three layers together and I can then slice strips of very fine black white black strips to use next to the shell purfling.

The body can now be machined for the bindings.

First stage I’ll cut a channel on the top and back in the full width of al the purfling plus the binding, and to a depth of 1.4mm, which is the thickness of the shell..

Then the side can be machined.. first to the full depth of the binding and purfling on the side, again to a depth of 1.4mm. then a second channel is cut just the depth of the binding and to 2mm which is the thickness of the binding.

This created a stepped channel in the side allowing the two different thicknesses of the binding and the shell to sit flush ( I hope!) on the out side.

That done I move on the the end strip. This is the wedge shaped bit in the tail of the guitar body.

I make up a wedge shaped bit of Satin box, and tape on the strips of black and white lines, with 1,6mm wide strips of Teflon, which will take the place of the shell for now. I lay this assembly in place and scribe around it with a scalpel blade. Then with more scapel cuts and chiseling cut out the channel for the end strip.

The wedge can then be glued in with black and white line and Teflon and all..

When the glue is dry I can trip the wood inlay at each end and fit the short bits of black and white strips to box it in.

Now to actually put some binding on.. I’l tape a length of satin box one one edge on the top side, this is to protect the edge of the spruce from the binding string

Now on goes the binding one the other side at the top.. glue goes on, and argh! I have to hold 4 strips of black and white lines, two strips of Teflon, and one bent bit of Satin box in one hand, and the string in the other… somehow I juggle it into position and line up the mitre of the lines on the side with the end strip, then start working around, hauling it in with the string.

The black and white strips on the sides are being bent edge on and they don’t like it! They need a lot of coaxing to get them in… its gets easier as it goes along and the loose strips get shorter, then its in and one edge is bound and wrapped in string.

Around again only three more times and its done…

That’s the tricky bit over… now the laborious bit, putting in the shell. Its fairly straightforward, just time consuming…

The pieces need to be cracked on the sides to go into the curve, and carefully joined end to end and glued in

Then the sanding is also very laborious… carefully sanding the shell level without cutting itno the softer wood around..

The resulting body is nearly done! The purfling around the heel and fretboard yet to go in. I’m waiting till I’ve got the neck fitted first then I’ll cut them in.

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