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Monthly Archives: January 2010

Making rosettes for a classical guitar (4)

All that remains at this stage is to cut the inner and outer circles to make the annulus of the rosette. I start by drilling a hole in the centre of the work piece…

… and then use a Dremmel mounted in a shop-made jig to cut the circles. (More details of the jig are available in the ‘Tools and Jigs’ section of this site.)

Here are the two rosettes that I’ve talked about in early posts in this series cut out.

And here are a few more. Going clockwise from top left, they’re made of English yew, laburnum, spalted beech, spalted crab apple and mulberry burr.

It’s probably best to leave them attached to their base until you’re ready to install them on the soundboard but, as you can see from the two rosettes at the bottom, I don’t always heed my own advice.

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Making rosettes for a classical guitar (3)

The rosette below is made from laburnum, arranged to show the striking contrast between the light coloured sapwood and the dark heartwood. It’s rather more complicated to make than the spalted beech rosette shown in the previous post and a fair degree of accuracy is needed throughout.

The starting point is a small piece of laburnum. This one has been air drying for a couple of years and I reckon that it should be pretty stable by now. I’ve scraped off the wax that covered the endgrain while it was drying.

The first step is to decide how many individual sector shaped pieces to use to complete the circle. I’m planning to use 20 for this rosette, which means that the sides of the billet must be planed to converge at an angle of 18°. That’s hard to manage on the bench top and it’s worth making a cradle to hold the wood while you plane it to size and shape. Go slowly and carefully because it’s important not only that the angle is right but that there’s no taper along the length of the piece. In addition, the width must be right so that the line between the sap wood and the heart wood ends up where you want it to be in the finished rosette.

Having planed the wood to a near perfect prism, it’s sliced on the bandsaw.

The pieces are numbered as they come off, so that they can be put together again in consecutive order.

Here the rosette is being assembled ‘dry’.

It may be necessary to make some fine adjustments with a shooting board and a block plane.

Here, the first piece is being glued and clamped into position on its plywood base. The base has been marked out in pencil to aid positioning of the individual pieces.

As the pieces are glued into place, the rosette nears completion.

Cleaned up and levelled with a finely set block plane.

Making rosettes for a classical guitar (2)

One of the rosettes is going to be a replica of the one used for the zebrano guitar that I made last year from this remarkable lump of spalted beech.

I used a bandsaw to cut 2 thin (3mm) slices …

… and trimmed and book matched them to create a symmetrical pattern.

A card with a rosette shaped cut out helps give an idea of what the finished rosette will look like.

I use veneer tape to keep the two pieces in registration while they are glued to the base that I described in the previous post.

Clamping up.

Out of the press and ready to be planed flat and cut into shape. The veneer tape comes off easily if a little hot water is brushed on.

The next post will be about the construction of a different sort of rosette.

Making rosettes for a classical guitar (1)

Last July I wrote a couple of posts about making a guitar rosette from spalted beech. But I missed the opportunity to photograph some of the details of its construction and, since I’ve been making some similar rosettes recently, I thought it might be useful if I had a second attempt at explaining the method.

For reasons that I’ve discussed before, I like the visual effect of rosettes made by inlaying wood with contrasting colours or a striking figure and often use this technique when making guitars.

These rosettes are made from at least 2, and usually many more, individual pieces and I’ve found that it’s much easier to assemble them accurately on a base of thin birch plywood (0.4mm or 0.6mm thick*) than it is to inlay them directly on the soundboard. Because the plywood is so thin, it too needs a stable base during the assembly process. But, of course, it must be possible to remove this base when assembly is complete. I start with a square of 6mm MDF, a similarly sized sheet of clean paper and the square of  plywood that will be the permanent base of the rosette.

One surface of the square of MDF is given a thin coat of hot hide glue.

The sheet of paper is then smoothed down…

…before adding a second coat of glue…

Glueing up 3

and the layer of plywood.

The whole thing is then clamped up in a nipping press and left to dry overnight.

If you don’t have a press, a flat board and a weight work just as well.

The point of the paper and the hot hide glue is that, after it has been assembled, the rosette is easy to detach from the MDF base. In another post, I’ll show the next stages of the process.

*This sort of plywood is used by model makers and, at least in the UK, is easily available from the sort of shops that supply materials for people who build model aeroplanes.

Last instrument of the decade

Below are a couple of photographs of my last instrument of the noughties, a copy of a violin made by Guarneri del Gesù in 1742. It’s very slightly smaller than the original with a body stop of 190mm, and a string length of 320mm. I think it’s going to be a powerful instrument but it will be a few weeks before it gets a proper trial because the violinist for whom I made it recently broke her right arm – unpleasant enough for anyone, but doubly unfortunate for a string player.

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