Monday, April 16, 2012

Repairing Lutes and Guitars

It is inevitable that my instruments are damaged in one way or another. I expect to have one in my shop at any given time, but my clients are having a run of bad luck over the last few weeks. Here's the casualty list, all with loose bars caused by age or careless baggage handlers; 1983 ten course, baroque guitar, large Schelle model theorbo and most recently, as a rush item, a small theorbo with .... loose bars.

The story of the ten course is interesting. It was built by my early apprentice, Bruce Duncan. Bruce went on to study in England and returned to build lutes. This was one of them. He is no longer involved with lutes but stills builds early instruments - analog synthesizers.

 The damaged lute has had its belly lifted numerous times over the years. This procedure takes a toll on the wood fibres around the edge where it is attached to the side ribs. This is a photo of the area above the bridge on the treble side. You can clearly see the damage that repeated repairs has caused. I did not look forward to removing the belly again but I decided to take it off and then to completely renew the edge. Here is how I did it.

There was damage similar to this around the rear edge of the belly continuing up to the third bar on the bass side. The procedure to repair this type of damage requires that the inside damaged edge of the belly be removed to a uniform width and depth and then filled with a splint of wood of similar grain direction and structure.

I removed the three harmonic bars and the finger bars that support the underside of the bridge and made a template to guide my router. This is a handy machine. It is smaller and more manageable than many routers but more sturdy and accurate than the Dremel Tool. It is called a laminate trimmer and its industrial use is to remove the overhanging veneer or laminate that occurs in the fabrication of counter tops, shelves, etc. The 1/4 inch thick  plywood template  allows the circular base of the router to move freely, smoothly and precisely around the edge of the belly at a set depth. Just enough wood is removed to expose the underside of ebony half binding (left side of above photo) that encircles the edge of the belly.

Then I cut thin pieces of spruce and shape them to fit snuggly in the routed channel. I glue them in place with hot hide glued, secured with painter's tape and sandwiched between layers of plexiglass. The inserted pieces of spruce are allowed to dry then they are levelled flush with the surface of the belly and the harmonic bars and fingers are glued back in their original places.

Here is the result after everything is done. This is a lightly built lute that gets a lot of use. I think it is good for another 30 years.

To a greater or lesser degree I carried out this procedure on the other instruments. It is frightening to use the router for such a delicate operation. But if care is taken and the set-up is well thought out it does the job very nicely.

All of these repairs have taken time and a toll on me. Although they are necessary and appreciated I would rather be building new lutes. 

I have started the mould for a triple nut baroque lute after the A. Jauch in Copenhagen. Very shortly I will begin to describe building the mould and then follow through with posts concerning the construction of the entire lute. 

The last week of April I'll be at the Boston Fine Arts Museum to measure the Checchucci guitar. 

No comments:

Post a Comment