Derek McCormick’s Violin Blog

Making a violin and other violin-related topics

Jointing the Front

front

This is the spruce which I will use for the front. When cut from the log it ws a single wedge-shaped piece which was sawn lengthwise and opened like a book. Like all my wood I got this at Bertrand Michaud's sawmill (le Bois de Lutherie) in eastern France. This wood was harvested at least 15 years ago when the sawmill was at La Chapelle-sur-Furiuse (his stamp is on the wood), before his move to Fertans. It is a beautiful piece of fine-grained spruce with about 170 years growth at high altitude in the Jura mountains.

planing-collage

The first stage of joining these pieces is to plane the jointing surfaces absolutely flat and at 90 degrees to the lower surface. For this I use my Lie-Nielsen plane and a "shooting board". It is very enjoyable to work with a good plane and a well-honed iron - the long ribbons of shavings roll off the wood as thin and transparent as onion skin! It is vital that these two pieces of wood will meet perfectly along the whole length and width of the joint. In the finished violin the wood will be less than 3mm thick along the length of the join, so any tiny gaps could obviously have disastrous consequences.

joint02

The jointing method that I employ is centuries old and is known as a "rubbed joint". One piece of the front is held in a vice and freshly made hot hide glue is brushed over the surface. The second piece is set carefully on top and slid firmly lengthwise back and forward. After a few seconds you can feel an increased resistance as the glue begins to "grab". This is the time to stop and leave it overnight.

resin-pocket

After jointing I planed down both surfaces and came across a resin pocket. Theyt are not uncommon and there is no way of suspecting their presence. At any rate they are not a problem and often they disppear during subsequent carving. Sometimes they persist but they are easily removed and repaired without tonal or aesthetic detriment. Stradivari found one when he was making his celebrated "Messiah" violin and if you look carefully at photographs (or the original in the Ashmolean Museum) you can see his repair on the upper treble bout of the front. In the present case the pocket is less than 1cm long and not very deep so it will probably disappear as I arch the front.

front01

My bandsaw has fairly narrow "throat" so I have to se a sort of "jigsaw" technique to saw the outline of the front.

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April 7, 2009 Posted by | (10) Jointing the Front | Leave a comment