Sunday, May 3, 2009

Installing the Purfling

After a few weeks of being busy with legal work, dealing with my broken digital camera, and learning that hand cutting a purfling channel for the first time isn’t so easy, my first violin has purfling installed.

To install purfling by hand (instead of using a router), a double bladed marker, a sharp knife, and a sharp purfling pick are needed:


The first step is to set the two blades of the pufling marker the appropriate distance apart (in this case, 1.3mm) and the proper distance from the edge of the plate (in this case 4mm) and scribe two lines around both plates.  It is important to keep the marker perfectly parallel to ensure that the distance from the edge and the width remain constant:

With the lines scribed, they are then deepened with a sharp knife.  I used numerous light cuts to keep the curves intact, the walls of the channel perpendicular to the bottom of the channel, and to avoid accidentally widening the channel:


When the knife cuts are sufficiently deep, the purfling pick is used to remove the wood between the knife cuts and to create a level bottom of the channel at approximately 2mm deep:


Here is the top plate with the purfling channel cut on the upper and lower bouts:


When the channel is finished, strips of purfling are bent using a hot iron to the shape of the channel:


Then, the corner mitres are cut and the purfling is dry fit.  This being my first attempt at making good purfling corners, I admit that I am not that happy with the corners (for one thing, they exhibit the beginner characteristic of being too long), but the good news is that I have learned from my mistakes, and the corners on number two will be much better:


With everything dry fit, sections are lifted up, glue is applied to the channel, and the purfling is hammered into the channel (note that on the top plate, the purfling doesn't need to meet up perfectly at the top and bottom joints because they will be removed for the neck set and the saddle).  The purfling that I was using was 1.3mm, rolled in a pasta roller to approximately 1.1mm, which then allows it to expand and fill the groove when it comes in contact with the moisture and heat from the glue:


When the glue has dried, the excess is removed with a gouge:



Then, a channel is created using chisels and a scraper.  The same process is repeated with the back plate.  Here are the finished products:



The next step is to finalize the arching on the plates.

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