Bending and fitting the purfling

You bend the purfling material as you would the ribs, using the bending iron; only the temperature should be set lower, ie. 200 degrees Celsius, depending on what the glue in the purfling can take. You can moisten the strip slightly if it helps prevent cracking. Precaution must be taken not to overheat the strip because the glue binding the layers together then melts and swells causing them to separate. If possible, try the bending on scraps first.

Also, the tight curves in the upper parts of the C bouts must be bent with utmost care as here cracking will easily occur.

On the front plate, in the upper and lower bouts, the purfling can consist of 2 parts, because at the center it will be removed anyway. The gap must not exceed 8 mm on each side off the center, though.

On the back plate, the upper and lower bouts should be made in one piece.
  1. If you haven't already, check that the purfling stock you will use is of correct width and thickness throughout its whole length.
  2. As mentioned earlier, for an easier fit, remove the edges on the bottom side of the purfling (using your scraper), making its cross section look more like the letter U. See Fig. 1 in the previous chapter for reference.
  3. Start bending the strips. Once the strips are bent correctly and they fit perfectly, choose one corner, trim the ends of the strips so that they meet and fit the corner naturally. See Fig. 1 for the detail on how the ends meet in the corner.
  4. Run your finger to check that the purfling "sits" evenly along the whole outline. If not, you may need to remove some more wood here and there. When removing material from the corners, again, be very careful when cutting next to the inner corner tip.

Gluing the purfling

If you`re working on the spruce top, you can now cut the top and bottom bout purflings in half (if you haven`t already) where the neck and the saddle will be later installed. This will make it easier for you to fit the tips of the corners right at the time of gluing. This doesn`t apply to the maple bottom plate purfling.

Have a suitable smoother (something that will allow you to push the purfling into the channel), a small hammer and a damp cloth handy. Prepare a sufficient amount of medium to thin hide glue. As always, a warm room considerably prolongs the setting times for the glue.

Work in steps, applying hot glue into the channel first and putting in the purfling as quickly as possible, because in a manner of seconds, the channel starts to swell making it more difficult to insert the strip. If that happens, use the small hammer and a smoother to drive it home. Avoid putting glue on the purfling itself as it also swells in length.

The corners are always the starting points as it is crucial that the tips meet precisely. See Fig. 2 for the gluing sequence.
  1. Work in the following order:

    a) Glue the upper left corner, put in the upper left corner "A",

    b) Glue the the upper bout, put in the upper bout "B"

    c) Glue the C bout, put in the lower corner, put in the remaining C bout "C, D"

    d) Glue the lower bout, put in the lower bout "E".
  2. Go over again with a smoother to make sure the purfling is fully in everywhere.
  3. When finished, remove excess glue with a damp towel.
  4. Check again that the purfling is fully in everywhere.

See Fig. 3 for the finished purfling.

Category: Front