Guitar#29/7

ribs in mold with neck block, tail block & lining for top in place

ribs in mold with neck block, tail block & lining for top in place

After bending the ribs I had to trim them to length and fit them into the mold. The mating ends have to match perfectly so the seams are tight and the ribs remain in the same plane. Once all is measured and dry fit the interior blocks are glued in. I did this one at a  time. Notice that the ribs are spread. They require a bit of force to push them to the inner faces of the mold, not much but enough to keep everything square. It always takes a few tries and some checking to ensure that this step keeps the ribs from tilting  off plane.

Next I glued the linings onto the edge that will be the top. They are glued a trifle proud of the edge and afterwards planed to level. Once this was done I dry fit the top. The main objective here is to have the top fit tight to the ribs without obvious gaps. Once that was ready it was time for the next big step – attaching the top to the ribs.

ribs in mold and sitting on a cantilevered workboard

ribs in mold and sitting on a cantilevered workboard

I use a cantilevered workboard, which is a piece of plywood in the shape of the mold. The mold sits on this, and the top will be attached and roped into place.

top dry fit to ribs before gluing

top dry fit to ribs before gluing

Once it looks like everything is fitting together perfectly it’s time to glue. With the ribs and mold sitting on the cantilevered workboard I apply glue to the linings and clamp the neck end down. The main thing now is to be sure the top is centered on the ribs. Of course I have made some pencil lines for this, but once the glue begins to grab you don’t have very long to make adjustments. There is a lot of surface area here and the glue starts to hold quite rapidly. Having dry fit the whole thing several times it makes the process a lot smoother. After first clamping the two ends it’s time to rope.

ribs and linings with glue applied, ready for the top plate

ribs and linings with glue applied, ready for the top plate

Roping is an old term from the days when they actually tied the tops on with rope. I use a giant rubber strip, which is simply a long piece of inner tube made from a truck tire. It’s one inch wide and very long. I start at the waist, because this area also has to be bent down to contact the ribs, due to the arch in the top plate. It goes down easily, as the top is fairly flexible at this location, having no bracing there. Once it’s all roped up the job is done. I’ll leave it a good few hours just to be sure it holds well. Note that I removed the clamps at the ends once the roping was underway and the top was stabilized in place.

top plate roped to rib assembly with long rubber strip

top plate roped to rib assembly with long rubber strip

1 Comment

Filed under Guitars

One response to “Guitar#29/7

  1. Chiam Halfman

    Looking good!!!

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