This student cello had a significant issue—a large hole in its plywood rib, with fractures spreading through its thin maple veneer. Given the instrument’s value, disassembling it for repair wasn’t practical. Instead, I developed a simple yet effective solution. By creating both an inside and an outside mold, I was able to pull the fractured plywood back together. Using four small holes and strong string, I tightened the molds, sandwiching the broken wood securely in place. Below, you'll find a series of photos showing the step-by-step process. Unfortunately, the final image is missing, but the end result was certainly an improvement over a gaping hole in the rib!
Here are the general steps.
- Glue the cracks that radiate out from the hole.
- Create the outer mold and the inner mold. The inner mold has a little more curve which applies pressure to the broken pieces.
- Drill 4 small holes that line up with both the inner and outer molds.
- Place the outside mold on the rib and drill through the rib.
- Feed all of the string through the outer mold, the rib holes and the inner mold holes.
- It ends up having two string that sinch the inner mold, the broken rib parts to the outer mold together.
- Glue and clamp.
- Remove the molds. The outside mold just comes off, the inner mold has another string so I can pull it off of the inside of the rib.
- Glue the very thin maple vanier back onto the plywood rib.
- Fill a little bit of the missing chards and use small dowles to fill the 4 holes.
- Touchup the varnish a little.
|
