Placed next to a heating radiator over the winter months the soundboard of this CF Martin D-42 collapsed.

During periods of low humidity the top will sink as shown here under the steel ruler. Fortunately on most guitars, rehumidifying the instrument will swell the moisture starved spruce and the top will rise back into the gentle dome that was formed during its original build. The problem with this one is that the moisture content had been restored and the top remained sunken and there were several top cracks

The neck, bridge and pickguard are removed to prepare for a new top.

A piece of masking tape protects the sides from the steel roller as it glides along aligning the router base.

First pass around the edge reveals the kerfing that supports the top. The sharp router bit cuts cleanly through the abalone shell.

The mahogany heel block is visible just after the router passed through. In the center is a long channel that accommodates the neck truss rod. The two circular holes were used to locate the soundboard into the correct position during assembly of the body.

The back and rim ready for the new top.

The new top fit into place. Note the two holes at the end that line up with the previously drilled holes in the heel block.

With the top glued in place the decorative abalone trim is hand fit with other contrasting strips.