So more patching and repairs.
The rear segment of the lid had developed a number of cracks at some point. After the finish was removed it was obvious that some previous cracks had already been patched. The cracks are not necessarily a weakness in the lid – many appear to be surface cracks through the veneer.
With some vertical pianos (with two piece lids), the rear segment can be removed. The rear segment of this particular model McPhail piano is glued down, so repairs must be made in place.
Some of the cracks are small enough as to not cause visual problems. The larger, darker cracks will need cleaning up and patching.
We use a shop made cutting tip that allows us to carve a groove along the crack. The tool allows us to make the groove the correct width and depth for patching.
Once the crack has been prepared we can cut a veneer patch to the correct length and glue it in.
Once the glue dries we can trim and sand level.
A little paint thinner lets us see how it will look with a finish.
As can be seen, these patches will also need to be colored to match. With such thin patches it is best to wait until the wood has received its first sealing coats before matching the colors.
The piano also had some more sever veneer damage along the lower edges on each side.
As with patching descriptions in previous posts, the first step is to find a portion of repair veneer closely matching the same grain patterns.
We cut a tracing of the patch.
Now we can clean up the area for patching. The substrate veneer was very damaged as well so we needed to make up a new substrate. The substrate is basically a layer of veneer that runs at a right angle to the surface veneer. Its purpose is to create a smooth flat surface and, very important, protect the surface veneer from wood movement (i.e. the swelling and shrinking of the cabinet wood).
Once the substrate is glued in we scrape the surface flat.
The new patch gets glued in. There was a need for a couple smaller patches as well (as seen on the photo above).
Once the new patch is stained to match, we can begin graining in to help disguise the seem. Graining can also be used to help create effects for better matching.
Not completely finished but this photo gives a good idea of what the final work looks like. While the seems are still a bit visible in this photo – once completed with a sealer coat and a bit more touching up, we think it will be pretty hard to notice.
Just to compare, here is the original damaged area.