I, like many builders, like to put a cross-gain patch along the inside of the side where one is going to cut a side sound port. The cross grain patch strengthens the side, and helps prevent any splitting problems that might arise from cutting a hole in the side. I make my patches out of thick veneer which bends easily because the grain is across the curve of the side.
For additional strength I now run the cross-grain patch all the way to the edge of the side, so that there is the maximum amount of cross-grain gluing area. I put the patch in, and cut the sound port, before the kerfed lining is installed. Not having kerfing along the edge of the side makes it much easier to trim the inside of the sound hole edging veneers as they are installed.
I have found a very fast and easy way to notch the kerfed lining to account for the cross-grain patch veneer using the disk sander. The disk is a little proud of the case edge so it is possible to simply put the kerfed lining against the disk to take off a little on the inside, and leave a nice sharp edge. Takes seconds and makes a very neat job.
