My plan for trimming this area is to make two (or more) passes with a router. The first operation will be with a rabbit bit, the second with a flush trim pattern bit (top bearing). Of course the ends of the cut will have to be squared up with a chisel. One problem I see with this approach is that the rabbit bit takes off 3/8” of material, I was thinking ¼” would be plenty. The wall thickness in the area to be cut is 1”. Does it sound feasible to attach 1/8” aluminum across part of the wall thickness to act as a shim under the bearing of the rabbit bit thereby decreasing the depth of the cut to ¼”, then removing the aluminum shim and making the pass with the pattern bit. Or would it be just as well to take off the full 3/8” and make up the difference with trim and rubber seal?
I’m sure if Steve Fredrick sees this he will advise me of a better way. I hope…
