I'm still messing with these new window sills. It is a stupid little job that involves a little ingenuity to overcome past poor workmanship.
I had to make the stool for one window run out of two pieces of oak and when I did a dry fit, I found they didn't line up across their surface. I cut them to hit a high spot, but the twist in the top plate did me in. Keeping the front in line with each other was easy as I am adding a 1 x 2 to the bottom front edge to give the sill a thicker appearance. The problem was the back of the joint.
The easiest solution was to add a piece to the back of the stool. The problem was, I no longer own a router and I had never done something like this by hand.
I ended up using my Veratis Small Plow Plane, adjusting the depth of the blade down with each stroke to cut deeper each time. I then cleaned it up with a chisel and laid in a piece of pine, planing it down flush when the glue dried. I didn't even bother to try to square up the ends. Instead, I just curved them so it wouldn't look like a dog's breakfast.
It worked, but it was a bit of a female dog to do. I think there must be an easier and more accurate way to do blind rabbet like this, so again, if anyone has any direction they can give me with this, it would be greatly appreciated.
The learning curve with handtools is unbelievable.