When you use the chop saw. You turn the blade backwards to get a smoother
cut. Notice
the siding on the far right has holes where
you nail it so the siding can expand and does not buckle.
Here is the inside and outside corners, you
can see the slots where you nail. If you drive the nail all the way
in, the siding has no room for expansion.
This tool is made to make slots in the vinyl,so when you slide
the vinyl into the piece on the right it catches
and holds on to the siding. The piece on the right goes on top, and
the last piece is cut and fits in.