Clamp the board to your work surface with a c clamp and sand with a belt sander to remove any ridge where the tip of the table saw blade removed the wedge from your siding lumber.
How to make your own siding mounting block.
Locate step where you want your mounting block.
A random orbital power sander is the best tool for the job.
What you will need 1 x 6 pine boards 2 x 4 pine boards 1 x 2 furring strip 2 1 4 screws latex painters caulk sandpaper sander paint 18 volt drill with screw head attachment.
Set the block into place as shown and screw it to 1 2 in.
Use a jigsaw to cut a hole in the block to fit around the outlet box.
Drill and countersink pilot holes for screws in two opposite corners.
If you use a block without an electrical box shift the existing electrical box out so you can mount the fixture to it.
Siding mounting blocks ply gem mounts and blocks create a smooth stable surface for installing accessories on your home from lights and doorbells to electrical outlets water faucets and more.
Sand both faces of the board thoroughly with 150 grit paper.
Constructed from high performance polymers our vinyl siding mounting blocks withstand extreme weather and hold their color for the life of your home.