Install Corner Joint for Composite Top Rail

What happens here

For outside corners of the composite top rail, cut each piece with a 45-degree miter. Bring the two mitered pieces together, ensuring they form a perfect 90-degree corner. Drive a screw diagonally through the joint from one piece into the other, effectively pulling the two sections together and creating a tight, flush seam. Once secured, the screw hole can be filled and sanded for an invisible finish if desired.

Goal: Join two miter-cut composite top rail pieces at an outside corner for a seamless appearance.