You can use two for the flat column and three for the corner column. If you have any other inquiries about our Master Flow products please call Technical Services at 800-211-9612.
The only way to get this on an existing post is to cut the post as close to the surface as possible. Unfortunately, if there's more than 2 posts, you'll have to cut them all and remount as many as you cut. Usually these are for a new installation, but can reinforce a rusting fence post (if you cut it first)
I would use silicone caulking. It is quite flexible for filling the gaps. It sets up and it still stays flexible and it can be painted over to hide the gaps.
Didn't see white
It is straight rail, not angled for stairs
no bought single piece.