Welcome to the Newschoolers forums! You may read the forums as a guest, however you must be a registered member to post. Register to become a member today!
Drill up from the bottom, its alot easier ive done it with all my rails, for supports. build the frame of your rail first and add PVC last. On the ends of the rail i suggest 45 degree supports attaching to the outer most leg and the base of the rail, it will be increadably sturdy that way. (if you have access to a tool the will actually cut exactly 45 degrees other that a saw and your eyeballs)
with 4X4's you should just screw them the the underside of the rail (the other side of the 2X4 that the PVC will be on) if your going to use 2X4's as legs than make supports like i did see below
No the metal corner brackets arent needed but i had them laying around so i threw them on there and it crazy sturdy. obviusly this rail is tiny but it was a mock up i made with left overs for a friend. if your rail is longer the angled supports will need to be longer