Each bracket has 3 holes (two at the top, one at the bottom) and I'd like to align them to give me a proper horizontal (w.r.t. gravity) alignment. What's a reliable way to tell me where to drill? I only have a rather short level. The shelf (just a wood board) I'm trying to mount is approximately 4' long, the level I have is at most a foot long. In the past I've tried "extending" a level line by moving the level along but results have been... mixed.
A helper would really help with a 4’ board
- Screw one bracket into the wall (bottom hole only) 6” in from one edge where you would like the shelf
- Place the other bracket 6” in from the other end
- Place the shelf on the brackets and keep the brackets flat against the shelf
- With the level on the shelf, raise or lower the bracket to find level
- Screw in the second bracket in the bottom hole
- Screw in the other holes and attach to shelf (ensure the shelf is centered first).
- Maybe add a middle bracket, 3’ is a bit of a span depending on what you are putting in it