New answers tagged hanging
If you use long enough lags to get a good bite into the stud, your first proposed method should be fine. If the "lever" action is high enough to snap a lag bolt, then it will be strong enough to snap the 2x3 as well. From a strength perspective, it doesn't matter how long the lag bolt is - the torque and shear at the junction of the wall/bracket interface ...
Look at French cleats. There are wood and steel options. Make sure you anchor them adequately in the wall as well as in the shelf back.if your shelf is hardwood, you can make the top wedge part of the shelf itself. http://www.newwoodworker.com/frenchcleat.html
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