I'm in the process of making some shelf brackets and I'm wondering about the strength of my design. If I use a triangle shape made from three jointed pieces, will that be stronger than a solid piece of wood for holding the shelves up? What are the considerations I should keep in mind for strength?
3 Answers
It's true that glue is stronger than the lignin that binds wood fibers, but a glue joint won't be as strong as solid wood. Depending on how well you craft it, the joint could be a weak point. For your brackets, since they'll bear loads, having them all aligned in the right direction is crucial for strength. Ideally, the fibers should be continuous for the most effective support.
Using a triangle made from three jointed pieces is generally a good idea. One solid piece can have issues due to the grain direction, which might cause it to split. With three pieces, you can align them with the grain, making for a stronger triangular shape.
Keep in mind that in a shelf bracket, the break usually happens at the wood near the glue joint rather than at the glue itself. Make sure to focus on surface prep and proper application while gluing. A well-done joint can hold up well, but it still won't be as strong as solid wood under stress.