Q: We are making some red cedar furniture and want to know what preservative to put on the wood to extend its life.

A: This wood, the red-colored wood called heartwood, is naturally decay and insect resistant. Any brush or spray treatment would not add substantially to the longevity of the material.

The sapwood (white-colored wood) has little natural decay resistance; however, a brush or spray treatment will not protect the wood substantially, especially around the joints where water can be trapped. So, I do not suggest such a treatment.