I've acquired an unfinished fir planter box. I intend to stain the exterior. Can anyone recommend a non-toxic sealant or coating for the interior to help retard rot?
I've seen recommendations for Linseed oil (boiled or raw), various Tung oil products, and about five bio- or plant-based products. I'd like to avoid urethane.
Does anyone have experience with any of these products? Thoughts?
https://gardentabs.com/plant-s...
Thanks for suggestions.
