We have an oak barrel for use as a planter for some wysteria on a stone patio. I would like to know what should be done to preserve it.
The barrel is an old rum barrel but not guaranteed to be watertight.
Advice seems to be mixed on whether they need to painted with varnish or sealant. I've put what I've learned so far into an answer in the hopes someone can improve on it.
Life expectencies seem to range from 2 to 20 years.