I own a cabin that was remodeled, and the former owner used a couple of old barn beams that look
great. They were never sealed or sanded. -- still can find some bird do do on them. -Well the problem is
what they call powder post beatles. These will leave very small holes in the wood about 1/32" in dia.
When they feed on the wood they leave very fine sawdust the we find on the coffee table ect. --- Each season there is a hatch of adult beatles that can fly, they don't bite and we just vacuum them up, they only hatch for about two weeks. ---I have watched an episode of this old house where they discused the same problem. They talked with an entomologist about how to rid the beams of the beatles. --- They desided to heat the beams to 160F and keep that temp for 24 hours so the heat would penatrate the beams. They built a vis-screen tent out side and with a salamander heater with a thermostat they did it. --Made sense to me. ---- I have thought about starting up the wood stove and stripping down on a hot july day!! Ha --Good luck