Finishing the interior of a hollow vessel. Is it crucial?

[Glen Blanchard]

How important is it to place a finish on the inside of a hollow vessel? I'm not asking in an esthetic sense, but rather wondering if having finish on the outside of a piece but not on the inside would pose a problem. Would this be ill-advised at it might lead to sucking up moisture or does it have absolutely no affect beyond the esthetic?

[Scott Hackler]

Glen, it's not "important" for a structural sense. No more than a wooden box that only has been finished on the outside (see jewelry and humidor boxes). From an esthetic sense, sometime I will pour in some poly, tung oil or what ever... slosh it around and pour out the extra. My general rule of thumb is if I can see easily into the HF or if I am going to pierce the heck out of it.... finish inside. A small enclosed HF with the usual 1/2" -5/8" hole.....likely not applying finish to the inside. That being said, I will still wipe finish inside the hole as far as the paper towel soaking with the finish reaches, if I am not applying finish to the rest of the interior.

[Eric Gourieux]

What Scott said

[Joe Meirhaeghe]

I don't know if it's really necessary or not but I always put finish on the inside of all my vessels. Having done flat work for many years where the rule is what ever you do to one side should be done to the other to keep the wood so it will absorb humidity equally, yielding a more stable product.