Oil finishes give a sheen to wood, and some also protect it by polymerizing
in the surface of the wood and hardening. Pure oil finishes will not give a
high gloss; oil is often used as a base finish for a wax surface.

Several possibilities exist if you want to stick to using oil exclusively.
There are three basic categories of oils that are commonly used on wood:
vegetable oils other than nut oils, nut oils, and mineral oil. Oils from
animals (lard, bacon grease, etc. are not used because they will go rancid
on the wood. The same applies to vegetable oils other than nut oils, but
less so. These need to be "renewed" now and then, as someone else
mentioned, or they will go rancid -- either start smelling badly or
solidifying unattractively, or both. Frequent re-application of these oils
will prevent this. Mineral oil (the pharmaceutical kind) is sometimes used
on items that will have contact with food. Mineral oil does not "harden" as
the other oils do, so there is little protective value in it. However, it
is perfectly clear and imparts no color to the wood, merely the darkening
of some woods by virtue of wetting.

The nut oils, primarily tung oil, linseed oil, and walnut oil, don't get
rancid or cloud over with time. Each has its advantages and disadvantages.
Note that peanuts are not nuts, and therefore peanut oil is in the non-nut
vegetable oil category.


Walnut oil is used where contact with food is in prospect. Its protective
qualities are less than the others, so it's usually reserved for this
purpose. I haven't used this oil myself, but I understand it imparts a
darker color to the wood.

Linseed (flax seed) oil is a traditional finish in Western furniture,
having been supplanted for this purpose by varnishes and lacquers, which
for a harder, glossier surface. Its protective quality (i.e. the hardness
of the polymerized surface it forms on curing) is greater than that of
Walnut oil. It imparts a yellowish color to the wood. Use boiled linseed
oil, not raw. The raw oil is for paint thinner and for conditioning
leather. "Boiling" linseed oil also involves some magic other than just
boiling it for a while...buy the can that says "boiled".

Tung oil (also known as "china oil") gives the hardest polymerized surface
of the oils considered, and imparts a lighter yellowish cast than linseed
oil does. Many "Tung Oil Finishes" are available, though, and most of them
contain driers and resins, i.e. varnish, that will change the nature of the
surface quite radically. If you want an oil finish, be sure the can says
"Pure Tung Oil". However, if you want a little gloss (which I assume
wouldn't be very good on a Go board), pick a tung oil/varnish blend.
"Polymerized Pure Tung Oil" is Tung oil that's been partly cured so that it
takes less time to set up on your wood.

As to which is "the best" oil finish for a Go board, my answer would
be..."it depends" I like the mellowness of the linseed oil finish in some
circumstances; I think that for something you're going to be staring at for
long periods of time, like a Go board, you'd want a mellow, unassertive
finish. The Tung oil, while glossier, is more protective though, and
requires less maintenance and less attention during the finishing process.
With linseed oil, the rule of thumb (which has been given variously by
different authors) for applying a finish is "Once an hour for a day, once a
day for a week, once a week for a month, once a month for a year, and once
a year for the rest of your life". With Tung, you can skip everything
between "Once an hour for a day" and "Once a year".

A paste specifically for oiling boards can be made as follows. Heat equal parts paraffin (wax) and mineral oil in a small pan, stirring the mixture together as the wax melts. Pour into small container and let cool. You will have a paste wax mixture that can be applied for extra long-lasting protection.

Anything to take into account when storing, other than temperature?

Yes, humidity. But it's nonsense to worry about that unless your goban costs a few grand.