After all the openings have been properly calked and the logs brushed
clean, it is often desirable, although not absolutely necessary, to treat
the log surfaces with some sort of preservative material. Logwood oil is
excellent for the exterior. The colorless variety is preferable in most
cases but, if some color is desired, add just enough burnt umber, or raw
sienna paste, to give the proper shade. For interior finish, apply a coat
of clear shellac and then one or two coats of dull varnish. The trim can
be treated in a similar manner to preserve the pleasing effect produced
by the natural surface and color of the wood.