There is also occasional
bleeding from the natural migration of resin or pitch, which may appear
on the surface as beads of clear or colored resin exudate. This generally
is limited to woods dried at temperatures too low to evaporate lighter
components of the pitch. It is common in resinous species such as pines
and douglas fir, and other soft woods especially around any wound areas.
Resin or pitch bleeding typically occurs on surfaces warmed by sunlight
or other sources of heat. Each bead or streak is from an individual resin
canal and will appear as scattered discrete deposits. Stains appearing in
larger areas may be the result of wounds that occurred in the living
tree. Pitch exudations can be removed by using mineral spirits, however
there is a strong possibility that pitch exudation will reoccur.