Expert: Eileen Cronk - 9/28/2007

Question
Hi Eileen,
I saw your response to a knotty pine cabinet question, and hope you can help me as well. My wife and I are refinishing knotty pine paneling for our basement. We are sanding them clean, staining and then using 2 coats of a flooring-grade polyurethane. This wood is about 60 yrs old. Something is bleeding through the poly coats on some of the boards, a white material that follows the grain in places. Is this common for older wood? Is there anything we can do to prevent it?  

Answer
Hi Rick
Nice to hear from you.
What you are experiencing is the reason I dislike pine.
This stuff will be pine pitch or resin.
Hard to believe that after all these years its still bleeding through.
Of the Canadian woods I have worked with, only pine does this so its not common for all older woods, only pine.
And it will bleed through 6 coats of poly.
My advice is to discard the boards that are doing this or use them in an inconspicuous area because as far as I know there is no cure for this.
Good Luck and interesting question
Eileen