Wiped On Poly And Sap Help!

darita

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Joined
Jan 23, 2007
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462
I built a bench out of clear Douglas Fir and have been trying to get a finish on it.  After several coats of GF Arm R Seal, wipe on poly, sanding with 400 between coats, I had what I thought was an acceptably smooth finish for the bench.  I have to say that I had problems with little nibs of dust that roughened up the finish, so I had to sand and recoat, but it worked.  When I was done, I had to put the bench outside, in the sun, for a couple of hours.  When I brought the bench inside, I noticed some patches has become rough again.  After rubbing the rough areas with my fingers, I noticed the smell of sap on my fingers.
This has never happened to me and I don't know what to do.  The clear Doug Fir seemed dry when I purchased it and it sat in my garage for about a week before I began machining it.  It all seemed dry when I worked it.  So now, what can I do?  Is this typical of Doug Fir?
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Darita:
Nice looking bench.

Fir can be "pitchy".
Some of the pores contain sap and as soon as the wood warms up (sun) it starts to run, that is what you are finding.
Sand and then clean the area with a good solvent - acetone, lacquer thinner (MEK) or turpentine let dry and then coat with some shellac.
Recoat with GF Arm R Seal.
 
I'm thinking if I sand and recoat, it will happen again.  Is there something I can just clean the sap off of the finished poly with?
 
Try "Goof Off" or any consumer gum cleaner on small area that's not visible.
Hopefully it won't cloud the Arm R Seal.
Tim
 
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