Dealing with Pitch Pockets
Here's a nice handful of workable methods for preventing bleed-through of pitch from pitch pockets in softwood lumber. January 8, 2010
Question
I am trying to seal or stabilize a pitch pocket that is in VG Fir. I have tried Bondo, as I thought it would set fast enough to prevent it from bleeding through, but it ended in failure. This is an exterior door that is to be finished with a low sheen in black. Any ideas out there?
Forum Responses
(Finishing Forum)
From contributor J:
Bondo is actually too hard and will start to show cracks around the repair after a few heating/cooling seasons as the wood moves. Glazing putty - a mix of linseed oil and chalk or ground limestone used to set window glass - has a long history as an exterior wood filler under paint.
From contributor R:
Why not route it or drill it out, put in a "dutchman" and proceed with your finishing schedule?
From the original questioner:
Thanks for the response. I did proceed with the dutchman. Sometimes it just looks you in the face and you don't see it in front of you.
From contributor T:
Had a large pitch pocket on the underside of a table, and with a sharp knife, cut out the hard and soft areas, then used hotmelt glue, filled area and smoothed out. No more pitch. The glue dried clear - you really have to look for that patch.
From contributor I:
Another is to use West System. Clean out the pitch with solvent and then fill. If you are clear coating, you can tint the epoxy to make it look like wood grain.
From Professor Gene Wengert, forum technical advisor:
The pitch that would be soft at room temperature can be evaporated by heating the area to 160 F to 180 F for several hours - maybe 12. The pitch that remains will be very hard at room temperature and will not bleed. Normally, this heating is done during kiln drying.
