Question
I have had a complaint about pitch bubbles appearing through the finish on a Douglas fir door. I am not a pro finisher so I thought I'd ask if anyone knows the best way of cleaning this up without damaging the finish. The door is finished with Sikkens.
The root of the problem is that all my material is kiln dried, and the pitch should be set, not leaking through the finish. The door is exposed to direct sunlight. Is the pitch ever completely set, and was my wood not dried at a high enough temperature? Is this a common problem, and what do other people do to deal with and solve this?
Forum Responses
(Finishing Forum)
From contributor C:
Kiln dried does not mean the pitch has been set. If you search the knowledge base here, I seem to remember a temp of 180 degrees for 24 hours is required to set the pitch.
The problem is that the pitch will cause a breach in your finish which will allow moisture to get under your finish and peel it from the inside out. Then it is very hard to tell the customer it is not your fault. With that said if you remove the finish and hit the area with a heat gun to warm the sap then get into the area with a cardiac needle and try to draw out the warm sap. Once that is done then inject acetone into the pocket and flush out the area repeatedly.
Once you have flushed out all you think you can and let the solvent dry then inject the pocket with a thin mix of epoxy. But first try to get the door company to take back the door and charge them for the finishing of the new door.
This can contribute to the bleeding because of the wood trying to equilibrate, which means the bleeding will not stop until the wood has equilibrated. Also, if the lumber has been dried at 19% then most likely the pitch has not been set.