What is a joint sink and will the DEA prosecute me if I’ve got one?
Michael Dresdner: I presume you are talking about the problem that occurs when a long grain joint sinks and puckers after glue-up. Here’s the scenario:
You put water-based adhesive on the edges of two boards in order to glue up one wide board. You clamp away, and soon the glue is dry. In reality, some water has gone into the wood on either side of the joint and the area is slightly swollen, even though the glue is dry. Now you plane the board flat. In a few days or weeks, you notice that the flat board is now sunken right around the joint. The reason is that you planed the wood while it was retaining water and was swollen. Once the last of the water flees the wood, and that takes several days or more depending on the thickness of the boards, the wood shrinks down to its original size, only now you have planed it “flat” while it was swollen. The result is what looks like a sunken joint.