Q: After sanding the glue lines flush in a glued-up panel, they were smooth for several weeks. However, now they have crept up slightly. I can't imagine this will keep happening, do you think? What I was also wondering is how helpful mineral oil will be in minimizing the change in MC. I appreciate your advice.

A: Apparently, the wood is drying and shrinking, as wood does not change its size or shape unless the MC changes. At this point, I believe that the glue lines are quite rigid, so that as the wood around them shrinks a bit, most of this wood is free to shrink. However, the glue lines are too rigid to shrink, so they will appear to stick up above the surface.

Once the entire piece reaches its equilibrium and final MC, you can sand it smooth and you'll be OK (unless you have large MC changes after sanding).

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