I was flattening a pine plank for a live edge table top and found a large hidden pitch pocket. It's about 3 1/2" long x 1 3/4"wide x ~3/8" deep, oval shaped. I got most of the pitch out and plan to fill it back in with epoxy. Do I need to completely dry out or remove the remaining pitch (mostly a thin layer on the surface) or can I just pour the epoxy over it? If I need to, how do I dry it out|? I tried scrubbing it out with turpentine with moderate results. Any suggestions short of carving it out?
Yes you might try carving it out. I wouldn’t expect the epoxy to adhear to the cells if there is a layer of pitch over it. You might try a heat gun to soften it and make it easier to wipe and dilute.
I think I can usually cut and lay in a wood patch that looks better than an epoxy fill. I find a piece with matching grain, cut it down to about 1/4” thick. I thencut out a shape a little larger with a slight bevel that I sometimes hot glue or just hold to outline with a sharp knife, then router out close to the line. It’s more accurate to chisel out to the scored outline. Then with the beveled edge I get a snap fit that is hard to see when it’s sanded flush.
I think the uncured resin will be a good solvent for pitch and the result be unpredictable. The epoxy will likely react with the pitch chemicals altering the cure and I suppose altering bond strength. Unless I showed the pitch had no adverse effect on the result I hoped to achieve I would remove all of it. Seems like selecting a replacement piece of wood should be considered.