Several months ago I turned this lignum vitae lidded box. The first thing I noticed after completing it was how quickly the wood changed color in the sunlight, going from a just-turned honey brown to a very dark brown in only a couple of hours.
I finished the box's exterior and interior in the same way, going through the grits up to 600 and then finishing with mineral oil and beeswax (or possibly carnauba/beeswax mix, I don't recall).
Now, after three or four months being indoors (on a table by a sunny window), I opened the box to find the inside surface covered in fine, silky white fibers:
...as you can see from the photo above, the fibers aren't stuck strongly to the surface and bunch up easily when touched by a finger:
I sometimes finish pieces with 0000 steel wool (but I don't recall finishing this one in that manner), so I held a strong magnet to the fibers to see if they would react, but nothing happened. Here's a closeup of the fibers after I wiped them out with a rag:
...from the way the fibers bunch, it seems more like a spider-silk material than a cotton-fiber material, but either way I'm puzzled. Why would this only appear on the inside, and not the outside, of the box? Will it keep growing back after I wipe it away? Has anyone any ideas what might be happening here?
Thanks in advance!