I got a walnut carolina slab from Dave in February 2015 that arrived with what looked like a small scratch/defect in the corner and didn't think much of it.
You can see it on the leftmost corner of the 2nd picture:
This is a photo I took today of the defect. It doesn't seem to have widened or lengthened, but a thin line is visible on the underside of the board which makes me pretty sure it's a crack (end checking?) that runs through the width of the board.
Should anything be done to prevent this crack from expanding? The board is already oiled and waxed regularly.
Can I repair it somehow?
Any advice is appreciated.