On Monday, December 11, 2017 at 9:30:01 PM UTC-6, wrote:

Often flooring is coated with a silica based clear coat, which is
supposed to resist scratching (and sanding ;-) but I think it's all UV
set and can only be done in the mill. If the flooring is scratched
now, I don't think there is anything you can do to prevent it from
happening again (other than getting rid of the toenails). The dark
stain makes scratches more apparent, too.

All true. And nothing is harder than the specialized, factory set finishes.. Somewhere there is a graphic of those types of finishes that show their abrasion resistance, and it is almost off the charts. You can't compete with a simple air dried application, and not even with the catalyzed stuff.

Robert