Ed, you are a brave man working on the gravel like that. The ranch I bought had a gravel floor in the shop and I put up with it till I started working on some old British motorcycles with unique screws some of which I dropped in the gravel never to be seen again. In one deal, I traded the labor time on a job for the rig's owner to act as general and get me a concrete floor. The concrete mixer arrived with the crew right behind, some cash changed hands and I now have a reinforced concrete floor.