After rebuilding hydraulic cylinders, and discovering dirt gets past wiper ring, damages o ring, I started experimenting. First I used a plastic tube and covered it with a tube sock. Then I learned cylinder rod protectors are sold commercially made of canvas or Kevlar. Went to town and bought water proof cloth, but I could see small holes in the fabric. So I took a yellow plastic table cloth to make first sock. Second sock out of waterproof cloth, which is less likely to tear. I use hose clamps at both ends to hold socks in place and keep dirt out. Anything has to be better than letting diry come in contact with rod.