I don't keep records but I estimate about 90%. All of my equipment is KD'd, weighted properly, and fine-tuned before going on the layout. Like Lester, dirt is my greatest problem. My layout is in a non-climate controlled room added to the backside of my barn, about 100 feet downwind (upwind?) from a gravel road. Spiderwebs and dirt dauber nests can appear overnight, usually in hidden spots. Fortunately this will change next spring when I build a dedicated building (air conditioned) about 200 feet further away. Added bonus: it will be closer to the house.
