WD-40

I spray the blades and deck on my lawn tractor with WD-40 after every use, so buying it by the gallon is the only way to go! It keeps grass clippings from sticking and prevents rust. After 10 years of mowing, there's not a spec of rust to be found underneath the cutting deck. However, I go through a lot of gallon sprayers because i can't find one that hold up to this stuff. Anyone know of a sprayer that can handle it (and that's affordable)? Thanks.