Mo Deck works. Available many places. Below is a lionk to see it at Tractor Supply Co.

Here is a link that might be useful: Tractor Supply

I use Fluid Film - available at John Deere dealers. I give a good coat before winter storage also to help prevent rust.

You also need to blow it off after every use on the top side (with air not water, this IMO keeps the dust/dirt from soaking up moisture and bubbling the paint eventually which will lead to deck erosion not to mention the ebrasive action of fine dirt/sand on moving parts. Maybe wash it once or twice a season, blow the water of with air, and wipe it down, but don't actually spray the spindles. IMO if you do this you LT and deck will look like new 10 years later

Ok.how do you get to the underside......I have a winch hooked to the top of the garage door.........on my old mower..I hooked to a strap and up it went,,This one will scratch the lights.....will a Bumper hold......$30?

Has anyone sprayed truck bed liner on the underside of a mower deck to keep sand from eroding the deck when cutting yards near the beach ???

wright - very few coatings of any kind can withstand a constant sandblasting. May also want to often check your deck blades condition as sand will wear them down quickly - particularly hi-lift blades with wings.
Best to run blades w/o a hi-lift wings - for both the blades and deck's sake.