See here.

Likely overkill unless you're operating a commercial carwash.

Thanks Worthy ! I have contacted American Garage Door Supply and they replied very quickly. They have 2 that they recommend that are both air powered operators ... Supralift II for $1400 that is a "jackshaft" style operator ... and NuMax for $2200 that is a "trolley or drawbar" style operator. They both are completely designed to be corrosion resistant (and used in commercial car washes).

I also called Overhead Door Co. They recommend their Genie SilentMax 1000 or 1200. It has a belt drive (instead of chain that will rust) and the track is aluminum (instead of steel). It sells in Home Depot for about $200. According to cust service, this is the same model as their professinal model IntelliG 1000 or 1200 that sells thru their dealers.

What I have right now is a 1/2hp LiftMaster chain drive that is already rusting and hindering the movement in barely over one year of use. The main problem is with the track that the trolley travels on ... it is already getting so rusty that it creates tension on the travel and activates the safety feature which of course stops the door. Also, it binds up. Our installer recommended that we spray it with Liquid Wrench (not WD40) and it helped at first, but not so much anymore. I also sent an email to Chamberlain / LiftMaster, but they have not responded yet.

Who else manufactures garage door openers that I can contact ?