bobnap wrote:
I have a 2005 Jayflight 31BHS and the painted white wheels are badly rusted. I've considered trying to scrape and paint them but think I'd prefer to purchase new rims. We camp on the beach so I'm hoping someone has input regarding what type of rims are most corrosion resistant in that environment. In addition I am unsure what size rims I need based on a tire size of ST225/75R15.
Bob,
When I replaced the tires on my previous RV (Jayco HTT) I decided to change the rims also, not because the white rims were rusty but because I thought they were ugly AND I wanted to upgrade the load capacity of the tires to match the 3500# of the axle.

Anything exposed to a salty sea air will corrode. The rims shown above are more resistant to corrosion (I believe) than the steel ones and if one wanted one could coat them with clear for an added level of protection.
Based on your tread width, I would think that a rim 7.5" - 8.5" would work. However you need to look at the rim and tire together, and ensure that not only the rim is the proper width but it is strong enough for the pressure load the inflated tire would impart.
My 2 cents.