Have you tried Linseed oil for rust prevention, if you have you know to be careful of stroing the rags after application to avoid spontaneous combustion accidents...and/or ClearSeal 5000 which gives shine without penetration of water. It needs a long time to dry though, incase you don't know about these 2 already.

Theres a wax call rennasance wax which is good for interior finish im not so sure about exterior it was devrloped by the british museum and totally synthetic so it dosent go brown like natural waxes like bees wax.

Believe it or not, Thompsons water seal has been keeping one of my customers outdoor steel protected for 15 years. He says he has to apply it every year or two. I live in tulsa ok. so the weather might be different where you are and have some bearing on how well it works, I don't know. Hope this helps you.

Johnson's Paste Wax is big out here in the Pacific northwest. I use it regularly for items where I want the raw steel effect. It provides a really nice luster, and, depending on the piece, lasts a couple years outside before the rust really sets in.

Thomas Taranowski
Artist-Blacksmith
tom@baringforge.com
http://baringforge.com

.........thought I'd add powder coating to the discussion. You'd have to take it to a local powder coater, however, it does pretty good for long-term outdoor use. My local powder coater charges $35-$50 for something the size of an average chair................I usually use clear which allows the natural steel to come through nicely.