Jerry:
Great looking bridge!!
Kind of stealing the thread, but I want to respond to HJ’s powder coating suggestion:
I know lots of folks mention powder coating and some metal structure vendors provide powder coated products. I have personally used powder coating extensively in both indoor and outdoor industrial equipment. We have used commercial coating vendors and I have an Eastman DIY powder coating setup here in my shop. I use an old kitchen oven to fire the coating on parts of limited size. I just want to mention that there are some potential problems with powder coating’s use.
The process uses electrostatic charge to attract a coating of very fine powder to the target surface. The ‘green’ coated part is then ‘fired’ at moderate temperatures to produce a uniform tough coating, similar to paint.
There are two main problems: 1. While the powder is pretty uniformly attracted to the flat and outside parts of the target surface, inside angles usually have a much thinner coating, which can lead to rusting through at these points; 2. Any tiny pinholes in welds are not coated and are really subject to rusting through, showing up as pinpoint rust spots.
We have completely eliminated the use of powder coating on the fabricated frames of cleanroom equipment. In that case, the tiny amount of rust bleeding from the welds can act as a contaminate in the various processes the equipment is designed for. We went back to the ‘old fashioned’ technique of two part epoxy paints.
In various outdoor equipment, the rusting in the inside angles (same as are formed by the various bridge girders) can wind up being both unattractive and causing general failure of the coating. Once again, we have gone back to either plain rust resistant paints (for general equipment applications) or two part epoxies for items like the R/C fire fighting vehicle we are currently prototyping. Powder coating is very good for relatively smooth and continuous outer surfaces, but we have really backed away from it on complex fabricated / welded items.
We really prefer Sherwin Williams Polane Polyurethanes. They are available in quite a few variations, including two part, single part, water based and ultra flat finish. It is easily workable and only requires a spray gun. Very forgiving in application and really weather and rust proof.
I apologize for the interruption, but hope this is of help. That bridge would be beautiful in either flat silver or flat black!!
Happy RRing,
Jerry Bowers