Rust as protective coating on bridge steel?

[Jstpssng]

On a discussion of steel in the long ago past, I vaguely recall a comment that bridge steel is designed so that it gets a veneer of rust which then protects the metal. Does anyone know about this, or is my memory just going whacky? (again )

 

[Industrial Toys]

There used to be a product here fromt the Steel Company of Canada STELCO, called Stelcoat. It did not require any surface treatment and just rusted. In fact, they clad their Office Tower in Hamilton Ontario with the stuff. That was in the 60s I believe. Never heard much more about that material after that.

 

[Peter 315]

Weathering steel ...........Weathering steel - Wikipedia

 

[oosik]

Long ago I heard of a product - like what IT describes. Now they use some very specific formulated paints.

 

[Jstpssng]

^^^^
I had planned on working that into the thread, but you beat me to it. :laughing:

Weathering steel ...........Weathering steel - Wikipedia

I believe that's what I remembered. Thank you.

 

[Jim Nelson]

Out here in the land of fruits and nuts our local power company is starting to replace wooden poles with steel. The portion that is buried is coated in a black tar looking substance but the rest is bare steel that is rust covered. When they first started this I read an article that said they were coated with some kind of chemical that caused the rust covering and that it acted as a preservative. It looks like a good idea but I wish they would hurry up and get it done as we are looking at a potentially bad fire season right now.

 

[Alan W.]

Weathering steel ...........Weathering steel - Wikipedia

I remember reading about this years ago in one of the welding trade magazines. They were building a water tower out of it to save painting upkeep cost.

We have bridges and guardrails made from it around here.

 

[Doofy]

Our Post Office was sided with the rusty preservative finish. It was so buttugly and received so many complaints that it was finally painted. Looks much better now.

 

[oosik]

The electric co-op in our area put something like that on some major transmission poles. Must have been some form of experiment. It was only done on a dozen or so. Turned them from big galvanized structures to a chocolate brown color - more or less. Guess it didn't pass the "sniff test" - they never did any more of the poles.

Out going across the wheat country chocolate brown blends in no better than galvanized.

 

[RalphVa]

Be better to cover it with something like Rustoleum's Rust Reformer, which reacts any rust to iron sulfide. Rust actually catalyzes more rust.

Ralph