It was cool but bright the day before ConExpo opened in Las Vegas, and there, gleaming in the sun like a big piece of pewter, was a side-dump trailer whose steel underframe was completely galvanized.

So were its suspension hangers, air-bag caps, push block and many other pieces. Hmm, I thought. Here's something to circle back on.

Galvanizing - dipping the steel in molten zinc - seems to be a cost-effective way to fight corrosion, a major problem for truckers since road departments began using aggressive de-icing chemicals. In recent years I've seen galvanized parts on vans from several builders, but couldn't recall seeing them on construction-oriented trailers.

What was news to me is nothing new to people at Manac, which built this dumper at a plant in Missouri. Keith Limback, the Canadian company's sales manager in the U.S., said they began using galvanized parts on vans about 16 years ago.

Several rear pieces on this side-dump trailer are standard with it, while the undercarriage galvanizing is an $800 option. That's all? I asked. It is pretty economical for the protection you get, Limback agreed.

"With a standard steel trailer, you've got to figure on completely sand-blasting and repainting it at least once in its lifetime, and that will cost a lot more than $800," he said.

Not everyone can offer a galvanized main frame, trailer makers have said in the past. The difficulty is finding a supplier with a hot-dip tank big enough to take the long frame members. Manac and others know of them, so can offer this method of protection against corrosion. And it almost glows in the sun.