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Architect questions on Mild Steel Countertop Finishing 

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I am in the process of designing/specifying a custom home for which the countertops are desired to be mild steel with an "oil-rubbed"- or "blued"-type finish. The countertops are to be welded flush and continuous on site, so the pieces are going to be much too large and unwieldy to be subjected to any sort of immersive finishing process. I have been doing some research, and have discovered that the two main options that appear to be available are:

1) torch heating and rubbing the steel with mineral oil to achieve a "blued"-type finish, and,

2) Chemical liquid cold-blueing

My questions are as follows:

A) What are the durability issues related to these finishes?

B) What are the maintenance issues related to these finishes?

C) What (if any) are the toxicity issues related to using these finishes on a food preparation surface?

Any help would be appreciated.

Thanks in advance.

Gregory W. [last name deleted for privacy by Editor]
architect - Seattle, Washington

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The basic problem, either way, is that steel rusts--almost instantly. When you look at a blued rifle barrel, it is only the oil that keeps it from rusting. Strip the oil and it will flash rust in 15 minutes. So the only way to keep the countertop from rusting is to clear coat it or keep it covered with a thin coat of some kind of wax or oil.

The steel itself poses no hazard; people use rusty frying pans and knives all the time. But what kind of oil, other than food-grade, would be safe?

I think this project justifies a mock-up where you lube a test plate with olive oil^^{mineral oil} and see what happens after you wash it with detergent, cut tomatoes on it, , etc., before committing to building it. An alternative might be color oxided stainless steel.

Ted Mooney, P.E. finishing.com Brick, New Jersey

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March 2, 2010 I am planning on doing the same in my home. I have some experience with steel. Mineral oil is non toxic often recommended to treat cutting boards, butcher block tables, etc. => I would not use olive oil... question if will eventually go rancid. I plan on bluing like you suggested, heat and oil and then coating it with beeswax, => hand rubbing it or a polisher will do too. It will give a high sheen finish but it will maintain the anti-rust aspect. Yes it will require maintenance but not very often I believe. Good luck! Sean McGrath - Belgrade, Montana ANSWER or FOLLOW UP POST an unrelated QUESTION HOT Topics

Beeswax