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High Temp Corrosion-Resistant Non-Paint Finish for Mild Steel

I am welding a brewing stand from 2 inch by 2 inch square 11 gauge mild steel. It will sit outdoors on my partially covered porch, somewhat protected from sun and rain. The top frame pieces will be fairly close to the flame from the natural gas burners, but not directly over the fire. Still, they will get very hot during brewing.

I think the best option to prevent rust is to use a high-temperature primer and paint on the area near the burners, and a regular primer and paint on the rest of it. But I'd like to know what other non-paint finish options might work in this application, especially any that might preserve some of the natural metal color or look.

For example, would a mixture of boiled boiled linseed oil ⇦ this on eBay or Amazon [affil links] , turpentine ⇦ this on eBay or Amazon [affil links] , and japan dryer, applied cold then scorched with a propane weed burner provide good corrosion resistance to the mild steel brew stand on my partially protected porch?

How about cold zinc treatment (e.g., from a spray can)? Can it take high heat in the area near the gas burners?

Are there any plating techniques that would provide the necessary protection and that could be done without immersion? The stand is 52 inches long, 16 wide, and 34 inches tall, too big to immerse.

Stephen Cook
hobbyist - Dallas, Texas
2007

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You get it galvanized. Would be good for about 400 degrees C, and take all the knocks you give it. Its not to big for that process.
You don't actually state what temp it has to withstand?

Geoff Crowley
Crithwood Ltd.
Westfield, Scotland, UK

2007

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Thank you Geoff,

The top of the stand will have three eight inch natural gas burners in it, 150,000 BTUs each, but I honestly don't know how hot the metal will get. The burners might be fired for up to 90 minutes at a time. The metal will not be directly in the flame. More like an inch or two away and to the side.

I want it to look attractive. I think powdercoat would melt. I'm not sure what galvanized zinc would look like. Natural gas burns at over 3500 °F (~1950 °C), but like I said, no part of the metal frame will be directly in the flame. I expect it could get hotter than 400 °C though.

Stephen Cook
- Dallas, Texas
2007

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June 22, 2008

Hi, Stephen. The ideal solution would be porcelain enamel (which is more like fused glass powder than like paint or powder coating), but it's not something that you can do yourself.

If you want to do it yourself, high temperature spray paint might be best, and I'd be very surprised if it couldn't take the heat.

The hottest point of a gas flame may well be 3500 F (I didn't check), but I don't think it can make a heated object approach that temperature. The melting point of iron is hundreds of degrees lower than that. Good luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey