Metal finishing Q&As since 1989

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Want to Hot Dip a Radio Tower

I am an amateur radio operator and have a Rohn tower which has fairly heavy rust on the cross braces, but the tower legs are relatively rust free. I am thinking about getting it hot dipped galvanized. While the cross pieces have pretty heavy rust, they are structurally sound. Will the pickling process be able to remove this rust?

Ken Florence
hobbyist - Morgantown, PA, USA
December 16, 2009

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December 17, 2009

Hi, Ken. The pickling should easily remove any rust, although it can't repair any pitting damage. Are you intending to disassemble or to dip large sections?

Regards,

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

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Most jobbing galvanizers commonly get steel fabrications that have served many years (decades) of service and come back for a new coating.
The pickling process will remove very thick rust, but its a time factor, so can be uneconomic to use only pickle acid for this. If the rust is thick enough to pick flakes off with your fingernail, then probably shotblasting is called for.
Most galvanizers want things in their pickle tanks for under a couple of hours. Very thick rust might take a day.

Geoff Crowley
Crithwood Ltd.
Westfield, Scotland, UK

December 18, 2009

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December 21, 2009

Thanks for the responses. The tower will be disassembled into 8 foot sections. It seems like the company that I want to use will not have any problem handling the size of the towers.

I am not very worried about the pitting since this thing is not for looks. There is not any flaking of the rust, it is just fairly heavy. Best I can say is that it feels like sandpaper when you run your finger over it. But there is not any loose rust.

Thanks for the help!

Ken Florence
- Morgantown, Pennsylvania