How to prepare hot rolled sheet for priming & painting?

Q. Hello everyone, I found a lot of useful information on this site; however I've not been able to find what exactly I'm looking for.

I have installed Hot Rolled sheets for my roofing. These have not been sand blasted before installation. The sheets have an overlap of 3 inches on each other. They have been welded to each other at intervals of 4 inches.

My query is what protective paint and primer should I use for the protecting them from rust. Secondly, is there any solution that I can use to clean them of all the oil and grease (the blackish dirt on them) before painting. My main issue is surface preparation as I have not sand blasted them.

Please guide me with this, as I have been looking everywhere, but haven't had any luck yet.

Do look at the photographs attached to get an idea of the present condition of the sheets.



Thanks in advance

A. Use a solution of trisodium phosphate ⇦ on eBay or Amazon [affil link] ; scrub and rinse well. If you can get hold of some zinc phosphate solution, icing on the cake; spray on, let dry, prime and paint.

Ronald Zeeman
Coil Coating - Brampton, Ontario, Canada
March 19, 2012

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April 7, 2012

A. Hello Shabab,

If it's not too late, still use Galvanized Steel Sheets, or precoated steels sheets instead of HR Steel; you won't have to redo the roof in 5 years.

Khozem Vahaanwala
Saify Ind

Bengaluru, Karnataka, India