any old iron

[John]

Screwfix do an excellent rust converter which we used on cast iron gutter after using a wire brush on a grinder. Then we put red oxide on, then two coats of the topcoat. I highly recommend the rust converter. A little goes a long way. Always pour some into a seperate container to use to avoid getting rust in the pot.

[stuart]

I have an old exterior spiral staircase in pretty rough condition. I have given it a quick going over with a grinder and removed all the flaking rust, but do I need to remove all the rust completely before painting with red oxide undercoat? Or would anyone recomend a rust converter instead of red oxide? I intend to use a good water based top coat on it. Thanks for any help Stuart