Sorting rusty box steel.

WIAWSNB

Hi.
Box section steel sections, with extensive, but surface, rust.
I'll be wire brushing to get rid of all loose stuff, but what then? What are the latest solutions?
Used to be things like rust 'converter', which supposedly turned rust into an inert and hard compound, ready for painting over.
Any good? Any recommendations? And best paint to use on top?
Or, go traditional, and 'red lead' the rusty finish, and then overpaint?
Or, specialist products like POR 15?
Ta. 

grumpy_codger

Whatever you paint it with later, get rid of the rust first, don't paint over it. Yes wire brushing, sanding then rust converter for the remaining bits.

fwor

It depends on what the box section is (e.g. is it a structural component such as a box lintel), what environment it is in (e.g. outside, exposed to the elements, or inside but in a permanently damp environment) and whether the finish will be seen or covered over.

If it's in a dry environment and not in view then just wire-brushing loose rust off and painting over with a product such as smooth Hammerite should be perfectly OK. It's not a durable finish in my experience, but if it's not being touched it should be fine. More durable options would include one of the two-part epoxy paints (preferably not one that has to come from the US). I've used one of those before and the finish is incredibly durable (but hard to make look really good if applied with a brush).

bjorn_toby_wilde

Kurust seems pretty good. I think it’s a Hammerite product.

WIAWSNB

Grumpy, yes I'll be wire brushing all loose stuff off first.
Do 'rust converters' work as well as they say?
Fwor - soz, yes, outside and wet conditions. Kit car chassis sections.
Not particularly visible, so not a major consideration, but would still like it decent. It doesn't have to be smooth, tho', so I'm happy to say 'stipple' for a textured finish. 
I agree - I'm not keen on Hammerite either as I find it too susceptible to chipping, and also annoying having an unusual solvent - cellulose?
Two-part epoxy sounds good, but complex!
No modern miracle products? 
Cheers.