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.

WIAWSNB

bjorn_toby_wilde said:

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

Is that a coating or a converter? Ta.

fwor

WIAWSNB said:

Kit car chassis sections.

Ah, right. As this is in the "In my home" section I was assuming a window lintel or some similar structural building component!

If it's for a car, I would recommend one of the modern epoxy-mastic finishes. The one that I used on my 60's Jensen is called "Rustbuster Armaguard", and I reckon it's good (but expensive). It's durable for road conditions because it has high enough viscosity to create a thick coating in one or two coats. The downside (other than cost) is that it's difficult to eliminate brush marks, so it's not really suitable for places that are in normal view (I used it exclusively on the underside of the Jensen), unless you have facilities to spray a 2-part finish.

As with Hammerite, it uses an unusual thinners (not cellulose thinners, which won't work with Hammerite either) but a standard pack comes with epoxy mastic, hardener and thinners.

WIAWSNB

fwor said:

WIAWSNB said:

Kit car chassis sections.

Ah, right. As this is in the "In my home" section I was assuming a window lintel or some similar structural building component!

If it's for a car, I would recommend one of the modern epoxy-mastic finishes. The one that I used on my 60's Jensen is called "Rustbuster Armaguard", and I reckon it's good (but expensive). It's durable for road conditions because it has high enough viscosity to create a thick coating in one or two coats. The downside (other than cost) is that it's difficult to eliminate brush marks, so it's not really suitable for places that are in normal view (I used it exclusively on the underside of the Jensen), unless you have facilities to spray a 2-part finish.

As with Hammerite, it uses an unusual thinners (not cellulose thinners, which won't work with Hammerite either) but a standard pack comes with epoxy mastic, hardener and thinners.

Thanks - that's certainly good stuff, but OTT for me, I think - I really don't like the idea of 2-part, for simple practical reasons; wrecked brushes, pots, having to use it all up, etc. 

Now, if I had a Jensen, then...

fwor

WIAWSNB said:

Thanks - that's certainly good stuff, but OTT for me, I think - I really don't like the idea of 2-part, for simple practical reasons; wrecked brushes, pots, having to use it all up, etc. 

Now, if I had a Jensen, then...

I'll be honest - I thought the same. Complicated mixing, short time of use before it hardens, short shelf life? But... in my experience, none of those were true. It's just equal parts of mastic and hardener (the colour is actually in the hardener as supplied) and a variable amount of thinner depending on how thick you want the mix to end up. I just bought some plastic disposable cups to do the mixing in and some cheap Chinese plastic-bristle brushes so that I could throw them away - I think they were 5 for a £. The only thing I had to do with the brushes was to cut them shorter to give a more rigid brushing action.

bjorn_toby_wilde

WIAWSNB said:

bjorn_toby_wilde said:

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

Is that a coating or a converter? Ta.

It’s a converter, but I’ve never used it on anything like a chassis. Just garden gates, etc.

Sounds like you have an interesting project going there.

WIAWSNB

bjorn_toby_wilde said:

WIAWSNB said:

bjorn_toby_wilde said:

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

Is that a coating or a converter? Ta.

It’s a converter, but I’ve never used it on anything like a chassis. Just garden gates, etc.

Sounds like you have an interesting project going there.

It's a Cortina. Dressed up as a Jeep CJ-7 - Eagle RV :-)