Bitumen paint

[Simon]

Has anyone tried this on metal outdoors? I have some iron railings I want to paint and the Hammerite paint I use keeps lifting with rust every 12 months so I thought I might give this a go. If anyone has tried it what is the finish like?

Thanks.

[Rob graham]

This is fine for iron railings but you have to give up the idea that you can keep rust at bay with anything short of galvanising, or keeping them oiled. Although there are many products which allegedly cure rust I doubt if there is anyone other than the manufacturers who finds that they work.

Bitumen paint finish is quite reasonably glossy, although not as glossy as real gloss paint. I'm sure you'll find it OK.

Rob Graham

[diypaint]

The first question is, why is the hammerite is failing? Rust loves a supply of air, water & metal(!). Assuming you're completely cleaning down the surface first, then you should prevent rust with hammerite - providing that the surface is completely covered. This includes corners and edges, which tend to be weak points which can be tricky to cover with paint. You may need to put down multiple coats to ensure complete cover. Also, if you dealing with a tricky surface, try applying Hammerite No1 Rust Beater before applying the topcoat.

Bitument paint may work, as it provides a good barier to water. However, you could end up with the same issues as you have with the hammerite unless you prepare the surface properly and coat the metal completely. You may also need to apply a zinc-phosphate primer before application of the bitumen paint. The zinc in the primer works in the same way as galvanising. It can prevent rust creeping along the surface, should rust get started in a particular point due to a film defect.

good luck

[Cicero]

=================================== My experience of bitumen paint ('Bitumastic') is that it goes very dull after a short time. Protection is good if used on dry metal.

Cic.

[Simon]

Thanks for that guys,

The reason the rust keeps coming through is that the cross beams that the railings actually go through, both top and bottom, holds the rain water after a downpour, the rain rests on them in balls of water, the railings themselves are fine. I need something that is completely waterproof to try and stop the rain water penetrating the paint. I am at the moment getting the cross beams to bare metal where they have bubbled up and applying Red Oxide paint (2 coats) before giving the bitumen paint a go. in hind sight I agree that Galvanising would probably be best. What do you think of Johnsons water seal or something like Scotch Guard after I have painted them? Can I paint over this stuff at a later date if I need to? Questions, Questions, Questions lol.

Thanks again.

[James]

OOps! Bitumen does not adhere well to red oxide.

I used to have a narrow boat whose hull was painted with bitumen based paint. During a dry-dock I decided to paint the areas around the waterline with red oxide and found the bitumen lasted about as long as it took to apply. I was told this before I applied the oxide and decided I knew better, to my cost!

Bitumen is initially bright in finish but soon settles off to a dull grey black sheen.

I did paint one boat with black gloss on top of the bitumen, which looked quite smart between dry-docks, the two paints seemed to get along quite well together.

The cheapest source I found for "bitcho" was Wilko, the Midlands hardware type store. The Wilko chain may be elsewhere in the country also.

[Simon]

Gulp,

Thanks for that James, I was going to buy some Bitumen pain tomorrows from Wilko's but as I have already painted the fending with Red Oxide I'll take your word for it and not put the Bitumen on top if it doesn't stick to it and I'll go back to the Hammerite.

Cheers.