Over-Painting steel tubing

[RickH]

I have a an adjustable steel hand rail ….
This is 2” steel tubes which have a Matt black finish ….I think it’s paint, as no flaking which happens with powder coat. Photo of new item attached.

It was supposed to be for outside use for Hot Tubs …. In less than 9 months it’s rusting significantly, and it’s under a hard roof ….. presumably not fairing well to coastal salt air.

I need to overpaint it, can abrade to give a key, chemical clean ….
Anybody recommend a pain finish to apply?
Needs to be in spray can …. To get even smooth cover.

Should I use some primer, or barrier coat.

Thought of : https://www.halfords.com/motoring/p...-paints/halfords-matt-black-500ml-258771.html

Another option might be Hammerite smooth spray … would work on bare metal parts & and rust

Hammerite Direct To Rust Smooth Aerosol Spray Paint

A smooth metal paint that can be applied metal including railings, garden furniture and gates. Available in a range of colours with fast despatch.

nextdaypaint.co.uk

But happy to know if something better.

 

[JohnD]

I'm not keen on Hammerite. Rust can grow beneath the paint film and if is very difficult to patch, repaint or strip. It is advertised to amateurs as if it was a magic potion that does not need preparation.

If the steel has no zinc coating, I'd sand it lightly, apply Kurust on any rust patches, then use a ferrous preservative primer (I'm currently using a grey Dulux product, it is very heavy in the can and expensive. Red Oxide is a cheaper alternative.) followed by a conventional gloss oil paint system. Leave no exposed bare metal. I don't think Calcium Plumbate primer is still available. IME zinc primers go on thickly and dry very soft

If outdoors exposed to sun, avoid black topcoat because it absorbs heat from the sun's rays, causing the metal substrate to expand, then contract when it cools, which promotes cracking of paint films unless they are very thin. A protective paint system is relatively thick.

BTW I am in a coastal location and mostly use stainless steel outside.

Cheap Chinese stainless without nickel content is poor quality, soft, weak and with poor tarnish and corrosion resistance, but better than BZP mild steel. You can get proper graded stainless at higher cost, the good stuff seems to come from Germany.

 

[RickH]

I don’t think it’s zinc coated, due to rust in places.
It is outdoors and it is black, appreciate your comment, but don’t want to change the colour.
Will ‘Ferrous preservative primer’ work on top of paint. ?

I’d agree that SS in 316 grade be much better, but could not find one in SS.


Agree that standard Hammerite is not as good as thought. …the thin ‘pits’ does not perform well in salt air.
I have not used the spray smooth hammerite - hence was only suggestion.

 

[JohnD]

Will ‘Ferrous preservative primer’ work on top of paint. ?

I don't know. Zinc-type coatings seem to protect small scratches, but we have already seen that the original black paint is not up to much, so maybe better to abrade it off and start afresh, wet and try carborundum paper cuts through thin coatings easily.

 

[RickH]

I don't know. Zinc-type coatings seem to protect small scratches, but we have already seen that the original black paint is not up to much, so maybe better to abrade it off and start afresh, wet and try carborundum paper cuts through thin coatings easily.

Removing all the paint is not an option, far too much work to do that.

 

[Deleted member 265726]

I re-did all my cast iron pipework at the front of the house several years ago. I am just inland from the coast by about a mile, so not too badly affected. I used a primer and a top coat. I used two different types of primers independently of each other, they were Hammerite Rust Beater and Fortress Primer because I already had them and so just used them up. They are super thick so I applied thin coats using a roller on the front of the pipes and a paintbrush at the backs. I top coated with Leyland Direct to Metal paint. I've only had to touch up a bit since around the collars.

I tried the same method of primer and top coat in spray form on rusting ironmongery on my shed and it was a shambles. All of it rusted within a year. I've wasted a lot of time and money on this and so I bought stainless steel ironmongery instead.

I should add, this was all done after removing all the old paint and rust back down to clean bare metal.

 

[RickH]

I re-did all my cast iron pipework at the front of the house several years ago. I am just inland from the coast by about a mile, so not too badly affected. I used a primer and a top coat. I used two different types of primers independently of each other, they were Hammerite Rust Beater and Fortress Primer because I already had them and so just used them up. They are super thick so I applied thin coats using a roller on the front of the pipes and a paintbrush at the backs. I top coated with Leyland Direct to Metal paint. I've only had to touch up a bit since around the collars.

I tried the same method of primer and top coat in spray form on rusting ironmongery on my shed and it was a shambles. All of it rusted within a year. I've wasted a lot of time and money on this and so I bought stainless steel ironmongery instead.

I should add, this was all done after removing all the old paint and rust back down to clean bare metal.

It's annoying that product is less than a year old, and is intended for outdoor use and the paint finish not up to it. As it's only failed in places I don't want to strip the whole lot back to back metal.

 

[Deleted member 265726]

It's annoying that product is less than a year old, and is intended for outdoor use and the paint finish not up to it. As it's only failed in places I don't want to strip the whole lot back to back metal.

I suspect the same powder coating you have on the hand rail is the same coating I had on my ironmongery. It is carp. There aren't any shortcuts in DIY if you want to do it properly but it is up to you. Perhaps look at an aluminium hand rail instead if you have the funds and they make them.

 

[RickH]

I suspect the same powder coating you have on the hand rail is the same coating I had on my ironmongery. It is carp. There aren't any shortcuts in DIY if you want to do it properly but it is up to you. Perhaps look at an aluminium hand rail instead if you have the funds and they make them.

This is under a year old …. I bought it after ‘rave reviews’ …it’s solid construction but poor finish.
Can’t afford to lay out on replacement, hence wanting to ‘touch up the paint’.
The top section slides into lower section with little clearance, plus it rotates. So no option to use a thick primer/paint.

 

[Deleted member 265726]

This is under a year old …. I bought it after ‘rave reviews’ …it’s solid construction but poor finish.
Can’t afford to lay out on replacement, hence wanting to ‘touch up the paint’.
The top section slides into lower section with little clearance, plus it rotates. So no option to use a thick primer/paint.

So was my ironmongery. In that case, finely sand down but do make sure you get all that rust out. Anything left will start the entire corrosive cycle off again. Then just do what you suggested which is to spray paint it. If space is that tight, do you have enough room for a primer coat? I wouldn't expect it to endure mind, but it will buy you some time to look out for a good deal on a stainless steel or aluminium replacement. As JohnD said, the stuff coming out of China is below standard. Stick to marine grade stainless steel stuff for your location

 

[RickH]

I'll remove & treat rust with kurust.

 

[Deleted member 265726]

A fine wire brush would be a good shout.

 

[RickH]

A fine wire brush would be a good shout.

Plenty of them ?

 

[Deleted member 265726]

Plenty of them ?

You shouldn't need more than one for this job. How corroded is the hand rail? I thought you just had a bit of rust rather deep extensive corrosion at this point?

Can you put some pics up of the rust please?

 

[RickH]

3 pics of worst parts attached.
Less than 5% of the whole.