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The best paint for metal surfaces

On metal, a water-based multi-surface finish — Eggshell, Satin or Gloss — over one coat of Multi-Surface Primer wherever the metal is bare; on sound, already-painted metal, a wash and a sand are enough before the two coats. Indoors as outdoors: Mylands multi-surface finishes are formulated for both. Rust is treated before, never after. And black is not compulsory: a deep green gate, a midnight-blue banister, a coral garden chair last just as well.

Page updated September 2026 · by the Mylands France colour team

Wrought-iron garden railings painted a deep green-black in a gloss finish, in front of a pale rendered wall and a hedge, morning light — Market Green No.38 in Multi-Surface Gloss: the green-black of London railings

Understanding

Metal asks for one thing only: a key

Wood drinks paint, plaster absorbs it; metal does neither. Smooth, non-porous, sometimes greasy, it lets a paint that has nothing to hold on to slide off — hence the radiators that flake and the gates that peel. Everything happens at the primer and the preparation: bare metal, degreased and sanded, takes Multi-Surface Primer, which bridges between the steel or cast iron and the finish; sound, already-painted metal only needs washing and dulling.

The second rule is rust. It keeps working under the paint if you seal it in: brush it, sand down to sound metal, convert it if it is extensive, and only then prime. Mylands finishes are water-based; on bare steel they always go over primer, never directly, to avoid the flash rust that water can cause.

Choosing

Which finish for which metal

The metal	Finish	Primer	Note
Cast-iron or steel radiator	Eggshell (blended into the wall) or Satin	Multi-Surface Primer on bare metal	Paint cold, 48 h before switching on — see How to paint a radiator
Iron bed, chair, table, indoors	Eggshell or Satin	Multi-Surface Primer on bare metal	Thin coats, into the tubes and scrolls
Banister, handrail, balustrade	Satin or Gloss	Multi-Surface Primer on bare metal	Hands polish a matt: go up in sheen
Gate, railings, outdoor balustrade	Gloss (the toughest) or Satin	Multi-Surface Primer, two coats on treated rust spots	Inspection every spring, chips touched up at once
Iron or steel garden furniture	Satin or Gloss	Multi-Surface Primer	Bring in or cover for winter — see How to paint garden furniture
Aluminium, galvanised, stainless	Satin or Gloss	Special non-ferrous metal primer, then the finish	Multi-Surface Primer is for steel and cast iron; check the technical sheet
Powder-coated metal (aluminium window, modern gate)	Satin	Careful dulling + suitable primer	Test on a hidden face: the key depends on the coating

The three finishes exist in every colour, water-based, low in VOCs, recoatable after 3 to 4 hours, cured in two to four weeks. See Gloss, Satin, Eggshell.

The method

Preparing and painting metal in six steps

01

Degrease

Sugar soap or degreaser, sponge, rinse, dry completely. Metal keeps an invisible film of grease — machining oil, hands, cooking — that makes any paint bead. On a gate, a hose down then a sponge.
02

Remove the rust, down to sound metal

Wire brush, then 120-grit abrasive, or a disc on a drill for a gate. Where rust has pitted deep, a rust converter stabilises what cannot be removed. Scrape off any old flaking paint too. Dust off thoroughly: rust dust under the paint is rust starting again.
03

Dull the sound painted metal

A sand with 180 over all the old paint that holds, to break the sheen and give a key. Damp cloth, dry.
04

Prime the bare metal, without waiting

Bare steel rusts within hours in damp air: Multi-Surface Primer goes on the same day as the sanding, in a thin coat, by brush, wherever metal shows — and over the whole gate or piece if it is new. Recoatable after 3 to 4 hours. Two coats on treated rust spots.
05

Two thin coats of finish

Brush for scrolls, tubes and bars; small foam roller for flat sheet, followed by a lay-off with the brush. Thin coats: on metal a thick coat runs and stays soft for days. Second coat after 3 to 4 hours. Outside, in dry weather, out of direct sun, above 10 °C.
06

Let it cure before use

Touch-dry in 2 to 3 hours, handleable the next day, hard in two to four weeks. A gate is closed gently in that time; a garden chair waits a week before being sat on; a radiator waits 48 hours before being switched on.

Close-up of an iron railing bar: one part brushed to grey metal, one part primed, one part painted glossy green-black, a wire brush beside it — The three states: sound metal, primer, finish — in that order, with no wait between the first two

The colours

Six metals, six colours

Metal is traditionally black or white. It has no reason to be. Six pairings, with what surrounds them.

The green-black railings

The green so dark it passes for black on London railings, in Gloss, in front of pale render or brick.

Railings · Market Green No.38

The midnight-blue banister

An iron stair rail in a deep blue in Satin, grey-white walls: the rising line becomes the hall's drawing.

Banister · Blueprint No.50 Walls · St Clement No.11

The grey-green iron bed

An old iron bed in a soft grey-green in Eggshell, powder-pink walls: the metal stops being cold.

Bed · Long Acre No.102 Walls · Threadneedle No.262

The coral garden chairs

Four iron chairs in a soft coral in Satin, on a stone terrace, against planting: the colour of summers.

Chairs · Coral Orange No.277

The slate-grey gate

A dark grey-blue in Gloss on a modern gate, with shutters in a lighter grey of the same family.

Gate · Bond Street No.219 Shutters · Long Acre No.102

The blended radiator

The radiator in the exact wall shade, in Eggshell: the plainest object disappears.

Wall & radiator · Hawksmoor No.112

To avoid

What makes metal peel

Painting over rust. It carries on underneath and lifts the paint in brown blisters.
Leaving metal bare overnight before priming. Flash rust sets in within hours of damp air.
Skipping the degreasing. The paint beads and comes off under a fingernail.
Wall emulsion on metal. It is formulated for neither the key nor the heat.
One thick coat to save time. It runs on the bars and stays soft for weeks.

Entrance to a house: glossy green-black railings and gate, gravel path, pale rendered façade, front door in the same green-black — Railings, gate and front door in the same Market Green No.38

Frequently asked questions

Your questions, our answers

Can metal be painted directly, without primer?

On already-painted, sound, washed and dulled metal, yes: two coats of finish. On bare metal, no: the primer is what holds the finish, and what protects the steel from rust under a water-based paint.

How do I treat a very rusty gate?

Mechanical brushing, sanding to sound metal where possible, rust converter on deep pitting, two coats of Multi-Surface Primer, two coats of Gloss. If the metal is holed, it is a blacksmith's repair before it is a paint job.

Does a water-based paint last outside on metal?

Yes: Mylands multi-surface finishes are formulated for exterior use, over primer. Gloss is the most resistant to rain and UV. An inspection every spring and the immediate touch-up of a chip keep a gate going for years.

Which sheen for a banister or handrail?

Satin or Gloss: hands polish a matt within months and leave greasy marks. The higher the sheen, the better the surface washes.

And the kitchen's metal — extractor hood, oven, kitchen radiator?

A hood or a metal frame, yes, with the same method and a double degrease. The oven, the hob and anything that gets very hot, no: those need specific high-temperature paints, outside our range.