Powder Coating FAQs

Quick answers to common powder coating questions

Got questions about powder coating? You are not the only one. A lot of people want metal parts to look good and last, but are not sure how powder coating works, what it costs or whether it is better than paint.

This FAQ brings together the questions we get asked most, from “how do you powder coat metal?” through to “can you powder coat aluminium or stainless steel?” and “how long does powder coating last?”.

If you cannot see your question here or want advice on a specific job, just get in touch and we will give you a straight answer.

Powder coaters you can count on.

Frequently asked questions

How do you powder coat?

Short answer: prepare the metal properly, coat it evenly and cure it at the right temperature.

At The Powder Coaters we:

• Clean and pre treat every job so the powder can bond to bare, sound metal

• Adjust our prep for aluminium, mild steel, stainless and galvanised parts

• Hang parts so they are stable and can be coated all round

• Use controlled oven cycles so the whole part reaches curing temperature, not just the ends

• Inspect parts before and after coating so problems are caught before they leave the building

The spraying itself is only one piece of the puzzle. Most coating failures come from poor preparation or bad curing, not the powder brand.

How do you powder coat metal?

Powder coating metal follows the same principles as any powder coating, but surface preparation is even more important.

For metal parts we:

• Remove rust, scale and old coatings where needed

• Degrease thoroughly so oils and fingerprints do not interfere with adhesion

• Key or pre treat the surface so the powder can grip

• Check welds, corners and edges that can be prone to thin coverage

• Apply powder in an even pass and cure to the manufacturer’s specification

Different metals behave differently. Aluminium, mild steel and galvanised steel all need tailored preparation, which is why a “one process fits all” approach often causes problems.

Can you powder coat aluminium?

Yes. Aluminium can be powder coated very successfully and is one of the most common materials we work with.

The key is dealing with the natural oxide layer and any oils or dirt on the surface before coating. We:

• Clean and degrease to remove cutting fluids and contaminants

• Pre treat the aluminium to tackle oxidation and improve adhesion

• Dry thoroughly so no moisture is trapped under the coating

• Apply and cure the powder to suit the section size and profile

Done properly, powder coated aluminium gives a clean, modern finish that lasts well on frames, extrusions, gates, components and more.

Can you powder coat stainless steel?

Yes, stainless steel can be powder coated, but it needs careful preparation because the surface is naturally smooth and corrosion resistant.

To get good adhesion we usually need to:

• Clean and degrease to remove oils and polishing residues

• Lightly key or blast the surface to give the powder something to grip

• Use suitable primers or pre treatments where required

If stainless parts are going into a harsh environment, we will talk through what the part is doing and how it is used before recommending a coating system.

Can you powder coat galvanised steel?

Yes, galvanised steel can be powder coated and the two together make a very durable system.

However, galvanising leaves a zinc layer that can cause problems if you do not prepare it properly. We:

• Lightly sweep blast or mechanically key the surface to improve adhesion

• Remove any white rust, dirt or contamination from storage and transport

• Control the oven cycle to reduce the risk of pinholes and gas coming out of the zinc layer

When done correctly, powder coated galvanised steel is ideal for gates, railings, handrails and outdoor fabrications.

Can you powder coat plastic?

In most cases, no. Standard powder coating needs high curing temperatures that most plastics cannot withstand. They soften, warp or melt long before the powder cures.

There are some specialist low temperature powders and high temperature plastics where it can work, but this is not typical day to day work and is not what our line is set up for.

If you need a coloured or protective finish on plastic, it is usually better to look at liquid paints or coatings designed specifically for plastics.

How much does powder coating cost?

The cost of powder coating depends on a few main factors:

• Size and shape of the part

• Quantity (one off or batch work)

• Type of metal and how much preparation is needed

• Colour and finish, including any special textures or effects

Simple, small parts in a stock colour are cheaper per item than large, complex fabrications in special finishes.

We price jobs once we know what you have, how many there are and what finish you want. That way you get a clear figure and realistic lead time rather than a guessed price that changes later.

How long does powder coating last?

There is no single answer because it depends on:

• The metal and how well it was prepared

• The environment (indoor, outdoor, coastal, industrial, sheltered)

• How much wear, impact or abrasion the part sees

With proper preparation and a suitable powder, a powder coated finish on metal can last many years in normal conditions without needing attention. In harsher environments, there are specific coating systems and maintenance routines that can extend life further.

We always ask where the part will be used before we recommend a coating approach.

Is powder coating better than paint?

For many metal parts, yes. Powder coating is often better than basic liquid paint because:

• It forms a thicker, more even layer in one process

• Once cured, it gives a hard, impact resistant finish

• It resists chips and scratches better in normal use

• It offers a wide choice of colours, gloss levels and textures

Paint still has its place for on site work, quick touch ups and parts that cannot go in an oven. But if you are looking at gates, railings, frames, extrusions or fabrications that need to look good and last, powder coating is usually the stronger long term choice.

How do you check quality?

We build checks into every stage rather than only looking at the part at the end.

That includes:

• Visual and tactile checks during cleaning and prep to spot rust, contamination or problem areas

• Checks on hanging and jigging so parts are stable and can be coated evenly

• Monitoring oven temperature and dwell times against the powder manufacturer’s guidance

• Final inspection once parts are cool, checking coverage, edges, corners, gloss and general appearance

If something is not right, it does not go out. We would rather fix an issue in the shop than have you find it when the part is already installed.

What metals can you coat?

We mainly coat:

• Aluminium extrusions, frames and components

• Mild steel fabrications

• Galvanised steel gates, rails and structures

• Some stainless steel parts

Each metal needs slightly different preparation and handling. Aluminium, mild steel and galvanised steel are what our process is optimised for.

If you have a more unusual metal or casting, we are happy to look at it and give honest feedback on whether it is suitable for powder coating and what results you can expect.

Do you pre treat the parts?

Yes. Proper pre treatment is at the heart of what we do. Skipping it is the fastest way to get coatings that peel, chip or rust early.

Every job goes through a prep process that can include:

• Degreasing to remove oils, dirt and fingerprints

• Mechanical or chemical preparation to tackle rust, scale or oxidation

• Drying so there is no moisture left on the part before coating

For aluminium and galvanised steel, we use specific methods tailored to those materials so the powder can bond to a clean, sound surface.

What finishes are available?

We offer a wide range of powder coatings, including:

• Matt, satin and gloss finishes

• Smooth and fine texture options

• Standard stocked RAL colours

• Selected special and metallic effect powders, subject to availability

If you need to match a brand colour or an existing item, we will work with you to find the closest available powder. Some special finishes may have longer lead times or minimum order quantities, which we will explain up front.

How tough is the finish?

Powder coated metal is designed to be tough. Once cured, the coating forms a hard, continuous skin that resists:

• Everyday knocks and scrapes

• General wear from handling and use

• Normal weather and UV exposure

It is not indestructible, and very sharp impacts or abuse can still damage it, but for most gates, railings, frames, brackets and general fabrications, powder coating gives a much more durable finish than basic sprayed paint.

Can you handle high volumes?

Yes. Our set up is built to handle both one off jobs and ongoing batch work.

For higher volumes we:

• Agree clear specifications and colours up front

• Set up consistent jigs and hanging methods so parts run the same way each time

• Plan oven loads so throughput is steady without rushing the cure

• Keep communication open on lead times, collections and deliveries

If you have regular production work, we can look at repeat schedules and stock colours so your parts move smoothly through our line.

Made to last. Backed by experience.

What we’re known for

Quick turnaround

Fast, friendly and efficient service without cutting corners.

High quality finish

Reliable service

Every part is pre-treated and inspected before coating.

We stick to our word and keep you updated along the way.

Why use our powder coating service

You are not getting generic advice copied off a datasheet. You are talking to people who coat metal every day.

When you ask us for help, you get:

• Honest views on whether powder coating is right for your job

• Clear explanations of what will happen to your parts

• Straight answers on cost, lead times and realistic results

• Guidance tailored to aluminium, mild steel and galvanised steel

If powder coat is not the best option, we will say so. If it is, we will explain the best way to set the job up.

Explore The Powder Coaters

Powder Coating Services

Powder coating services for aluminium and metal parts, with proper surface preparation, consistent finishes and clear lead times from our family run site in Iver.

Aluminium Powder Coating

Metal Powder Coating

Aluminium powder coating for extrusions, frames and components, with full pre-treatment and capacity up to 7 m for a tough, even, long lasting finish.

Metal powder coating for steel and galvanised steel, with proper surface preparation and durable finishes that protect against rust, chips and everyday wear.

Read through the guides and still not sure what to do next?

Tell us about your parts and how they will be used, and we will give you straightforward advice and a clear quote.