Metal Paints

Dealing with Rust

Rust can be a costly and sometimes catastrophic issue that affects metal surfaces, compromising both their strength and appearance. Understanding rust and how to manage it is crucial for maintaining the integrity and lifespan of metal structures. 

Rust occurs when iron reacts with oxygen and moisture, leading to the formation of iron oxide. This process can be accelerated by environmental factors such as humidity, salt exposure, surface damage (wear and tear, impact defects, abrasion from cleaning equipment, etc.) and temperature fluctuations. Properly addressing rust involves identifying early signs, such as discoloration and pitting, and taking preventive measures to protect the metal.

Your 3-step guide to understanding, diagnosing and getting rid of rust is:

• What is Rust?: Rust, or iron oxide, is often a reddish-brown colour which flakes off easily, exposing the underlying metal to the elements and furthering corrosion.
• Spotting Rust: Look for discolouration, pitting, and flaky surfaces. Early rust appears as small spots or streaks, while advanced rust can cause significant structural damage.
• Preventing and Fixing Rust: To combat rust effectively you must remove all traces of rust from the metal surface. This can be done by a number of methods but most commonly it is done by blast cleaning or hand/power tools such as wire brushes or sandpapers.Once removed, the bare metal surface should be re-coated with the same paint specification of the surrounding areas not affected by rust. 
• High-quality rust converters and anti-corrosive paints can prevent future rust by forming a protective (and decorative) barrier.

Moisture and Metal

Moisture is one of the leading causes of rust and corrosion in metal surfaces. When metals are exposed to damp or humid conditions, the presence of water molecules accelerates the oxidation process, leading to rust formation. Moisture can come from environmental exposure, such as rain or humidity, or from condensation in poorly ventilated areas. To effectively protect metal surfaces from moisture, it is essential to use high-quality waterproofing metal paints and ensure proper surface preparation and maintenance.

Areas that may be subject to risk from moisture damage are metal roofing, metal guttering, roofs and walls inside shipping and storage containers/units, garage doors, agricultural machinery, automotive vehicle undersides and rims, metal doors and window (frames), mezzanines, and commercial racking, storage and shelving. 

• Waterproof Paints: High-quality and specialist metal paints available at Rawlins Paints will ensure that moisture cannot penetrate the paint layer and reach the metal - when applied correctly to suitably prepared areas.
• Proper Ventilation: Ensuring areas are well-ventilated to reduce dampness and moisture build-up will vastly improve the lifespan and integrity of metal, and also aid colour retention. For areas where ventilation cannot be improved, you must implement a regular cleaning schedule.

Types of Metal Paints

Choosing the right type of metal paint is crucial for achieving the desired protection and 'aesthetic' results. Metal paints come in various formulations, each designed to address specific needs and conditions. From eco-friendly water-based options to highly durable solvent-based paints, understanding the differences can help you make an informed decision. Whether you need a quick-drying solution for a small project or a robust, chemical-resistant coating for industrial use, there's a metal paint suited to your requirements.

• Water-Based Metal Paints: Eco-friendly, easy to clean, and low odour. Suitable for indoor and outdoor use and DIY projects.
• Solvent-Based Metal Paints: Durable with strong adhesion, ideal for heavy-duty applications and providing excellent resistance to harsh weather conditions.
• One-Pack Products: Ready-to-use paints that do not require mixing. Convenient for small projects and quick touch-ups.
• Two-Pack Products: Include a base and an activator (hardener). When mixed, they offer superior durability and resistance to chemicals and abrasions.
• Epoxy Paints: Exceptional adhesion, chemical resistance, and durability, making them suitable for industrial environments.
• Polyurethane Paints: Tough, durable finish with excellent resistance to weathering, ideal for outdoor applications.
• Alkyd Paints: Durable finish with good adhesion, often used for metal structures and machinery.
• Zinc-Rich Paints: High percentage of zinc, offering excellent corrosion protection for ferrous metals.

Metal Types and Surface Preparation

The type of metal you're painting significantly impacts the preparation process and the type of paint you should use. Different metals have varying properties and susceptibilities to corrosion, requiring specific primers and preparation techniques to ensure optimal paint adhesion and durability. Proper surface preparation is essential to remove contaminants, create a smooth surface, and enhance the bond between the metal and the paint. Neglecting this step can lead to premature paint failure and increased maintenance costs.

In brief:

• Steel and Iron: Remove rust, clean the surface, and apply a rust-inhibiting primer.
• Aluminium: Clean with a suitable solvent and use an etching primer to ensure good adhesion.
• Galvanised Steel: Clean with a degreaser and use a primer designed for galvanised surfaces to prevent peeling.
• Copper and Brass: Clean thoroughly and use an adhesion primer before applying paint.
• Stainless Steel: Clean thoroughly. While rust-resistant, a primer can help with adhesion.

Surface Preparation Equipment and Tools

Effective surface preparation requires the right tools and equipment. Blast cleaning is nearly always the best form of preparation on metal surfaces, but should this not be possible using the appropriate hand and power tools - all available to buy from here - not only makes the job easier but also ensures that the surface is properly prepared for painting. This includes removing rust, dirt, and old paint, as well as creating a profile that allows the paint to adhere better. Investing in quality preparation tools can save time and improve the final outcome of your painting project.

• Wire Brushes: For removing loose rust and paint.
• Sandpaper: For smoothing surfaces and improving paint adhesion.
• Degreasers: To remove oils and contaminants.
• Rust Converters: To stabilise rust before painting.
• Primers: To ensure good adhesion and prevent corrosion.
• Protective Gear: Including gloves, masks, and goggles.

Application Methods

The method of applying metal paint can significantly affect the finish and durability of the coating. Each application method has its advantages and is suited to different types of projects. Understanding these methods can help you choose the best approach for your specific needs, ensuring a smooth, even finish and optimal protection for your metal surfaces. Whether you prefer traditional brushing, efficient rolling, or advanced spraying techniques, each method offers unique benefits.

• Brush: Ideal for small areas and detailed work.
• Roller: Suitable for larger flat surfaces.
• Spray Gun: Provides an even finish and is efficient for large projects.
• Dipping: Used for small parts and ensures complete coverage.

Specialist Coatings for Different Applications

Certain metal surfaces and environments require specialised coatings to ensure maximum protection and longevity. From cladding and metal roofs to industrial floors, each application demands paints with specific properties. These specialised coatings are designed to withstand extreme conditions, such as UV exposure, temperature fluctuations, and high wear. Selecting the appropriate coating for your application ensures that the metal remains protected and maintains its integrity over time.

At Rawlins, these specialist coatings are in focused categories:

• Cladding Paints: Requires durable, weather-resistant paints to protect against the elements.
• Metal Roof Paints: Need flexible, UV-resistant paints to cope with temperature fluctuations and prevent leaks.
• Metal Floor Paints: Require hard-wearing, abrasion-resistant paints to withstand heavy foot and vehicle traffic.
• Automotive, Car and Vehicular Paints: Specialised automotive paints are formulated to provide high durability, resistance to chemicals, and protection against environmental factors. These coatings are ideal for car bodies, chassis, and exhaust systems.
• Agricultural Paints: Equipment used in agricultural settings faces unique challenges, including exposure to soil, chemicals, and varying weather conditions. Paints designed for agricultural use offer robust protection to extend the life of machinery and structures.
• Intumescent Paint for Steel: Intumescent paints provide fire protection for steel structures. When exposed to high temperatures, they expand and form a protective char layer that insulates the steel and prevents structural failure during a fire.
• Marine Environments: Marine paints are specifically formulated to withstand the harsh conditions of saltwater environments. These paints provide superior protection against corrosion, barnacle growth, and UV damage, making them ideal for ships, docks, and offshore structures.
• Heat Resistant Paints: Heat-resistant paints are designed to withstand high temperatures without degrading. These paints are essential for applications where metal surfaces are exposed to extreme heat, such as industrial machinery, exhaust systems, BBQ’s and wood burning stoves.
• Tank and Pipe Lining: Specialised coatings for tank and pipe linings offer excellent resistance to chemicals and abrasions. These linings protect the internal surfaces of tanks and pipes, preventing corrosion and contamination.
• Chemical Resistant Paints: In industrial environments where exposure to harsh chemicals is common, chemical-resistant paints provide a durable barrier that protects metal surfaces from corrosion and chemical damage.

Common DIY, Commercial, and Industrial Projects

Metal paints are versatile and used across various sectors. From home improvement to large-scale industrial applications, understanding the specific needs of each project type ensures you choose the right products and methods. Whether you're refurbishing a garden gate, painting office furniture, or protecting structural steel, the right metal paint can provide long-lasting protection and an attractive finish.

DIY Projects

DIY enthusiasts often use metal paints for a variety of home improvement tasks. Ensuring the right preparation and paint choice can make these projects successful and durable.

• BBQs: High-heat paints to withstand temperatures and prevent rust.
• Radiators: Use radiator-specific paints that can endure high temperatures without peeling or yellowing.
• Garage Doors: Durable, weather-resistant paints to protect against the elements.
• Gates and Fences: Anti-corrosive paints to prevent rust and maintain appearance.
• Garden Furniture: Weather-resistant and UV-protected paints to ensure longevity and maintain colour.

Commercial Projects

Commercial settings often require paints that combine aesthetic appeal with durability. High-quality metal paints can enhance the look of commercial properties while providing protection.

• Shop Fronts: Attractive, durable finishes to enhance curb appeal and protect against weather.
• Office Furniture: Paints that provide a professional look and withstand daily use.
• Signage: Weather-resistant and UV-protected paints to maintain visibility and appearance.

Industrial Projects

Industrial environments demand paints that can withstand harsh conditions and heavy use. Specialised metal paints are essential for protecting valuable equipment and infrastructure.

• Machinery: Durable, chemical-resistant paints to protect against harsh industrial environments.
• Bridges and Structural Steel: Anti-corrosive, weather-resistant paints to ensure longevity and structural integrity.
• Marine Equipment: Waterproof, salt-resistant paints to protect against harsh marine conditions.

Automotive Requirements

Automotive applications require paints that can withstand high temperatures, exposure to the elements, and physical wear. Selecting the right metal paint for automotive use ensures durability and longevity.

• Exhaust Pipes: High-heat resistant paints to withstand extreme temperatures and prevent rust.
• Bodywork: Durable, flexible paints that can withstand weather and physical wear.
• Undercarriage: Anti-corrosive paints to protect against road salt and moisture.

Touch-Up Projects

Maintaining the appearance and protection of painted metal surfaces often requires periodic touch-ups. Using the right tools and techniques for touch-up projects ensures a seamless finish and prolongs the life of the paint job. Understanding how to match colours, apply small amounts of paint accurately, and use paint samples can help achieve professional results.

• Using Paint Samples: Test small areas to ensure colour accuracy and adhesion.
• Colour Matching: Use spectrophotometers or take samples to a paint store for precise matching.
• Tips and Suggestions: Clean and sand the area, apply primer if needed, and use small brushes or touch-up pens for precision.

Industry Approved Systems

Industry standards and approved systems ensure that metal paints meet specific performance criteria and are suitable for their intended applications. Understanding these standards can help you choose products that provide reliable protection and comply with regulatory requirements.

• NORSOK: Standards for the offshore oil and gas industry, ensuring durability and protection against harsh marine environments.
• Highways Agency: Specifications for paints used on infrastructure like bridges and roads to ensure safety and longevity.
• ISO 12944: International standard for corrosion protection of steel structures by protective paint systems.
• Network Rail: Standards for paints used in railway environments to withstand mechanical and environmental stress.
• MED (Marine Equipment Directive): Ensures safety and performance of paints used on ships and marine structures.

Stages of Metal Paints

The painting process involves several stages to ensure a durable and attractive finish. Each stage, from surface preparation to the application of topcoats, plays a crucial role in the overall performance of the paint. Manufacturers will detail recommended system products within data-sheets, but if you do require support on whether a product may be suitable for use with a coating/primer/cleaning item you already have, please contact our Technical and Product Support Team for advice. Understanding these stages helps achieve the best results and extends the lifespan of the painted surface.

• Cleaning and Surface Preparation: Remove rust, dirt, and grease to ensure a clean surface for painting.
• Primers: Provide a base layer that enhances adhesion and prevents rust.
• Intermediates and Undercoats: Additional layers to build up protection and ensure even coverage.
• Direct to Metal or All-in-One Metal Paints: Formulated to adhere directly to metal without the need for a primer.
• Decorative Topcoats: Final layer providing the desired colour and finish, enhancing durability and appearance.

Paint Sheen Finishes for Metal

The sheen of the paint affects both the appearance and the performance of the coating. Different finishes offer various levels of gloss and reflectivity, which can enhance the look of the metal and provide additional protection. Selecting the right sheen is important for achieving the desired finish for different project types and requirements.

• Matt: Non-reflective finish, hides surface imperfections.
• Satin: Slight sheen, balances between matt and gloss.
• Gloss: High shine, enhances colour and durability.
• High-Gloss: Maximum shine, very durable, and easy to clean.
• Metallic: Shimmery, reflective finish that mimics the look of actual metal, often used for decorative and automotive applications.

Metal Paint FAQs

What is the best way to apply metal paint?

The best method depends on the project size and type. Brushes are ideal for small, detailed areas; rollers are suitable for large, flat surfaces; spray guns provide an even finish and are efficient for large projects. Ensure you follow the manufacturer's instructions for optimal results.

How do I prepare a rusty metal surface for painting?

For best results blast clean to the relevant industry standard as per the manufacturers guidelines of the metal paint you’re intending to use. If blast cleaning isn’t possible, select a metal paint that is OK to be applied to hand/power tool cleaned metal. Thorough scraping, wire brushing, disc sanding, etc. to remove all loose scale, rust and other material. Dust off and clean the surface with a degreaser to remove contaminants. Immediately begin to apply the chosen paint system so no flash rusting occurs on the newly, bare prepared metal.

Can I paint over old metal paint?

Yes, as long as the old paint is in good condition, well adhered and is compatible with what you intend to apply next. Abrade the surface of the existing paint with sand paper to ensure proper adhesion and remove any flaking paint. If necessary, apply a primer to any areas back down to bare metal before applying your new topcoat over everything.

What is the difference between water-based and solvent-based metal paints?

Water-based paint uses water as the primary solvent to dissolve the binders and pigments. It typically contains acrylic, vinyl, or latex resins as binders, along with various additives to improve performance. This type of paint is easy to apply, dries quickly, and typically can be cleaned up with soap and water. Water-based paints usually have low odour and emit fewer volatile organic compounds (VOCs), making them a more environmentally-friendly choice, and possibly more suitable for indoor use.

Solvent-based paint, also known as oil-based paint, utilises organic solvents like mineral spirits or turpentine to dissolve its binders and pigments, which are often alkyd, polyurethane, or epoxy resins. Solvent-based paints may require more careful application and cleanup with chemical solvents. They can dry more slowly than their water-based counterparts which can be advantageous for achieving a smooth, glossy finish where desired. However, they can also have a strong odour and higher VOC emissions, posing greater health and environmental risks, especially if applying indoors.

Check out our blog post 'What Is The Difference Between Water-Based And Solvent-Based Paints?' for more info.

Do I need a primer for all metal surfaces?

Not always. Some high-adhesion paints can be applied directly to metal surfaces without a primer. However, primers are recommended for better durability, especially on metals like aluminium, galvanised steel, and rust-prone ferrous metals.

How long does metal paint take to dry?

Drying times vary depending on the product and environmental conditions. Typically, metal paints dry to the touch within a few hours, but full curing can take up to 24 hours or longer. Always refer to the manufacturer's instructions for specific drying times.

Can metal paint be used on outdoor furniture?

Yes, ensure you choose a paint with UV resistance and waterproof properties to protect against weather conditions. Outdoor-specific metal paints are formulated to withstand the elements and provide long-lasting protection.

Is metal paint waterproof?

Many metal paints have waterproof properties, protecting the substrate from moisture and preventing rust. Always check the product specifications to ensure the paint meets your waterproofing needs.

How do I choose the right colour for my project?

Consider the environment and desired appearance. Our store offers over 4,000 colour options, including RAL and BS standard colours. You can use paint samples and colour matching services to ensure you get the perfect shade.

What are the benefits of two-pack metal paints?

Two-pack paints, which include a base and an activator, offer enhanced durability, chemical resistance, and abrasion resistance. They are ideal for industrial applications and environments where high performance is required but are generally only suitable for professional use.

Can metal paint prevent rust?

Yes, anti-corrosive metal paints are designed to prevent rust by creating a protective barrier that prevents oxidation. Regular maintenance and proper application ensure long-lasting rust protection.

How do I clean metal surfaces before painting?

Use a proprietary cleaner/degreaser designed for use on metal remove oils and contaminants. For heavily contaminated surfaces, a solvent cleaner may be necessary. Always be sure to remove thoroughly and let the surface dry completely before painting.

Can I use metal paint on non-metal surfaces?

Some metal paints can be used on other surfaces such as wood or plastic, but it is best to check the manufacturer's recommendations. Specific formulations are designed for multi-surface applications.

What is a rust converter primer?

A rust converter primer chemically converts rust into a stable, paintable surface, allowing you to paint over rust without removing it completely. This primer stabilises the rust and prevents further corrosion. Generally these are only used/recommended when the necessary preparation cannot be carried out due to access or other extenuating circumstances.

Are there metal paints that don't require a primer?

Yes, some paints are formulated for direct application to metal without a primer. These are often labelled as "direct-to-metal" paints and are designed to provide strong adhesion and rust protection.

How do I store leftover metal paint?

Keep any leftover paint in the original, sealed container and stored in a cool, dry place. Avoid exposure to extreme temperatures to maintain its quality. Properly stored metal paint can have a shelf life of 2-5 years depending on the product/brand - check the product data sheet for details.

What are metallic finishes?

Metallic finishes provide a shiny, metal-like appearance, often used for decorative purposes on items like furniture and automotive parts. These finishes can enhance the visual appeal of the painted surface.

Can I mix different brands of metal paint?

It's not recommended to mix different brands of metal paint, as compatibility issues may arise. Stick to one brand to ensure consistent performance and a uniform finish.

How many coats of metal paint should I apply?

This will be dependent on what you are painting, your chosen application method and how long you want the system to last. Typically, it will range anywhere from one to four coats for optimal coverage and protection. Follow the manufacturer's instructions for specific application guidelines to achieve the best results.

What is the shelf life of metal paint?

Most metal paints have a shelf life of 2-5 years if stored properly in an original sealed container away from extreme temperatures. Always check the product label for specific storage instructions and shelf life information.

If you have a question which has not been covered in these FAQs, or have a specific project requirement, please use the search option on the site, this category’s sidebar filter or sub-category links, or contact our Technical and Product Support Team by phone, email or live chat.

What Rawlins’ Customers Say:

Don’t just take our Technical Support Teams’ words for it, here’s what our customers have to say about metal paint they have purchased from our store:

Quite simply the best paint I have purchased (Rust-Oleum CombiColor Original). Far better than any of the so called "5 year life" paints you can buy at the big DIY stores. Very quick and efficient service. Customer feedback from Brian C on Trustpilot

Unaware of this paint (Rust-Oleum 7500 Alkythane) until suggested by Rawlins' Technical Support, we won’t use anything else now on steel work or cladding. Great opacity and touches up really well too. Customer feedback from Ronald M on Trustpilot

Excellent product (Fosroc Galvafroid) that does exactly what it says on the can! Used to protect an inserted mild steel section supporting a timber building ground level replacing rotten timber structure. Customer feedback from Paul C on Trustpilot

Brilliant paint (Rust-Oleum Mathys Noxyde Peganox). Went on to girders easily and very effectively. Superb flow and easy to brush to a good finish. Looks like it will really last. Customer feedback from James B on Trustpilot

The information provided above is a basic overview and is intended as general information only. It is not advice, and is given without warranty. You should always refer to the relevant data sheets and our Technical Team prior to purchase or use of any products.