How to Paint a Shipping Container — DIY Steps with AU-Climate Tips

Whether you’re refurbishing an old shipping container or undertaking a new conversion project, painting the container makes it look better and last longer.

In this expert guide we’ll walk you through the entire process, from choosing paint to maintaining the finish in the long-term.

Choosing the right primer and paint

Your first task is to select the right primer and paint for the job.

Primer

The primer forms the undercoat, and is particularly important for painting shipping containers, as it protects the steel from corrosion and makes the surface uniform and grippy.

Choose a primer that is:

• Suited to steel (e.g. zinc-rich and epoxy primers)
• Rust-resistant and will guard against corrosion
• Compatible with your chosen topcoat
• Which brings us to the paint that you’ll actually see.

Paint

There are a few different paint options to choose from:

• Marine enamel: Durable, water and salt resistant, great for coastal and wet areas.
• Epoxy coatings: Tricky to apply but super hard-wearing, ideal for industrial sites.
• Acrylic topcoats: UV resistant, easier to maintain, Good for DIY.

You’ll generally need 12-15 litres of paint to cover the exterior of a 20ft container in a single layer, while a 40ft container will require twice as much.

Climate considerations

Different primers and paints are suited to different Australian conditions:

• Coasts: Prioritise anti-corrosion and salt-resistant options.
• Tropics: Choose mould-resistant, high-humidity formulations.
• Inland: UV-resistant paints minimise chalking, peeling and fading.

What you need before you start

• Tools and equipment: Spray gun/rollers, brushes, tray, masking tape, drop sheets, scraper, grinder with a wire wheel.
• Materials: Rust converter, degreaser, primer, topcoat, sealant.
• Safety considerations: PPE, ventilation systems (for interior painting), ladder/scaffolding.

Step 1: Assess and prepare the surface

1. Inspect: Scan the surfaces you plan to paint for defects, rust, pitting and corrosion.
2. Remove stickers, rust: Peel off, grind back, and apply rust converter where needed.
3. Sand: Smooth any rough patches and feather the edges of old paint. Save time by sandblasting.
4. Clean: Wash with degreaser to remove dirt, salt, oil and grime.

Step 2: Apply the primer

5. Apply: Cover the surface evenly using a roller, or better yet a spray gun, paying close attention to nooks and crannies.
6. Check: Look for thin spots, drips or patchy coverage and fix before the paint cures.
7. Dry: Follow the primer manufacturer’s guidelines to ensure the coat is properly cured.

Step 3: Paint the container

8. Assess conditions: Avoid painting in extreme UV, high winds or precipitation.
9. Paint: Follow the same process as the primer – apply, check, dry.
10. Re-paint: Two topcoats are usually enough, but harsh environments/heavy use may warrant more.

Step 4: Seal and maintain

11. Seal: Apply a protective sealant to doors, windows, vents, edges and seams.
12. Inspect: Conduct a visual inspection of your container once a year, looking for chips or rust.
13. Touch up: If you find any issues, fix them straight away so the rust and damage won’t spread.

Tips for a long-lasting finish

Painting a shipping container is a big job, and one that most people won’t want to do over and over again.
The best way to ensure your paint job lasts as long as possible is by taking the time to do a quality job. But the following tips can also help:

• Consider your colour: Lighter colours trap less heat, so are less prone to fading, chalking and peeling.
• Paint on a cool, dry day: Cool, dry weather is ideal for painting, as it ensures the paint adheres and cures properly. Paint won’t last if it’s applied to a hot and/or damp surface.
• Protect your container: Consider placing your container in a somewhat protected area, such as next to a building or under a large (and structurally sound) tree.
• Store spare paint correctly: Keep extra paint on hand for quick fixes in the future, and make sure you store it in a cool, dry, well-protected area.

By investing in the right type of high quality paint, by taking your time, and by following this process to the letter, you’ll create a beautiful, functional and long-lasting shipping container that can form the basis of any number of container conversion projects.

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Step-by-step paint guide for shipping containers: prep, primer, top coat. Australian sun and salt-air specifics. Cost: $300–$800 DIY vs. $2,500 pro.

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