Despite the damage they accumulate over years of use, secondhand shipping containers for sale are still useful. Cheaper to buy or rent and sturdy enough, these containers show how professional craftsmanship enabled them to survive years.
Nonetheless, wear and tear, such as rust, can still occur. Rust can even become the primary reason customers are unwilling to buy or rent used containers.
Because of that, preventing and treating rust in secondhand shipping containers for sale is a core knowledge all container vendors must have. Let’s see how to do it below!
Also Read: Popular Custom Features for Conex Trailers for Sale
Why Treating Rust in Old Shipping Containers is Critical Before Selling
Rust can be detrimental to anything metal-based, and everyone knows that. However, it goes a bit deeper when it comes to how rust can impact shipping containers:
Preserve Structural Integrity
Rust weakens steel by eating through layers of metal, thus compromising the container’s ability to bear weight or withstand external pressures.
Even minor corrosion around door hinges or roof panels can escalate into costly structural failures during transport or storage.
For example, rust at the base of a container can spread to the floor cross-members and reduce the load-bearing capacity by up to 40%. Structural integrity is especially vital for modified containers like container homes, where safety regulations demand rigorous inspections.
Ignoring rust could lead to legal liabilities or failed certifications and tarnish your reputation as a seller.
Boost Resale Value
Buyers prioritize containers that require minimal repairs. A rust-free unit with intact CSC (Container Safety Convention) certification can sell for 20–30% more than a corroded counterpart.
For instance, a 20ft container with minor surface rust might fetch $1,500, while a fully refurbished, rust-treated unit could command $2,500. Proactive rust management also opens doors to niche markets, such as luxury tiny homes or mobile clinics.
Highlighting anti-rust treatments like zinc coatings or epoxy paints in listings can justify premium pricing and attract eco-conscious clients seeking long-term durability.
Ensure Safety and Compliance
Rust creates sharp edges and weak points, increasing injury risks during handling. Many countries mandate CSC compliance for shipping containers, and untreated rust can void these certifications.
For example, Australia’s Heavy Vehicle National Law requires containers to meet specific structural standards. Here, non-compliant units can face hefty fines or seizures.
Regular maintenance records showing treatments like sandblasting or rust converter applications also build trust with buyers. With these records, you can assure them of the container’s adherence to safety protocols.
Prevent Rust Spread
Like a virus, rust spreads rapidly when exposed to moisture and oxygen. Here, early treatment stops corrosion in its tracks and prevents future repair costs.
A small rust patch on a door hinge, if ignored, can spread to adjacent panels within months. Proactive measures, such as applying rust-inhibiting primers or installing gutter systems, minimize long-term expenses.
For instance, sealing roof seams with marine-grade sealant costs under $50 but prevents water ingress, which could lead to $500+ in repairs.
Build Customer Trust
Transparent maintenance records and rust-free containers establish you as a reliable seller and encourage repeat business and referrals.
How can a seller do it? For example, the seller can offer a 12-month warranty on epoxy coating, assuring buyers of your commitment to quality.
Once they enjoyed the warranty’s benefits, satisfied customers can leave positive testimonials that encourage other customers to
10 Ways to Prevent and Treat Rust in Used Shipping Containers
By now, how do we keep rust from occurring in secondhand shipping containers for sale in our product catalog?
Conduct Regular Inspections and Maintenance
You can start by actively monitoring containers every 3–6 months by focusing on their roof seams, door hinges, and floor edges. Use a flashlight to spot early signs like discoloration, bubbling paint, or flaking metal.
Steps to take:
- Clean surfaces: Pressure-wash interiors and exteriors to remove dirt and salt residues – common culprits in coastal regions. Use biodegradable cleaners to avoid chemical damage.
- Seal cracks: Apply marine-grade polyurethane sealant to gaps around doors and roof panels. For larger gaps, weld steel patches to restore structural integrity.
- Touch-up paint: Use rust-inhibiting primers on exposed metal. Follow with two coats of industrial enamel for lasting protection.
Pro tip: Maintain a logbook documenting inspection dates, findings, and treatments. This record can be shared with buyers to demonstrate diligent upkeep.
Apply Rust Converters
If you’re dealing with active rust patches, convert corrosion into a protective layer with suitable chemical solutions. These solutions can react with iron oxide to form a stable, paintable surface.
Here’s how to apply them in the containers:
- Prep the area: Scrub rusted spots with a wire brush or 80-grit sandpaper. For stubborn rust, use an angle grinder with a twisted wire wheel.
- Apply the converter: Use a synthetic brush for precision or a spray bottle for large areas. Ensure full coverage and let it dry for 24 hours.
- Finish with paint: Top with oil-based enamel or epoxy paint to seal the surface.
Use Zinc-Rich or Corrosion-Resistant Paint
Zinc-rich paints offer cathodic protection, where zinc particles sacrifice themselves to shield underlying steel. If you use the containers in places with considerable weather patterns, use epoxy or zinc-aluminum coatings that withstand salt, UV rays, and humidity.
Pro tip:
- Sandblast heavily rusted areas: This removes 100% of corrosion, ensuring optimal paint adhesion. Partner with local workshops offering robotic sandblasting for uniform finishes.
- Choose high-zinc formulas: Look for paints with 90–95% zinc content for marine-grade protection.
Sandblast Heavy Rust
If the containers suffer from deep corrosion, sandblasting strips rust down to bare metal is important to clear the corrosion. This method is ideal for containers with widespread rust or those being repurposed into offices or homes.
Do the following if you want to sandblast your secondhand shipping containers for sale:
- Prime immediately: Apply rust-inhibitive sprays within 4 hours to prevent flash rust.
- Seal with epoxy: Use two-part epoxy coatings to increase the surface’s chemical resistance.
While you need to spend some money to sandblast the container, such a method adds 10–15 years to a container’s lifespan.
Elevate Containers and Ensure Proper Drainage
Keep containers dry by elevating them 6–12 inches off the ground using concrete blocks, steel beams, or railway sleepers. This prevents ground moisture from seeping into the base.
If you want to set up some drainage system for the container, do these:
- Install gutters: Attach aluminum gutters to roof panels that direct water 3–5 feet away from the container.
- Slope the roof: A 1–2° slope prevents pooling, so you can use wedge-shaped foam inserts under the container’s base for easy leveling.
Apply Protective Coatings
Beyond paint, epoxy coatings and rubberized sealants add an extra defense layer. These are especially useful for containers in coastal or industrial areas exposed to salt and chemicals.
Furthermore, you can use electrostatic sprayers for even coating distribution, which can reduce material waste by 20%.
Cover Containers with Tarps or Shelters
When storing containers long-term, use waterproof tarps or fitted covers to shield them from rain, snow, and UV rays. Ensure covers are breathable to prevent trapped moisture.
Pro tips:
- Secure tarps by using ratchet straps and grommets to withstand 50+ mph winds.
- Use UV-resistant materials like polyethylene tarps with silver coating, which reflect sunlight and reduce heat buildup.
Remove Surface Rust Immediately
At the first sign of rust, act fast to prevent spread. Use a wire brush, sandpaper, or angle grinder with a wire wheel attachment to scrub affected areas.
If you find some stubborn spots, do these to get rid of them:
- Apply phosphoric acid gel that dissolves rust chemically and rinse thoroughly after 15 minutes.
- Use rust-inhibiting sprays that penetrate crevices for deep protection.
Install Insulation to Control Condensation
Condensation inside containers accelerates rust. Spray foam insulation (R-6.5 per inch) seals gaps and regulates temperature, while ply lining adds a moisture-resistant barrier.
You can start by using closed-cell foam that expands to fill gaps, ideal for humid climates. Furthermore, you can use vents like whirlybird vents or louvered panels to boost airflow, ow which reduces moisture by 50%.
Use Cladding for Added Protection
Lastly, exterior cladding (e.g., vinyl, wood, or metal panels) shields containers from weather and physical damage. This is ideal for converted units like homes or retail spaces.
We’ve got some tips for you to add cladding to your secondhand shipping containers for sale:
- Leave a 1-inch gap: Promotes airflow, preventing trapped moisture.
- Use stainless steel screws: Avoid galvanic corrosion caused by dissimilar metals.
Also Read: Metal Cargo Containers for Sale and How to Sell Them: A Guide
Conclusion
By preventing and treating rust in secondhand shipping containers for sale, selling or renting these used containers to your customers won’t be a problem. Tradecorp, for instance, always employs the best measures to prevent and treat rust in all its used containers. Because of that, you can trust Tradecorp to provide the most high-quality used containers in the industry. Contact Tradecorp today to find a used container for you!