Don’t Trust The Rust
Whether you’re buying or renting, your shipping container is a valuable investment. To maximize its lifespan, regular maintenance is key to preventing rust and corrosion, the main threat to container longevity. While containers are made with corten steel that slows down rust, it’s crucial to address rust spots promptly before they lead to holes.
To protect your container, guard it against moisture and promptly address dents for a longer-lasting, better-looking container. Rust development in shipping containers is primarily linked to moisture. Used containers may exhibit surface rust from years of overseas travel and dings from heavy equipment use. Even if your used container is guaranteed to be wind and watertight with no holes or leaks, neglecting these rust spots and dents over time can lead to issues.
Your best protection is to purchase a one-trip container with minimal damage, however, if that is not in your budget there are some things you can do to prevent further rust damage. This is especially important if you live in a wet climate or if you place your container on soft or unpaved ground. These are some tips for shipping container rust prevention:
1. Keep Your Container Dry To Keep It From Rusting
The best approach to prevent your container from rusting is to keep it dry and away from water or any moisture. These are some simple tips you can use to limit your container from moisture. Protecting your container from wet and harsh weather, as well as long-term water exposure from trees or wet ground, is important.
2. Tarp Protection
The key to preventing rust on your container is to cover it with a plastic tarp when not used. This shield is effective in rainy or snowy weather, safeguarding your container from rain, hail, snow, and strong winds that can cause damage. Taking this precaution ensures long-term protection for your container.
For added convenience, use stakes to create a tent-like structure for easy access. Tarps require no cleaning and only need replacing if significantly damaged. This method also maintains privacy for your container and its contents.
3. Keep Your Container Off Soft Or Wet Ground
Placing your container on a concrete slab will protect the bottom of your container from being in contact with moisture over time. However, if your container is placed on soft or wet ground such as dirt, grass, gravel, or sand you can lift it off the ground to prevent direct moisture to the bottom of your container that may cause erosion and rust.
We recommend placing your container on top of two railroad ties, one at each end. Railroad ties are treated and can withstand the elements such as water and bugs. Raising your container off the soft ground will allow air to flow underneath your container so that it dries out if it gets wet.
4. Keep Your Container Away From Potentially Wet Areas
If you are placing your container in an area with no overhead protection it is important to keep it away from areas where there can potentially be extreme moisture such as underneath a large tree or adjacent to a roof that can drain water onto the roof of the container. If you must place your container under a tree then we recommend trimming the branches to make sure your container can dry off quickly after rain or snow.
5. Gabling The Roof
Some used shipping containers may have small dents on the roof from stacking during shipping or heavy handling. These concave dents can lead to water pooling and rust, potentially causing leaks.
One way to prevent pooling is by gabling the roof, a simple process using a 4×4 wood plank and a jack. Locate the low spot, place the plank there, and push it up with the jack to allow water runoff. Regular roof inspections, especially post-rain or snow, are crucial.
6. Power Wash Caked On Mud
Containers may sometimes have caked-on mud that builds up in storage at the depot or after rainy or wet weather. Removing this dirt before it causes rust in the container is important. Power washing the container with a hose nozzle that produces a strong stream of water is the most effective way to do this. Power washing also helps to prep your container before you paint or perform any other maintenance to the container.
7. Remove Surface Rust Immediately
A used container will likely contain some surface rust. The good news is that most of the surface rust has not yet reached the internal layer of the container, and is still treatable. The bad news is, if it remains untreated it will inevitably create a hole over time.
If the rust is minimal you can use a wire brush to scrape away any visible surface rust. Follow up with a damp cloth to wipe away any of the scrubbed particles.
If the rust goes a bit deeper than the surface layer then you can use a wire wheel to remove the rust. Wire wheels are also what you would use to prep the container before painting it.
8. Repair The Roof Dents to Prevent Water Pooling
Dents in the roof are more susceptible to rust and potential holes for two reasons. One, most people don’t regularly inspect the roof of the container so damage can often be overlooked and two, water can pool on the container roof and can take a long time to dry on its own. The longer the water sits on the roof the more likely it is to cause rusted areas and holes in the container.
Filling in the roof dents is important to prevent water from pooling. The optimal method for this is to use Bondo to fill in the dents.
Filling the dents will make the surface flat minimize water from pooling and allow the roof to drain properly. Be sure to scrape off the existing rust with a wire brush or wheel before applying the Bondo.
9. Spot Treat The Rust With Spray On Primer
If you’re not quite ready to repaint your container you can spot-treat the rust spots to prevent the rust from spreading. A great way to do this is with a spray-on primer made especially to protect metal surfaces such as Rustoleum. These primers can be used on rusty metals, provided you prepare the surface by removing existing rust so that the primer adheres to it properly. The primer will aid in protecting against further rust.
10. Paint Your Container Regularly
The best offense against container rust is to regularly paint your container. Before painting the container it’s important to properly prepare it by power washing it, scraping surface rust with a wire or wheel brush, filling in the roof dents with Bondo, and painting the rust spots with Direct to Metal (DTM) Primer. Although the original manufacturer paint used is made especially for metal, regular house paint will work. See “How to Paint Your Shipping Container” for a detailed step-by-step guide to painting your container.
11. Paint the Roof And Gaskets Regularly
The areas most susceptible to rust on your container will be the roof and doors. As discussed previously, if the roof does not drain properly water sits and creates rust.
This is also applicable to the doors surrounding the gaskets. Water traps underneath the door gaskets and stays wet for long periods, causing rust to form. Painting the roof and anything in contact with the door gaskets regularly is important, even more often than painting the entire container.
12. Regular Maintenance
The lifespan of your container is directly related to how well you maintain it. If you treat small scratches, dents, and rust spots before they become a problem then you will have a sturdy and watertight container for years to come. The overall key to preventing rust from overtaking your container is to keep it dry. Here are some helpful and simple maintenance tips to follow.
- Treat tiny scratches immediately with sandpaper or even a hard toothbrush if you don’t have a wire brush available.
- Use trailer tape to cover even the tiniest holes in your container. Trailer tape has an aluminum backing that is made especially for metal buildings, trailers, pipes, etc., and can work to seal seams and small holes in your container.
- Using caulking for cuts and small holes in your container can also aid in sealing your container and stopping tiny holes from becoming a problem.
- Repairing large holes can be expensive and may require a professional welder and patchwork that can ruin the integrity and look of your container. This can be avoided with some proper TLC. Although all our containers are guaranteed to be wind and watertight, we recommend checking your container upon delivery to ensure that the container is in proper wind and watertight condition.
Here’s a video to learn more information about treating rust spots on your shipping container:
Conclusion
In conclusion, preventing rust in shipping containers is crucial to ensure the longevity and structural integrity of the container. By implementing a combination of proactive measures and regular maintenance, you can significantly minimize the risk of rust development.
On-Site Storage Solutions
For expert advice on rust prevention and container maintenance, contact On-Site Storage Solutions at (888) 405-8772. Let us help you keep your shipping containers rust-free and in optimal condition for your storage needs.
FREQUENTLY ASKED QUESTIONS
The most recommended paint for shipping containers is marine-grade waterborne DTM (direct-to-metal) paint. This paint is specially formulated to endure the harsh shipping conditions, offering exceptional durability and resistance. It provides reliable protection against rust and corrosion while being water-resistant, ensuring long-lasting performance.
To paint a shipping container, start by pressure washing the entire exterior to get rid of any surface dirt or mud. Once the washing is done, wait for the container to dry completely. Then, use a pneumatic paint roller or sprayer to apply the chosen paint.
To clean a shipping container, start by removing any debris and dirt from the surface using a broom or brush. Then, wash the container with a pressure washer or hose and a cleaning solution. Scrub stubborn stains with a sponge or brush. Finally, rinse the container thoroughly and allow it to dry before use.
3 Responses
Timely good advice will always be welcome.
Very useful information….thanks.