Used containers are a great option because they are the most cost effective and there is an abundant supply of these containers on the market. A single shipping container has traveled throughout the world and has been exposed to the marine environment for more than 7-10 years. When the container is moved, the areas where the steel panels are joined together become weakened under stress and the original paint can crack or chip away.
Sooner or later, with time shipping containers will get some surface rust that can turn into deep rust and can compromise your storage solution, if you don’t take care of it from the beginning. Even if you just bought it and it’s wind and water tight or cargo worthy, make sure you give them a coat of paint, just to protect it and extend it’s life. It might be a little bit time consuming, but it’s not so expensive and that way you know for sure you’ve seen it all from the top to the bottom.
Because of being heavily used, water has an opportunity to collect in the corners or underneath the doors and remains stagnant. Painting the shipping containers makes the box more attractive in appearance and provides durability, ensuring the strength and integrity of the metal by keeping it free from rust.
Now is the time to paint your shipping container, don’t wait too long once you get in possession of the unit. Of course cosmetics will change and will look better and blend in with the surrounding area. Besides cosmetics, there is another reason to paint your shipping container. Painting it, will add an extra coat between the steel and the elements, and will slow down the spread of rust and will make the unit last longer in any environment ( humid, dry, snow, rain ).
When your unit is damaged hard, in different ways, these scars can speed up the rotting process if you don’t take care of it right away. You have to understand that, the used units that are out there on the market, they are how they are, “as is”, “wind and water tight” or “cargo worthy”, they are almost in the same boat. They all been decommissioned because they are no longer good to travel overseas, but this doesn’t mean they are not good for storage or different other building purposes, but they have to be maintained or worked on to be kept in a good shape. Don’t expect a used unit to be like new, or that you will be able to immediately store goods in them, without doing a cleaning of the inside, sealing some pin holes with silicone or lubing the doors to work better. Otherwise you could just pay the extra buck and get the flawless one trip / new units out there and you don’t need to work on them at all, since are coming in a very good condition.
When thinking about the units, many customers are concerned with the chemicals used in making the flooring or paint. If you are going to use the unit for storage purpose, there is not much concern over the health risks. However it is not a bad idea to seal off the floor too, with a thick coat of paint, to prevent water damage and toxic fumes from creeping out. Any outdoor paint that is designed to be walked on and withstand the weather of all four seasons would work for the flooring, for example patio or porch paint can be the best choice.
Best option for painting the unit is to use a water based direct to metal ( DTM ) paint. Marine grade DTM paint. Rust-Oleum Marine Paint, Sherwin Williams and Vlaspar are making good marine grade DTM paint, or you can use any other marine grade paint at your convenience, brand is not a big deal as long you get the right product. Of course some brands may be of more quality than others, you can also do a research online and find the best option for you and your budget.
On the rusted spots, use a very interesting substance, called “rust converter”, that transforms surface rust into hard substance and then your unit is ready to be painted. It also prevents the rust from spreading and secured the spot that is already rusted. There are some different brands and options out there, for example POR-15 rust treatment and prevention paint or you can do your research and you can choose from various brands options. We’ve heard good things about POR-15, that has high performance when it comes to rust-preventive coating, because it’s designed to be applied directly on the rusted surface. The POR-15 is ideal because it chemically bonds to the metal, and dries extremely hard, forming a rock hard coating, so it doesn’t chip, crack or peel like regular paint. It also keep moisture away which is getting stronger every time is exposed to moisture. This protective layer can be painted over with your choice of color.
5 Easy Steps to paint your shipping container
The most effective way is to clean up the rust, repaint the shipping container so you have to power wash, sandblast the entire unit, remove the paint, then remove the rusted areas, prime and repaint the container. This would be a completely refurbished container. Sometimes doing this, could be more expensive than buying a used container itself, that’s why we advise to do your maths before, see what is the better option, if you have time or the money to do it, or go with a new / one trip unit option.
If you want to cut some costs, you can just remove the rust and repaint the affected areas, get a wire brush, sandpaper, vinegar and DTM paint. A 20ft container needs around 3-4 gallons of paint. Try to remove as much or the rust as possible. Rub vinegar on those areas you cleaned and leave it to dry out. This will stall the corrosion process. Now it;s time to apply the DTM Paint, ideally , you should apply more than one coat up to 4-5 coats of paint.
1st Step – Clean your shipping container
Preferably with a pressure washer, remove dirt, debris and loose paint chips. Pay close attention to the areas that need special attention. Don’t forget to clean the top of your unit as well as the inside of it.
2nd Step – Clean the rust
Use the low grit sandpaper, steel wool or wire brush – sand all the areas to remove the corrosion or loose paint. If those areas are not well treated , they will compromise the coat of paint later on. Power wash the container again and rub with vinegar or any other rust removal on the areas that need attention. Let the unit completely dry.
3rd Step – Patch the holes or leaks
Sometimes you might find some pin holes around the unit, holes, tears or leaks, fix them with silicone, industry approved fiberglass patches or weld them. You should cover the areas fully and then get them ready for painting.
4th Step – Apply the rust converter
Apply over the rusty areas of the unit with a paint brush, roller or a spray. A rust converter is similar to a steel primer and converts the rust in a hard, paintable surface. It also seals the rusted surface from oxygen, that way it is not exposed anymore. Let the unit dry completely.
5th Step – Paint the shipping container
After the rust converter has dried, using a paint sprayer or a heavy paint roller, is ideal when applying your paint, start painting the unit, cover all surfaces, top, sides and frame. Let the unit dry and enjoy your freshly new painted unit!
Make sure you clean the inside as well, floors, lubricate the doors and make sure everything is cleaned and refreshed for a better experience of using your unit.
We hope you found useful tips and tricks for refreshing your shipping container in this article. We have similar other posts in the Maintenance & Fabrication section of our blog. Feel free to check them out here.
