After you have bought a used shipping container for home or business use, what are the next steps before you start using your container? If you have purchased an older sea container with many years of service, you probably want to spend some time refurbishing the container to ensure that it is clean and ready. You can save yourself some money by choosing an older shipping container unit and then spending some time and effort to spruce it up and make it look almost brand new. The cost of refurbishing your used container can be done for under $500 (not including the price of the container). wwt shipping containers

In this article, we will cover the best ways that you can refurbish your used Conex box and get it ready for whatever purpose you have in mind. Topics that we will cover in this article:

How to clean your container, potential contaminants to look out for, flooring options for your shipping container, rust identification and treatment, preparation for painting, selecting the right type of paint for your container, and the correct procedure for painting your Conex container.

Let’s get started!

Options for refurbishing your used shipping container

Refurbished shipping containers are more economical than the newer one-trip units. Depending on your intended use, this might well be the best option for you. If you are not using your unit for a shipping container business that requires a new appearance, then you will save money and get a perfectly serviceable used unit that you can then refurbish.

Your used steel container will likely show some wear and tear on the exterior surfaces. Containers incur dings, scrapes, markings, discoloration, and dents during their long ocean voyages that detract from the aesthetic look of the container. The good news is that your container may look weathered, but its wind and water-tight features are still intact and the structure of the floor and walls are still solid.

By the time a sea container comes out of international cargo shipping service, it may be between 10-15 years old. The container will have some dents, scrapes, and display surface rust. Refurbishing your cargo container will add years to the life of your container and also give your used container a considerable improvement in its aesthetic appearance

Home and Business Applications 

Most of Conex Depot’s customers buy a used shipping container to use for home or business storage, there are multiple possible applications. For example, your home requires more storage space and a container can act as a storage shed or garage area. During home renovation projects, your materials, equipment, and supplies can be stored safely and dry at your location.

A common business use is using the shipping container as convenient storage for their inventory. As the steel containers are secure and watertight, they provide an easy alternative for business storage. Using a Conex box for home and business storage doesn’t require as much effort to refurbish as a container that will be used as a retail or office space, but performing some basic refurbishing is both easy and important.

Refurbishing is simpler than actually renovating the container. Modifications like door installations, vent inserts, insulation, and electrical access are more involved processes and we won’t be going into these areas in this article.

Cleaning and Prepping Your Shipping Container

The first thing that you are going to want to do is clean your used cargo container. The basic steps to cleaning your used Conex box are:

1)  Inspect the interior and exterior
A simple examination of your container may reveal dirt buildup, dust, seeds or leaves, liquid stains, and odors. In most cases, a simple sweeping out of the container will take care of any accumulated debris. You are also looking for any signs of rust that we will tackle later in the refurbishing. In cases of heavy dust build-up, a leaf blower is an efficient way to clear the particles out of the space.

2)  Pressure washing
In most cases, using a garden hose to wash the surfaces inside the container will be sufficient to clean it of dirt. If your container floor shows accumulations of previous leaks of unidentified liquids and staining that resist the initial floor washing, it may be necessary to spray down your container with a more powerful pressure washer.

3)  Cleaning products
As far as which cleaning products to use, there are no hard rules about what you can and cannot use. If a cleaning product (for example Pine Sol, or Lysol) product is appropriate for cleaning use on metal surfaces you will have no problems using it to clean your shipping container.

A useful and readily available cleaner to assist with cleaning resistant stains and odors is distilled white vinegar. If the stains in your container are not coming out with the simple water spray down, you can try using a spray bottle with a slightly diluted vinegar solution and spray it on the problem areas. Allow the vinegar to sit and work on the stain for a few minutes and then wipe it clean.

Shipping container contamination problems

Your used shipping containers may have a long and varied list of different cargo that it has carried in their history. It likely has traveled from many different locations in the world that have different climates and may have been exposed to different types of contaminants.

The shipping container has spent significant transit time on the ocean, allowing the opportunity for various types of contaminants such as bacteria and mold to form and grow. Shipping containers come into contact with a variety of liquids, pollens, bacteria, and chemicals during their ocean trips. This is especially prevalent in humid and warmer climates.

It is important to know that the shipping industry DOES inspect containers for contamination before certifying them for cargo shipping. Local shipping inspectors place emphasis on ensuring that containers with possible contaminants or pollutants are flagged and treated through inspection and fumigation requirements when a problem has been identified. Therefore it’s unlikely that your used shipping container is contaminated with any toxic and harmful substances that you should be worried about.

Possible contaminants that could be in a container:

Insects – Any time organic materials are shipped, insect pests that feed on their cargo may be present

Pests – Mice and rats are attracted to the dry environment of a container – especially if they are carrying any type of food for the pests. If the container has remained open for any period of time while being loaded, rodents may have entered the container.. Rodent droppings may contaminate the container and the goods inside of it.

Plants – A cargo container that has been used to transport produce or any plant matter may leave behind seeds, mold, or pollen residue and must be thoroughly cleaned.

Chemical Residues – Oil or other chemical spills that may have occurred during shipping as well as leaks from improperly stored machinery or materials are important to look for and clean properly.

Mold Growth – Mold is a problem especially prevalent in the container interior that has wet or damp surfaces. In the dark, humid conditions inside a sealed Conex container, the perfect conditions exist for the growth of undesirable molds.

Shipping Container Flooring

Depending on how your shipping container is equipped when it arrives, you may wish to put a new type of floor covering in your container. The most popular floor treatment for a used cargo container is to seal the floor with an epoxy coating.

Epoxy coating adds an extra protective seal on the container floor..The addition of an epoxy coat helps a slip-resistant surface on the floor and adds a nice clean surface.

Guide To Painting Your Shipping Container

A fresh coat of paint can transform a dirty-looking, tired old box into something that looks sparkling new, appealing to the eye, and ready for whatever project you have in mind.

There are several steps involved in repainting your used shipping container.

Dealing with shipping container rust

Shipping containers that have been in use over many years eventually develop rust as a result of sustaining damage during transit. When the surface of a container is damaged, the protective coating on the container is removed and exposed to the elements which allow the oxidation reaction that forms rust to happen.

Shipping containers are constructed out of corrosion-resistant steel called Corten steel. Cor-ten steel was developed by the United States Steel Corporation in 1930 and the name is a contraction of “[cor]rosion resistance” and “[ten]sile strength”. Cor-ten steel has enhanced corrosion resistance provided by a protective oxide film on the steel surface which inhibits corrosion.

Prior to painting, any surface rusted patches must be treated. Inspect all over the shipping container that is heavily used, especially areas like the doors, hinges, and corners.

There are 2 types of rust on a steel cargo container. Surface rust (which is non-structural) and superficial. The second type is the more serious structural rust. Structural rust has penetrated below the surface of the metal and can negatively affect the shipping container’s structural integrity. If load-supporting structures are compromised by heavy rust, the container can warp and walls can start to buckle.

Shipping Container Rust Treatment

Rust treatment before applying paint to the shipping container is essential. You can’t ignore rust and simply paint over rusted patches. The rust must be removed and the metal surface cleaned.

The most expensive and heavy-duty method of removing rust from your shipping container is to have the rust sandblasted away. Fortunately, you likely don’t need this serious of a rust treatment solution. Additionally, sandblasting will strip off all of the protection provided by the original factory marine-grade paint job. It is not likely that a do-it-yourself paint job will provide the same level of protection as the original factory coating. Treating rust patches, priming, and painting over the existing problem areas are the best solution for you.

Treating rusted areas on your shipping container

We recommend that you remove small areas of rust using a wire brush and sandpaper. Clear the rust from the problem areas with a wire brush first.  Remove any remaining traces of rust with the sandpaper as the second step.  Once all visible traces of rust have been removed, finish cleaning the metal with plain, household vinegar.

Select the correct paint

The type of paint you should use to repaint your used shipping container is determined by the intended use of your container. The effect of a fresh coat of high-quality paint can totally transform the appearance of your used container.

We highly recommend that you use an industrial-grade alkyd enamel paint. This paint will give a hard and shiny finish that will last from five to ten years.

The good news is that alkyd enamel paints are not expensive. Alkyd enamel paint is made of alkyd resins in a chemical solvent. The paint dries as its solvent base. evaporates, leaving behind the alkyd resins. The resins cure as they air dry and oxidize, leaving a very durable and shiny finish to your metal Conex box.

One shipping container supplier recommends that you paint your used shipping container with marine-grade paint. This type of paint is exceptionally durable and provides strong protection from the seasons. Commonly acrylic marine-grade paint is used with a satin finish.

If you intend to use your container for heavy industrial uses, you should consider using polyurethane paint. This type of paint is intended for industrial use and may last for many years. Note that using this type of paint requires special procedures for safely mixing and applying. Consulting with a professional painter is recommended if you decide to use polyurethane paint due to the complicated nature of working with it.

As a rough estimate, your 20 ft container will need at least four gallons of paint, and eight gallons to cover a 40 ft container with a single coat of paint.

Painting your shipping container

Before painting with your alkyd enamel paint it’s recommended that you apply a rust-inhibitive primer. Priming metal surfaces before applying your paint is almost always advised, as it will improve adhesion and help prevent any rust from growing under the new paint.

Water-based primers are not recommended for use on metal surfaces. Instead, look for rust-inhibiting primers, galvanized primers, and iron oxide primers options. Primer also helps the paint stick to metal. Priming and painting can be done with either a roller or spray gun / compressed air sprayer. The most popular neutral colors of paint seem to be different hues of gray and brown.

As a final tip, we recommend that you paint the container on a dry, sunny morning. The paint will need a full day to set properly. Rain will delay and prevent your paint from setting correctly. Containers painted in the afternoon are more likely to get covered in dew before the paint fully dries. If water becomes trapped beneath the surface of the paint, you will have an unpleasant surprise when it creates blisters on your new paint job.