How to Fix Hard-to-Open Shipping Container Doors

Shipping containers are built to withstand hurricanes and ocean crossings, which means their doors are incredibly heavy. Over time, dust, salt, and light surface rust can build up inside the hinges and locking bars, making the doors nearly impossible to open without throwing out your back.

Fortunately, you don't need heavy machinery or a blowtorch to fix this. With a small ladder and a can of high-quality penetrant like Fluid Film, you can get the heaviest steel doors swinging open with one hand in under 10 minutes.

Fluid Film, Shipping container

You only need three basic items for this quick maintenance routine:

1. Fluid Film: This is a lanolin-based rust preventative and lubricant. Unlike WD-40 (which evaporates quickly), Fluid Film leaves a thick, protective coating that lasts for months.
2. A Small Step Ladder: To safely reach the top hinges and locking cams.
3. A Shop Rag or Paper Towels: To catch any drips.
4. A Shipping Container: I am performing this maintenance on a standard 20ft used conex container (you can view similar heavy-duty models at US Conex).

There are two distinct hardware systems on a container door that cause sticking: the hinges and the locking cams.

1. The Hinges: A standard door has 4 massive steel barrel hinges welded to the side.
2. The Locking Cams and Keepers: These are the metal claws at the very top and bottom of the vertical locking bars that hook onto the container frame.

Before applying any lubricant, use your rag to wipe away any loose dirt, cobwebs, or heavy grit sitting on these metal parts.

Now it is time to lubricate. Shake your can of Fluid Film vigorously.

1. Start with the hinges. Insert the precision straw of the spray can directly into the tiny gaps at the top and bottom of each hinge barrel. Give it a solid 2-second burst of spray.
2. Next, spray the locking cams. Coat the claws at the bottom of the bars.
3. Set up your step ladder. Safely climb up and repeat the exact same process for the top hinges and the top locking cams.
4. Use your rag to wipe up any excessive fluid running down the side of the container so it doesn't attract dirt.

Lubricant won't work if it just sits on the outside of the metal. You have to force it inside the mechanisms.

1. Grab the door handles and firmly swing the door open and closed about 10 to 15 times.
2. Rotate the handles up and down repeatedly. This forces the locking cams to grind against the keepers, drawing the Fluid Film deep into the friction zones.
3. You should feel the door becoming significantly lighter and quieter with every swing.

Pro-Tip: Make this part of your yearly maintenance routine before winter hits to ensure your storage unit is always easy to access!