A jerry can full of fuel strapped to the outside of your rig is one of the most useful pieces of overlanding gear you can carry, and also one of the few that can genuinely hurt you if you get careless. Fuel vapor is flammable, fumes are bad to breathe, and a poorly secured can is a hazard on the trail. The good news is that safe handling comes down to a handful of simple habits. Here is how to fill, store, and pour a NATO jerry can correctly so it does its job without becoming a problem.
Filling the Can Safely
Always fill a jerry can on the ground, never in the bed of a truck, on a tailgate, or on any surface lined with carpet or plastic. Static electricity is the real danger during filling. A can sitting on an insulated surface can build a static charge as fuel flows in, and a spark at the filler neck around fuel vapor is exactly what you want to avoid. Setting the can on bare ground lets that charge dissipate safely. Keep the pump nozzle in contact with the metal filler neck while you fill, which keeps everything at the same electrical potential.
Do not fill the can completely to the brim. Fuel expands as it warms, and a can topped off in cool morning air can build pressure and seep as the day heats up. Leave a few centimeters of air space at the top, roughly to where the filler neck narrows. Fill slowly to reduce splashing and vapor, turn off your engine, and never smoke or use a phone near the pump. Once filled, wipe down any spillage on the outside of the can before you load it.
Sealing and Checking the Cap
The seal is what keeps fuel and fumes inside the can during transport, so check it every time. On a genuine NATO can like a Wavian, close the cam-action lever fully until it locks down firmly against the gasket. Give the can a gentle rock and a sniff test before mounting it; if you smell fuel or see weeping, the gasket may be worn or debris may be on the sealing surface. Gaskets are replaceable and cheap, so swap a tired one rather than trusting it.
If your can has a vent or breather cap, make sure it is closed for transport and only opened when pouring. A properly sealed can should carry on its side through rough terrain without losing a drop or filling your gear with fumes. Make the cap check part of your routine every single time you load a can, not just when you remember.
Storing and Mounting on Your Rig
Mount fuel cans on the outside of your vehicle, never inside the cabin or an enclosed cargo area where vapor can accumulate. Use a dedicated jerry can holder that clamps the can firmly so it cannot shift, rattle, or work loose over corrugations. A can that slides around will chafe through its coating and eventually leak. Standard NATO dimensions mean genuine cans fit virtually every quality holder on the market, so there is no excuse for a loose mount.
Keep fuel cans away from heat sources and direct exhaust, and store them upright when possible. For long-term storage at home, keep filled cans in a cool, ventilated, shaded space away from any ignition source, and use a fuel stabilizer if the fuel will sit for months. Steel cans should be stored off bare concrete on a shelf or pallet to avoid trapping moisture underneath, which protects the coating and prevents rust over time. Always store fuel cans separately from any water cans, and color-code or clearly label them so there is never any confusion about which is which.
Pouring Without Spills or Hazards
Pour with the engine off and away from any ignition source. Use the genuine spout that came with the can and make sure the breather tube or vent is open, because the breather is what gives you a smooth, controlled stream instead of a glugging splash-fest. Position yourself upwind so fumes blow away from you, and brace the can against your hip or a knee to control the weight of a full 40-pound can rather than relying only on your arms.
Start the pour slowly to seat the spout in the filler neck, then tip steadily and let the breather do its job. Watch the fuel level and ease off before the tank is full to avoid overflow at the last moment. If you spill, stop, let it evaporate or wipe it up, and do not start the engine until the vapor has cleared. When you are done, close the breather, reseal the cap fully, and stow the spout so it cannot drip. A funnel is worth carrying for awkward filler necks, though a good breather spout usually makes one unnecessary.
The Practical Takeaway
Safe jerry can use is mostly about discipline, not equipment. Fill on the ground to kill static, leave room for expansion, and check the seal every time you load up. Mount cans outside the cabin in a holder that locks them down tight, store them cool and ventilated away from ignition, and keep fuel and water cans clearly separated. When pouring, work upwind with the engine off and let a breather spout give you a clean, controlled stream. Do these things consistently and your reserve fuel will be exactly what it should be: a safe, reliable extension of your range. Start with quality gear from our Wavian collection and build the habits around it.
Shop the parts in this guide
- Wavian 20L NATO Steel Jerry Can, Black (5.3 Gal)
- Wavian 20L NATO Steel Jerry Can, Yellow (5.3 Gal)
- Wavian 20L NATO Steel Jerry Can, Red (5.3 Gal)
- Wavian 20L NATO Steel Jerry Can, OD Green (5.3 Gal)
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