A NATO-spec jerry can is one of the most useful items you can carry on a serious overland trip — and one of the most dangerous if misused. Fuel is flammable, vapors accumulate in enclosed spaces, and static electricity can ignite vapor during transfer. Here's the complete safe-use guide.
Before You Fill
Inspect the can every time before use:
- Check the lever clamp and rubber seal for cracks or deformation
- Check the body for dents, rust, or damage
- Confirm the vent (on the spout or cap) is clear and functional
- If the seal is deteriorated or the can leaks during filling, stop immediately
Never use a damaged jerry can. A leaking steel container carrying 20L of petrol or diesel is a fire hazard that no trip is worth.
Filling at the Service Station
Step 1: Remove the can from the vehicle before filling. Never fill a jerry can while it's mounted on a vehicle rack or inside a vehicle. Ground it against static buildup. If filling from a bowser, place the can directly on the ground — rubber mats and truck beds can accumulate static.
Step 2: Make metal-to-metal contact before opening the nozzle. Touch the fuel nozzle tip to the inside rim of the can opening before pressing the pump trigger. This equalises the charge between the pump and the can and prevents static spark ignition. This step matters most in dry, cold conditions and high-flow pumps.
Step 3: Fill slowly to reduce vapour generation. Insert the nozzle as far as possible into the can and fill at moderate flow rate. This minimises fuel splashing and reduces vapour generation at the opening.
Step 4: Leave a small expansion gap. Don't fill to the absolute brim. Leave about 5% of the can volume (approximately 1L for a 20L can) for thermal expansion. In hot Australian conditions, a fully sealed 20L can in direct sun will pressurize significantly. The NATO-spec venting systems handle this, but starting with slight headroom reduces pressure load.
Step 5: Lock the cap and clamp firmly. Close the spout, lock the lever clamp, and confirm no fuel is seeping from the seal before remounting on the vehicle.
Storage on the Vehicle
Outside mount, away from heat sources: Jerry cans must be mounted outside the cabin, never in enclosed spaces. The correct location is a rear bumper carrier, underbody carrier, or roof rack with adequate ventilation and distance from exhaust. Steel NATO cans with properly seated seals tolerate heat well, but they should not be in direct proximity to exhausts.
Fuel type labelling: Always mark cans clearly with fuel type. The NATO colour standard is red for petrol, yellow for diesel, and green for water — though not all Australian cans follow this exactly. Use a label or permanent marker. Putting petrol in a diesel vehicle is a costly mistake when you're 200km from a mechanic.
Check mounts regularly: Corrugated tracks and rock shelves put enormous stress on jerry can mounts. Check that mounting brackets are secure and cans aren't shifting after rough terrain. A loose 20L steel can that comes free at speed is dangerous.
Pouring Safely
Use a quality spout: Genuine Wavian jerry cans ship with the NATO-spec flex spout. Use it. Improvised containers, household funnels, and cut bottles are slower, spill more, and don't seal the can correctly.
Pour away from ignition sources: Never pour fuel within 5m of a running engine, naked flame, or lit cigarette. Turn the engine off completely and wait 30 seconds before starting the transfer.
Control static during pour: Touch the metal spout to the vehicle's metal fuel filler neck before inserting it. This grounds both surfaces and eliminates static differential before fuel starts flowing.
Seal the filler cap before restarting the vehicle: Make sure the vehicle's fuel cap is fully closed before restarting. Fuel vapor at the filler cap is ignitable; vapors from a loose cap can enter the engine bay.
Long-Term Storage
Petrol degrades in roughly 3–6 months without a fuel stabiliser. Diesel lasts 6–12 months. For extended storage (more than one trip), use a fuel stabiliser, label the can with the fill date, rotate stock, and inspect seals before each season. Steel NATO cans stored correctly last decades — the US military still uses cans from the 1970s.
Buy genuine Wavian NATO jerry cans at RV Parts Giant.