Sometimes a can still feels heavy, you can hear the liquid sloshing, yet pressing the nozzle gives only a hiss or nothing at all. That is not a fault but the result of holding the can wrongly: the propellant ran out before the liquid did. Once the gas is gone, the remaining product cannot be sprayed out.
The reason is simple. With the can upright, liquid rises through the dip tube from the bottom. With the can upside down, it comes straight out through the valve. Held at an angle or horizontally, the end of the tube sits above the liquid, and within seconds the can loses its gas. Here is how to avoid that.
What you will need
Important: Never puncture or open a can to drain what is left: it is still under pressure even when it seems empty. Do not heat it or store it near radiators, stoves or in a car parked in the sun.
Step 1
Shake the can well
Shake the can for a few seconds before every use. This mixes the active ingredients and the solvent evenly, so the product performs the same from the first press to the last.
It is a good habit with any aerosol: most of them need shaking before use.
Step 2
Hold the can upright or upside down
The most common mistake is spraying with the can held horizontally, for example under a car or behind furniture. In that position the dip tube leaves the liquid and mostly gas comes out.
For best results, hold the can upright with the valve on top, or fully upside down. If the spot is awkward to reach, tilt the part rather than the can, or use an extension straw.
Step 3
Classic valve: line up the dip tube
In a standard WD-40 Multi-Use Product can, the dip tube is curved and rests against the bottom edge. Together with the domed base, this lets you draw out almost all the liquid if the tube points to the lowest spot.
Some cans have a blue dot on top of the valve showing which way the tube curves. When only a little is left, tilt the can slightly towards that mark so the tip of the tube stays in the liquid.
Step 4
Smart Straw: turn the nozzle a quarter turn
With WD-40 Smart Straw, check the tube position with a light press. If nothing comes out or only a weak spray, stop at once so you do not waste the gas.
Turn the head a quarter turn to the right and try again. Keep turning a quarter at a time until the product flows in a steady stream. The tube is then at the lowest point of the can.
Step 5
Store and dispose of the can properly
Keep the can somewhere cool. In an unheated garage in winter the pressure drops and the spray weakens, so leave the can in a warm room for a while before work, but never warm it near an open flame or heater.
Do not take an empty can apart. Put it out with metal waste or aerosol packaging collection if your area has one.
Tip: If you often work in awkward positions under a car or machinery, choose
WD-40 Smart Straw: with the extension straw it is easier to keep the can upright and hit the exact spot.
What next
These simple rules make every can last longer and keep the pressure to the end. For a garage or workshop, WD-40 Multi-Use 400 ml is the practical size, and the compact WD-40 200 ml is worth keeping in the boot.
These uses come from the experience of WD-40 users in many countries. Always follow the instructions and warnings on the product label.
More guides in «How to use».