Mastering the Spray: The Professional’s Guide to Using Aerosols
Whether you are touching up a painted surface with Rust-Oleum, applying a Tygris lubricant, or using a specialist paint primer, the humble aerosol is one of the most versatile tools in your kit. However, getting a flawless, "factory" finish requires more than just pointing and spraying.
Below, we’ve put together the essential steps to ensure you get the best performance out of every can.
1. Temperature is Everything
As we’ve discussed, aerosols are sensitive to the cold. If a can is too cold, the pressure drops, leading to "spitting" and an uneven finish.
- The Pro Tip: If your cans have been stored in a cold van or garage, place them in a container of hand-hot (lukewarm) water for about 10-20 minutes before use. This thins the product and increases internal pressure for a finer mist.
- Safety Warning: Never use boiling water or place a can on a radiator. If the temperature exceeds 50°C, the can becomes a safety hazard.
2. The Two-Minute Rule
It’s the step everyone wants to skip: shaking the can. Most aerosols contain a small mixing ball (the "pea"). You should shake the can vigorously for at least two full minutes after the mixing ball starts to rattle. This ensures the pigment and propellant are perfectly blended, preventing colour mismatches or nozzle clogs.
3. Preparation of the Surface
An aerosol is only as good as the surface it’s sticking to.
- Clean: Remove all dust, grease, and moisture.
- Sand: For paints, a light sand with a fine abrasive creates a "key" for the paint to grip.
- Prime: If you are spraying bare metal or plastic, always use the appropriate primer to prevent peeling later.
4. The Perfect Spray Technique
The biggest mistake is trying to cover the surface in one thick coat. This almost always leads to "runs" and "sags."
- Test Spray: Always fire a quick burst onto a piece of scrap cardboard first to clear the nozzle and check the spray pattern.
- Thin Coats: Apply several thin, light coats rather than one heavy one.
- The "Pass" Method: Start your spray before you reach the object and stop after you have passed it. Keep the can roughly 20–30cm away and move in steady, overlapping horizontal passes.
5. Aftercare: Prevent Blocked Nozzles
There is nothing more frustrating than finding a half-full can with a blocked nozzle the next time you need it.
- The Upside-Down Trick: When you’ve finished your task, turn the can upside down and spray for a couple of seconds until only clear gas comes out. This clears the "dip tube" and nozzle of any remaining product, ensuring it's ready for its next use.
Conclusion
Taking an extra few minutes to warm, shake, and prep will save you hours of sanding back mistakes. By following these simple trade tips, you’ll achieve a durable, professional finish every time.
