Spray painting is a popular DIY project for both indoor and outdoor surfaces. However, cold temperatures can significantly impact the process and outcome of spray painting. Proper preparation and technique adjustments are necessary when spray painting in cold weather to achieve quality results. This comprehensive guide covers everything you need to know about spray painting when temperatures drop.
Key Takeaways on Spray Painting in Cold Weather
- Temperatures below 50°F can negatively impact spray paint application and performance.
- Properly preparing paint and surfaces is crucial for good results when spray painting in marginal temperatures.
- Adjust techniques like shaking the can well, applying lighter coats, and holding the can closer.
- Extend drying times significantly, and bring painted items indoors to cure and harden fully after application.
- Specialty spray paints designed for cold weather offer improved flow and drying characteristics.
- With careful precautions, spray painting can still produce quality finishes even when temperatures are less than ideal.
How Cold is Too Cold for Spray Paint?
In general, temperatures below 50°F are considered too cold for ideal spray paint application. However, some specialty spray paints are formulated for use in temperatures as low as 35°F.
Spray painting when it’s colder than 50°F can negatively impact the paint in several ways:
- Poor paint atomization – The paint may sputter out of the can in large droplets rather than a fine mist. This can cause an uneven finish.
- Reduced paint flow – Cold paint has a thicker consistency and doesn’t flow as smoothly onto surfaces. This can lead to brush strokes, thin coverage, and dripping.
- Longer drying times – Solvents evaporate more slowly in cold temperatures, extending the drying time of spray paint.
- Impaired adhesion – Cold surfaces don’t allow the paint to properly penetrate and bond. Freshly painted finishes may peel or chip.
- Increased risk of runs and sags – Heavy coats of paint are more likely to drip and run when applied in the cold.
- Shortened pot life – Two-component paints like epoxies and urethanes have less working time when applied in lower temperatures.
For best results, wait for warmer weather if temperatures will be dropping below 50°F. If you must paint in marginal conditions, take steps to warm paint and surfaces to improve application.
Is It Okay to Spray Paint in Cold Weather?
Spray painting when temperatures fall below 50°F is possible, but it presents challenges. With proper preparation and careful technique, you can achieve adequate results spray painting in colder weather.
While not ideal, some situations may necessitate cold weather painting, such as:
- Urgent need to refinish outdoor furniture before winter
- Touching up paint on a car kept outside
- Seasonal demand for painted crafts or decorations
- Painting rented equipment on a tight timeline
As long as you understand the limitations and risks of applying spray paint in the cold, go ahead with proper precautions in place. Test spray painted items after drying for proper adhesion and durability.
Cold Weather Spray Painting Tips
Follow these tips when spray painting in cold temperatures to get the best possible results:
Use Cold Temperature Spray Paint
Choose paint specifically designed for low temps. Look for words like “cold galvanizing,” “winter,” or temperature ranges on the label. The formula will include additives to enhance flow and drying time.
Warm the Paint Can
Before painting, place spray cans in warm water for 15-20 minutes. This helps the paint thin out for better misting and flow. Aim for paint temp of 65-70°F.
Shake the Can Vigorously
Shake the can for at least 5 minutes to thoroughly mix the pigment and suspension agents. The ball in the can should rattle the entire time while shaking.
Apply Light Coats
Use thin, even layers instead of heavy coats which are prone to sagging and dripping in cold conditions. Let each light coat dry completely between applications.
Allow for Longer Dry Times
Drying takes much longer in the cold. Allow 2-3 times longer than the label recommends between coats. Test thickness frequently by gently touching painted areas.
Warm the Surface
For metal, plastic, or wood, gently warm the surface with a heat gun or hairdryer before and after paint application. This aids paint adhesion and drying. Don’t overheat.
Cure Indoors
Once fully dry, bring painted items into a warm space to cure and harden thoroughly before use. Ideal curing temps are 65-75°F.
Add Clear Coat (Optional)
Applying a clear top coat like polyurethane over spray paint creates an extra barrier against damage like chipping and abrasions. Allow paint to cure fully before adding a protective clear layer.
Is It Bad to Leave Spray Paint Cans in the Cold?
Leaving spray paint cans outdoors in freezing temperatures for extended periods can negatively impact the paint:
- Freezing – Paint can freeze inside the can, becoming unusable. Always store spray paint above 40°F.
- Component separation – Cold causes binders, pigments, solvents and propellants to separate. Vigorous shaking is required to remix.
- Loss of pressure – Propellant condenses in extreme cold. Affected cans may not spray properly.
- Thickened paint – Paint thickens and clumps when stored below recommended temps. Flow and atomization will suffer.
For best quality results, bring spray paint indoors and allow cans to reach room temperature before use. If left in cold vehicles or unheated spaces, warm paint cans prior to application.
Can You Spray Paint Metal in Cold Temperatures?
Metal can be spray painted in cold weather, but extra care is required. Follow these tips when spray painting metal when it’s cold outside:
- Clean and sand – Remove any dirt, oil, rust, or old paint so the new paint can adhere properly. Sand glossy surfaces.
- Warm the metal – Heat metal with a hairdryer or heat gun before and after painting. Avoid overheating.
- Use a primer – Primer helps the topcoat stick to the bare metal surface. Apply primer before painting the metal.
- Adjust technique – Keep the spray can close to the surface and apply thin coats to prevent drips and runs.
- Allow longer dry time – It can take up to 2 hours for each coat to dry thoroughly on metal in cold weather.
- Cure indoors – Once fully dry, transfer the metal object to a warm indoor space for proper curing.
With careful surface prep and adjusted technique, metal spray painting in the cold can produce durable, quality results. Enamel and lacquer paints formulated for metal work best.
How Does Temperature Affect Spray Paint?
Outside of the ideal range, temperature has various effects on spray paint application and the resulting finish:
Warmer temperatures (above 90°F):
- Fast drying – Paint dries too quickly and can clog the spray tip.
- Poor adhesion – Paint won’t bond well to hot surfaces.
- Bubbling – Solvents evaporate rapidly, forming bubbles under the paint.
- Blushing – Moisture gets trapped, leaving a hazy finish.
Colder temperatures (below 50°F):
- Poor atomization – Paint spews out in uneven droplets rather than a fine mist.
- Orange peel effect – Paint dries too quickly, creating a rough texture.
- Runs and sags – Thicker paint is more likely to drip and slide down the surface.
- Longer drying – Paint takes much longer to dry and cure.
- Chipping/peeling – Cold surfaces prevent good adhesion.
For best results, spray paint when ambient air and surface temperatures are between 50-90°F. Avoid extreme temps.
How to Dry Spray Paint Faster in Cold Weather
To reduce drying time for spray paint in cold conditions, try these tricks:
- Move item to a warm space – Let painted object dry indoors at room temperature if possible.
- Use a portable heater – Position a space heater or heat lamp nearby to warm the air and surface.
- Apply heat directly – Use a blow dryer, heat gun, or halogen work light on low setting to gently warm the paint. Avoid overheating.
- Add a drying accelerator – Special spray paint additives speed drying chemical reactions. Follow directions carefully.
- Use quicker-drying paint – Lacquers and enamels formulated for cold weather include fast-evaporating solvents.
- Apply thinner coats – Light mist coats dry faster than heavy wet coats. Build up the finish with multiple thin layers.
- Increase air circulation – Set up fans to move air across the surface, whisking away solvents for faster drying.
With patience and a few of these tricks, spray painted items can fully dry within a reasonable timeframe even when temperatures are below 50°F.
How to Prevent Runs and Sags When Spray Painting in Cold Weather
Heavy, wet coats of spray paint are prone to dripping and running down vertical surfaces in cold conditions before they have a chance to dry. To prevent runs and sags when spray painting in low temperatures:
- Shake the can vigorously before use – This mixes the paint thoroughly so it sprays out smoothly.
- Keep the can moving – Maintain a steady back and forth motion and don’t pause in one spot too long.
- Work quickly over small areas – Paint sections in light coats then move onto the next area before returning.
- Hold can 6-8 inches from surface – Optimal spray distance is closer when it’s cold. This allows paint to atomize properly.
Cold Weather Precautions for Different Paint Types
Certain kinds of spray paint require extra precautions when applying in cold conditions:
Acrylic Paint
- Acrylics become thicker and dry slowly in the cold.
- Use an indoor space heater to maintain indoor temperature above 50°F.
- Allow even more time between coats – up to 4 hours.
- Do not apply if temps may dip below freezing before paint has fully dried.
Automotive Paint
- Keep spray cans in a warmer area to prevent loss of pressure.
- Use maximum diluent levels to get proper atomization.
- Allow coated car parts to flash off and dry indoors before assembling.
Enamel Paint
- Enamels formulated for metals contain anti-corrosion additives that slow drying time in the cold.
- Use a primer on metal before applying enamel topcoats.
- Cure painted metal objects indoors for 24-48 hours.
Krylon Fusion Paint
- Krylon Fusion bonds best between 50-90°F.
- Use light coats close to the surface to prevent drips and sags.
- Allow each coat to dry indoors for 2-3 hours before recoating or touching.
Rustoleum Paint
- Rustoleum requires 65°F for proper curing. Use indoors if possible.
- Shake the can for 5 minutes vigorously before spraying.
- Recoat within 1 hour between light mists.
Tips for Spray Painting Plastics in Cold Weather
Paint adheres best to clean, dry surfaces. Prepare plastic for cold weather spray painting by:
- Washing with soap and water to remove any dirt and oils
- Sanding lightly with fine grit sandpaper to help paint bite into slick plastic
- Wiping down with tack cloth to remove dust
Use plastic-specific spray paint like Krylon Fusion or Rustoleum Plastic. Apply light coats about 8 inches from the surface to prevent drips. Allow each coat to dry completely indoors – up to 2 hours per coat.
For plastics prone to cracking like polystyrene foam, add a clear acrylic sealer layer. This helps prevent paint from splitting if the plastic flexes.
Troubleshooting Cold Weather Spray Paint Problems
Problem: Paint not spraying out of can
Solution: Bring spray paint indoors to warm up. Shake can vigorously for 5 minutes. Remove nozzle to check for clogs.
Problem: Paint dripping or running down the surface
Solution: Apply lighter coats closer to the surface. Allow proper drying time between coats. Warm paint and surface to optimal temperature.
Problem: Finish is rough and uneven
Solution: Shake can well to mix pigment, spray from proper distance, and use smooth strokes. Add additional light coats.
Problem: Paint peeling or chipping
Solution: Warm surface before painting, allow extra drying time, and cure indoors. Use primer on metal and plastics.
Problem: Paint not fully drying
Solution: Move item indoors or use supplemental heat. Allow much longer dry times between coats.
