How to Cure Automotive Paint

Urethane auto paint provides a hard durable finish when cured properly.

Curing automotive paint is about the chemical reaction occurring in the paint. If the right conditions are not cultivated, the paint can exhibit a variety of disappointing conditions like crazing, wrinkling and peeling. Acrylic enamel auto paints use a hardening additive and applied heat to speed the curing process. Urethane auto paints require the correct "activator" product that triggers the hardening or curing process to take place. No matter the type of auto paint chosen, the process of painting a car requires careful preparation and a thorough reading of the manufacturer's recommendations.

Things You'll Need

• Paint booth
• Heat lamp
• Urethane or acrylic enamel paint
• Acrylic enamel hardener
• Urethane activator
• Paint spraying equipment

Instructions

1. Read the manufacturer's directions found on the paint's label or accompanying materials. The manufacturer will reveal the time span and curing process their paint system uses. Follow these instructions for best results.

2. Paint the car inside a paint booth or area completely protected from dust, debris and wind. Paint booths provide clean environments that prevent dirt and dust from attaching to the wet paint as it is curing. Paint booths should always be well-ventilated and the air should be filtered to remove debris. Local body shops usually allow hobbyists to rent a paint booth during off hours.

3. Clean the surface of the car or automotive parts using grease and wax removers before beginning the painting process. This removes possible chemical contamination of the auto paint.

4. Add a paint catalyst to the acrylic enamel paint. A paint catalyst also is known as a hardener or drier because it speeds the curing time. The catalyst is added to the paint before it is sprayed onto the car. Hardener's can speed curing times down to minutes and hours instead of days.

5. Add an activator to a urethane paint that is part of the paint system. Using activators from a different manufacturer or brand can alter the results. Paint systems are a group of products designed and tested to work together. Recipes and ingredients vary between manufacturers. Combining brands can cause crazing, wrinkling and peeling of the paint.

6. Place an ultraviolet or infrared heat lamp in the drying area. Warming both acrylic enamel or urethane paint can reduce curing time. Read the equipment and paint manufacturer's recommendations for exact instructions. Temperatures higher than 140 degrees can begin melting plastics, rubber and destroy computer equipment on the vehicle. Factory applied paint is cured successfully in 450-degree heat because paint is applied to the bare frame and not to the finished car.

Tips & Warnings

• Always use products from a paint system and do not mix brands.

• Follow all warnings, precautions and recommendations made by the manufacturer to protect your health and safety and get the best results from the paint.

• Paint and paint products are flammable. Do not spray or use these products where sources of heat or flame are present. Follow the manufacturer's directions for using a heat source in the drying process.

• Clean the surface only after the paint is cured and only use paint manufacturer recommended tools. The use of a scraper, a dry cloth, a stiff brush or other cleaning tools can damage the surface. Do not park the car under trees and do not drive across surfaces like gravel rock that can throw stones and debris at the vehicle. Avoid spilling engine oil, antifreeze, gasoline or other chemicals on the cured paint. These substances can soften and destroy the cured paint. Rinse immediately with water and pat dry.

References

• "Auto Body Repair Technology"; James E. Duffy, Robert Scharff; 2003
• "How To Build A Killer Street Machine"; Jefferson Bryant; 2010
• "How To Paint Your Car"; Dennis W. Parks, David H. Jacobs; 2003