Back to basics: Hybrid refinishing and baking 

Sometimes, going back-to-basics can make the difference between a quality repair and a failed repair. When repairing and refinishing electric vehicles (EVs), unintentional damage to the battery can be avoided by taking the proper steps including researching the paint maker technical data sheets (TDS) for optimal clearcoat baking requirements and vehicle maker service information for temperature and time restrictions. 

Each paint maker has different recommendations for optimal clearcoat baking applications. Provided in the paint maker TDS are temperature and time ranges. These ranges may be based on booth air temperature or substrate temperature. As a result, this leaves some questions up in the air, such as:  

• How do you determine which temperature measuring method to use?  
• How could the baking operation affect your repair? 
• What other resources are available? 

When reviewing a paint maker TDS, you may find statements determining how force dry temperatures are measured. Here are a few examples from product-specific TDS: 

AkzoNobel: 

• “Drying times are stated at recommended application method, film thickness, and object temperature. Drying temperatures provided are for metal or object temperature.” 
• “Drying times are stated at recommended application method, film thickness, and ambient temperature. The dry times stated may increase with insufficient airflow.” 

Axalta: 

• “10-15 minutes x 71°C booth temp” 
• “Drying time at 60°C metal temp 20 to 30 minutes” 
• “Bake 30 min for 60°C panel temperature” 

BASF: 

• In product specific TDS, temperatures and time ranges are stated, but how to measure the temperature is not disclosed. We reached out for clarification. Per the BASF Techline (hotline), BASF uses metal temperatures to measure force dry times. 

PPG: 

• “All force dry times are quoted for metal temperature. Additional time must be allowed during force drying to allow metal to reach the recommended temperature.” 

Sherwin-Williams: 

• “Do not exceed 65°C surface temperature while baking. Do not exceed 20 minutes total baking time.” 
• “Bake 10 minutes at 49°C surface temperature.” 

Each paint maker has different verbiage to state how to measure recommended bake temperatures and times. Different mixing ratios, solvent selection, or additives can change bake recommendations. Be aware some products do not recommend force drying, this can be found in some air dry or speed clear coats. 

How could product selection change the repair process for EVs? When researching repair procedures take note of vehicle maker warnings relating to EV battery temperatures. We have gathered these precautions as part of the OEM Hybrid and Electric Vehicle Disable Search. A simple search can provide vehicle maker, vehicle-specific refinish precaution statements along with additional information. 

A vehicle maker might recommend a temperature and time not to exceed when baking refinish products to prevent battery damage. The vehicle being repaired may require alternative paint shop scheduling or clearcoat product selection. A shop might prefer to select a different product or mixture which accommodates air drying and having the car refinished at the end of the day to allow enough time for air drying. 

Where to look to find more information related to paint maker recommendations or vehicle maker paint precautions? Paint makers offer technical resources including TDS libraries online or built into their color retrieval software, regional technical representatives and easy to use technical hotlines. Lastly, do not forget to reference vehicle maker repair manuals to confirm refinishing precautions and other precautions pertaining to the repair. 

Keen to know more about the ins and outs of hybrid and EV refinishing and baking? I-CAR Canada can help. I-CAR Canada provides a comprehensive catalogue of continued collision training programs, including refinish technician courses. Sign up for I-CAR Canada courses to cement your knowledge of hybrid vehicle refinishing and baking.  

About I-CAR Canada 

I-CAR is an international organization dedicated to providing the information required to perform complete, safe, and quality auto repairs.  

I-CAR Canada is a training and recognition program run by the Automotive Industries Association of Canada (AIA Canada), a not-for-profit organization representing, supporting and leading innovation in Canada’s $37.8 billion auto care sector. 

Aimed at up-skilling tradespeople in the collision industry, I-CAR training has been available in Canada since 1979 and has been operated by AIA Canada since 2010.