How to Prepare Plastic Bumpers for Paint

How to avoid flaking paint on Plastic

Since the 1970’s a lot of vehicles started using a lot of plastic in their construction and the use has only grown over the years to the point where a good portion of a vehicle is made up of plastic. When you need to repair or repaint the plastic it can be difficult to get the paint to stick, shine, and ultimately last. We’ve put together some tips for preparing plastic for a paint job and some ways you can assure you get a lasting paint job.

  1. Clean, Clean Again, Clean some more- Plastic can be deceiving on when it is clean. Even though it may appear to be smooth to the touch it may hold some dirt and contaminants that can hurt the longevity of the paint job. We like to start with a mild soap and water bath to take over an major dirt, grease, or road grime. From there you can use a paint prep like acetone or a PRE Low VOC Paint Prep. Give extra time to let these flash off the surface before painting. You can then use a tack rag take any mild dust or dirt off the surface just before spraying.
  2. Use an Adhesion Promoter- Because plastic isn’t porous like other materials it doesn’t always leave the best surface for the paint to bite into. If you abrade the surface some you can definitely help the cause but you don’t wan to go to aggressive with sandpaper grits as it will show through your paint. We like to use an adhesion promoter before paint to help avoid paint chipping or peeling over time on plastic parts. It is also advisable to apply coatings like primer and paints in a wet on wet fashion to help promote the interlinking of the coatings and keep them from delaminating.
  3. Start with Dust/Tack Coats- Running paint on a surface can be very frustrating and we commonly see it happen on plastic so we like to apply our first coat or two lighter than the proceeding coats. Use these coats as “tack coats” to get some material on the surface but you might not fully cover the project in the color. Once the paint has flashed off you can apply your additional coats laying them on a little heavier. The tack coat will help “grab” onto the paint and as long as you aren’t too heavy handed you won’t be as likely to run the paint. Make sure you check your paint requirements for flash/tack time and wet on wet application.

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