Rejuvenate Your Vehicles Stained Or Discolored Interior Plastic
What Causes Plastic To Be Stained And Discolored?
A vehicle's interior plastic can be made up of the following materials: acrylonitrile-butadiene-styrene (ABS), ABS/polycarbonate alloys, polycarbonates, polypropylene, SMA (styrene-maleic anhydride) resins, modified polyphenylene ether (PPE). When UV light makes contact with the plastic for long periods of time it eventually pulls the chemicals in the plastic to the surface causing a white/yellow look. Plastic can also be stained by a spilled soda or coffee if not cleaned for several days.
Can Oxidized Plastic Be Restored?
The short answer is yes. There are a few ways to restore plastic to it's original color. The first way which is popular is by cleaning the part and painting it with 40% peroxide, then saran wrap it with clear plastic and place it in the sun. The UV light interacts with the peroxide causing the hydrogen in the peroxide to bond with the plastic chemicals reverting it back to the original color. This solution I find doesn't last quite as long and eventually starts to whiten/yellow again. The next way is to use a plastic polishing compound that can rejuvenate the plastic, again I believe this is to be a temporary fix and doesn't last as long as my solution. The method I use consists of sandpaper and a propane torch.
With the prices of interior plastic it can get very costly. Another popular reason would be, with older collectible vehicles most people can't find the automotive replacement parts anymore at that point it boils down to it's either deal with a not so good looking accessory, or rejuvenate it yourself. Keep reading, I think you'll be pleasantly surprised with the outcome!
Why Not Just Buy New Interior Plastic?
Prepping The Interior Plastic
The first step is to clean the plastic thoroughly. You can use rubbing alcohol or any household cleaner. I chose to use Purple Power and then washed the parts off with a hose until they felt grippy. Now you're ready for the rejuvenation process.
Remove All Accessories From Plastic
Once you're done prepping the interior plastic be sure to remove all of the screws and accessories from the plastic. You will be rejuvenating them individually. *NOTE: Remove all electrical components before "Prepping The Interior Plastic".
Sanding The Stained Or Oxidized Plastic
Now that your parts are all clean you will want to use 220 grit sandpaper. You can use 120 grit to start with if the oxidation or stain is really deep, but it's best to use a finer grit paper as it will be less work to remove the deep scratches later. Spray the part and sandpaper with water, you're going to be wet sanding the plastic. Continue to sand until you are satisfied with the color of the plastic. I used this special tool to sand. Depending on how deep the oxidation or stain is, this method will remove the texture in the plastic to a smoother finish. If you prefer to keep the texture then use the peroxide method. Unfortunately most plastics are either stained too deep or oxidized to deep and need the wet sanding method.
Cleaning The Plastic
Now that you've finished sanding and you're happy with the color, it's time to clean again thoroughly. Make sure that these parts are extremely clean. I sprayed the parts down with Purple Power and then rinse them off with a hose until they felt grippy. When you're done cleaning them, dry them off. It's important that you make sure there's no water left on the part for the next step.
Making The Plastic Shine Again
Now I'm sure you're looking at the plastic thinking, it's a white haze and ruined! No worries, I'm about to explain to you how to make the plastic like new again with very little effort. You are going to need a propane torch, go ahead and light the propane torch and aim the flame at the plastic. *Note: This is why I mentioned you need to remove "all" the water, if the heat from the torch hits the water it will sizzle and make an imperfection in the plastic. *Keep in mind you want to keep the flame moving and not hold it in one spot too long or else you will melt a hole in the plastic. Play around with the torch by going fast and you will start to see the plastic change to it's original luster. Once you get comfortable you'll be able to slow down the pace and really bring out the vibrant color.