Despite being durable, black plastics (especially on vehicle bumpers and trim) have a tendency to dull and discolor over time. Fortunately, you can easily restore the natural shine of plastic. You can make the plastic look like new by applying a coat of olive oil or using a heat gun on the dull areas. If that doesn't work, you can use a black paint spray to get the plastic back to a shiny shine.
Method 1 of 3: Apply Oil to Opaque Plastic
Step 1. Wash and dry the surface of the plastic
A clean surface will absorb the olive oil better. If the plastic object is dirty, wash it with soap and warm water. Then dry it with a towel before applying the oil, as it slides on a wet surface.
Step 2. Pour a small amount of olive oil, about the size of a coin, onto a cloth
Olive oil can restore the natural color of plastic and lighten dull and discolored areas. Pour a small amount of olive oil, about the size of a quarter, onto a cloth or paper towel. A little oil is enough for a large area, plus you can pour a little more according to need.
Baby oil and flaxseed oil also work and are a good alternative
Step 3. Rub the olive oil over the plastic
Wipe the cloth or paper towel back and forth over the work area. Continue scrubbing the area for several minutes until the plastic absorbs the olive oil.
To prevent olive oil from staining adjacent items, cover them with a tarp or towel
Step 4. Buff the plastic with a dry cloth
After you've rubbed the olive oil on the plastic for a few minutes, take a dry cloth and buff the plastic in circular motions. Use plenty of pressure as you do this to remove excess olive oil and give the plastic an added shine.
If you don't have another cloth, use the ungreased part of the old paper towel or cloth
Step 5. Check the plastic to see if there are still any discolored areas
When you have removed the olive oil, check the color of the plastic objects to find any unrepaired damage. If you notice any areas that the olive oil has not restored, try going through the process again with more oil directly on this area.
If the condition of the item is too dull or discolored, you may need to use a black paint spray
Step 6. Try a wetting product for plastic trim
Like olive oil, black plastic moisturizing products restore car bumpers and trim with a moisturizing coat. If you prefer to use a product created specifically for cars, you can use most of these in the same way as you would with olive oil.
- You can purchase moisturizing trim products at most auto supply stores. Read the instructions carefully before applying the product on the object.
- If you are trying to restore a black plastic object that is not part of your car, you can use the same product on it.
Method 2 of 3: Using a Hot Air Gun
Step 1. Use a hot air gun as a temporary solution
Heat guns can extract natural oils from plastic and restore its shine, but this is not a long-term solution. The plastic will dull again with use and after several treatments it will no longer have enough natural oils and the hot air gun will not be able to extract them.
- The duration of this method depends on how often the car is exposed to direct sunlight. The more you use the car, the faster the restoration will dull.
- If you've used a heat gun before and the treatment is no longer working, try adding olive oil to the surface of the plastic to restore its shine.
- You can buy or rent a hot air gun online or at some hardware stores.
Step 2. Cover nearby non-plastic objects with a tarp before using the heat gun
Hot air guns can warp or discolor the surfaces of non-plastic objects. If the item you're restoring is attached to something else, cover the areas you don't want to get hot with a heat-resistant tarp.
This method is mainly applied to car moldings and bumpers. Do not use this method on black plastic that is attached to flammable materials (such as some plastic toys)
Step 3. Clean and dry the plastic object
Using a heat gun on dirty plastic can burn residue and stains causing marks. Wash the object with soap and water, clean as much residue as possible and finally dry it with a towel before applying the heat.
Step 4. Hold the hot air gun several inches from the surface
Turn on the hot air gun and move it in small circles around the discolored plastic. Avoid leaving the hot air gun in one place for too long so the color stays even and the plastic doesn't burn.
Do a test with the hot air gun on an inconspicuous place to ensure that the color treatment of the plastic is satisfactory to you
Step 5. Turn off the hot air gun and check the new color of the plastic
As you move the hot air gun around the plastic it should change to a darker, more vivid color. When you've covered the entire surface, turn off the heat gun and check the plastic. If you are satisfied with the new color, you have finished restoring the item.
If the plastic still looks dull and discolored, try applying olive oil or paint to the object
Method 3 of 3: Paint the Plastic Black
Step 1. Wash the plastic item with soap and water
Paint will adhere better to a smooth, dust-free surface. Dip a cloth in warm soapy water and wipe all dust and debris from the surface of the plastic.
- For a deeper cleaning or to remove the toughest society, submerge the item in the water.
- Dry the object with a cloth before painting it.
Step 2. Sand the surface with 220-grit sandpaper
Sanding provides a suitable texture for the paint to adhere. Rub the high-grit sandpaper by applying pressure to the surface of the plastic. When you have finished sanding, clean all the dust with a dry brush.
If you don't have a dry brush, you can use a painter's brush as an alternative
Step 3. Apply a coat of primer to help paint adhesion
Spray a coat of paint primer on the surface of the object. Avoid spraying the area too long to keep the coat even and thin. Let the primer dry for the recommended time on the container, which should be between 30 to 60 minutes.
- You can buy a plastic primer online or at most craft supply stores.
- A thin coat of primer is ideal because when the coat is very thick or multiple coats are applied the texture of the object can change.
Step 4. Spray a coat of black paint on the plastic
Hold the nozzle of the paint can about 12 to 18 inches (30 to 45 cm) from the surface and gently move it over the object. Keep spraying the paint, passing it over and over until the entire surface is covered.
- Apply three to four coats to reinforce the paint color. Wait for the paint to dry between coats.
- Each coat should take about 30-60 minutes to dry. Check the paint container for the specific time.
Step 5. Protect the new paint with a clear primer
After the last coat of paint has dried, spray a clear paint primer over the entire surface. This will prevent the paint from dulling, fading, or cracking over time.
The paint primer is especially important if you are going to use the object outdoors where it will be exposed to the elements
- If you're working with broken or damaged plastic, repair it with glue, acetone, or a soldering iron before restoring color.
- Take the black plastic to a recycling center if its color can no longer be restored to the extent necessary.