It’s almost impossible to imagine a world without plastic. But a world full of faded lawn furniture, oxidized ATV fenders, and sunbleached barbecue knobs—that’s easy to imagine. When exposed to the elements, all that bright and shiny plastic gets tired looking. The internet abounds with magic fixes, so I hauled out a set of pathetically faded blue plastic chairs and tried a few, including peanut butter (which works on sandwiches, by the way, not plastic).
I smeared some petroleum jelly on a chair, let it sit out in the sun for a few minutes, and then buffed it off with a paper towel. Where oxidation and dirt had left crusty deposits, I lightly scrubbed with an extra-fine plastic scouring pad before wiping the jelly off. I was surprised by how well it reduced the white haze of oxidation.
Science check*: Petroleum jelly may cause cracking.
The internet told me to hold a heat gun close to the surface and move it in a slow sweeping or a tight circular pattern. Keep it moving, or much more than the surface will melt. The internet didn’t tell me that without cleaning the plastic first, dirt fuses right in. The blue came back well, but with a slightly undulating sheen. Do this outdoors; it needs ventilation. It’s also easy to burn yourself or start a fire. There are better methods, in my opinion.
Science check: This works because heat formed the chairs originally.
Linseed oil and mineral spirits
By far, the most effective plastic rejuvenation in my terribly scientific experiment came from a 60-40 blend of boiled linseed oil and low-odour mineral spirits (paint thinner), rubbed on with a rag. After a minute or so, I buffed the solution off with another rag. The results were spectacular: The colour came back, the mix didn’t smell bad, and it was easy to apply and polish. It worked just as well on the textured black exterior trim on my 2001 van and on barbecue knobs.
Science check: In time, linseed oil may yellow lightcoloured plastics.
*We science-checked with Jean-François (J.-F.) Masson, a chemist with the National Research Council.