How to Retrobright Yellowed Kiosk Plastic
Gray and white kiosk plastic from the 90s and 2000s turns yellow as it ages. Retrobright is the method collectors use to bring it back. It works, but it is not risk free, and on a kiosk you are often working on large, hard to replace panels. Here is what to know before you start.
Why kiosk plastic yellows
Most console and kiosk plastic is ABS. Years of store lighting, sunlight and heat cause photo oxidation, which turns the surface yellow. Kiosks had it worse than home consoles, sitting under fluorescent tubes 12 hours a day.
How Retrobright works
Retrobright uses hydrogen peroxide plus UV light to bleach the yellow out of ABS. The modern method came together in 2008, when collectors refined a peroxide formula and found UV exposure was the key ingredient.
- Cream method. Many collectors use salon hair developer cream with about 9 to 12 percent hydrogen peroxide. It clings to large vertical panels, which makes it popular for kiosk parts.
- Liquid soak. Small parts can be submerged in peroxide solution and placed in sun or under a UV lamp.
- Sunlight only. Some collectors skip the chemicals and simply leave parts in bright sun, checking often.
Step by step
- Remove every decal, sticker, printed label and metal part you can. Peroxide can fade printing and attack adhesives.
- Wash the plastic with warm soapy water and let it dry.
- Wear gloves and eye protection. Salon strength peroxide irritates skin and eyes.
- Apply an even coat of cream, then wrap the part in clear plastic wrap so it doesn't dry out.
- Put it in sun or under UV light. Check every hour or so and rotate the part.
- Once the color evens out, rinse thoroughly and let it dry.
The risks
Retrobright can leave streaks and blotches, especially where cream dries unevenly. Research on treated plastic has also found the yellow can come back, and the process may weaken plastic that is already brittle. On a rare kiosk part, test a hidden area first, and think about whether a slightly yellow original is worth the risk.
What not to Retrobright
- Printed signage and headers. The printing can fade or lift.
- Clear acrylic covers. They don't yellow the same way and can craze.
- Painted or chromed parts.
Related kiosks
Sources: Wikipedia, Retrobright, RetroTechCollection, Retrobrite