Document ID: TOS-PRES-REF-001 Revision: 1.0 Author: ThisOldScot
Section_1: Overview#
Retrobrighting is a chemical process used to reverse the yellowing of ABS (Acrylonitrile Butadiene Styrene) plastics common in vintage consoles like the SNES, NES, and PC Engine. This yellowing is caused by the “blooming” of bromine flame retardants when exposed to UV light. The process uses high-concentration Hydrogen Peroxide ($H_2O_2$) and a UV light source to facilitate an oxidation-reduction reaction that restores the plastic to its original factory color.
This manual outlines the Highlands Lab “Vapor” Method, designed to minimize the risk of “marbling” or “streaking.”
Section_2: Tools & Materials Required#
| Item | Spec | Purpose |
|---|---|---|
| Hydrogen Peroxide | 6% – 12% Cream (Vol 20/40) | The active whitening agent. |
| UV Light Source | 365nm – 395nm LED | Catalyst for the chemical reaction. |
| Clear Plastic Wrap | Standard Kitchen Grade | Preventing the peroxide from drying out. |
| Gloves & Goggles | Nitrile / Polycarbonate | Mandatory chemical safety. |
| Soft Brush | 1-inch Synthetic | Even application of the peroxide cream. |
Section_3: The Restoration Protocol#
STAGE_3: 01 // Deep Cleaning#
Before chemical treatment, the shell must be stripped of all metal components, stickers, and rubber feet.
- Scrub the shell with warm soapy water to remove skin oils and tobacco residue.
- The Logic: Oils create a barrier that prevents the $H_2O_2$ from penetrating the plastic evenly, leading to permanent blotchiness.
STAGE_3: 02 // Application (Cream Method)#
- Wear protective gear. $H_2O_2$ at 12% will cause immediate white chemical burns on skin.
- Apply a thin, uniform layer of the peroxide cream over the entire surface of the plastic.
- Wrap the component tightly in Clear Plastic Wrap. Ensure there are no air bubbles trapped against the surface.
STAGE_3: 03 // UV Exposure#
- Place the wrapped component under UV lights or in direct sunlight.
- Duration: Typically 4 to 8 hours depending on the severity of the yellowing and UV intensity.
- Rotation: Rotate the part every hour to ensure uniform light coverage on all 3D surfaces.
STAGE_3: 04 // Neutralization & Rinse#
- Remove the wrap and rinse the shell under cool running water.
- Use a soft brush to ensure all peroxide residue is removed from textures and screw holes.
- Dry thoroughly before reassembling.
Section_4: Technical Warning#
Safety_Warning
“MARBLING” RISK: Marbling (white streaks) is a permanent structural change in the plastic caused by the peroxide drying out or becoming too hot during the reaction. If you notice the cream beginning to “foam” or bubble excessively under the plastic wrap, the reaction is too aggressive. Move the UV source further away or decrease the exposure time.
Section_5: Practical Application: The SNES Two-Tone#
On many Super Nintendo units, only the bottom shell or the cartridge flaps yellow, while the top remains grey.
- Protocol: Only treat the affected pieces. Retrobrighting “fresh” grey plastic can cause it to become overly light or brittle.
- Longevity: Retrobrighting is not permanent. The plastic will eventually yellow again if exposed to UV light. The Highlands Lab recommends applying a UV-Protective Ceramic Coating or a high-end matte clear coat after the process to lock in the results.
Section_6: Maintenance Log Note#
For large batches, the Submersion Method (using liquid 6% $H_2O_2$ in a transparent vat) is preferred over the cream method as it virtually eliminates the risk of marbling. However, this requires significant chemical volume and is only recommended for high-output workshops.