Retrobright

One method of reversing the yellowed discoloration was first discovered in 2007 in a German retrocomputing forum,{{cite web|url=https://www.forum64.de/index.php?thread/14918-restaurierung-eines-c-64g-oder-das-gastgeschenk-des-doc64/&postID=139741#post139741|title=Forum64 — Restaurierung eines C-64G, oder das Gastgeschenk des DOC64|date=February 19, 2007|access-date=August 21, 2018|archive-date=August 20, 2018|archive-url=https://web.archive.org/web/20180820235132/https://www.forum64.de/index.php?thread%2F14918-restaurierung-eines-c-64g-oder-das-gastgeschenk-des-doc64%2F&postID=139741#post139741|url-status=live}} before spreading to an English blog where it was further detailed.{{cite web|url=http://retr0bright.wikispaces.com:80/|title=The "Retr0bright" Project|date=July 28, 2010|access-date=August 21, 2018|archive-url=https://web.archive.org/web/20100904035139/http://retr0bright.wikispaces.com/|archive-date=September 4, 2010|url-status=live}}{{cite web|url=http://www.boingboing.net/2009/03/02/open-source-computer.html|title=Open source computer polish: Retr0Brite|website=Boing Boing|first=Cory|last=Doctorow|date=March 2, 2009|access-date=September 21, 2017|archive-date=September 21, 2017|archive-url=https://web.archive.org/web/20170921193443/https://boingboing.net/2009/03/02/open-source-computer.html|url-status=live}}{{cite web|url=https://www.tomsguide.com/us/retr0bright-hardware-restoration,news-7595.html|title=How To Restore Your Beige Retro Hardware|website=Tom's Guide|publisher=Tom's Hardware|date=July 28, 2010|first=Rico|last=Mossesgeld|access-date=September 21, 2017|archive-date=August 20, 2018|archive-url=https://web.archive.org/web/20180820234953/https://www.tomsguide.com/us/retr0bright-hardware-restoration,news-7595.html|url-status=live}} The process has been continually refined since.

Retrobright consists of hydrogen peroxide, a small amount of the "active oxygen" laundry booster TAED as a catalyst, and a source of UV.{{cite web|url=https://makezine.com/2009/03/02/unyellow-old-plastics-retr0brite/|title=Un-Yellow Old Plastics – Retr0brite!|first=John|last=Maushammer|date=March 2, 2009|access-date=September 21, 2017|magazine=Make:|archive-date=September 21, 2017|archive-url=https://web.archive.org/web/20170921194125/https://makezine.com/2009/03/02/unyellow-old-plastics-retr0brite/|url-status=live}}

The optimum mixture and conditions for reversing yellowing of plastics:

• A hydrogen peroxide solution.{{Cite web |url=https://www.youtube.com/watch?v=qZYbchvSUDY |title=Adventures in Retrobrite - New techniques for restoring yellowed plastic! |last=Murray |first=David |website=YouTube |date=20 August 2017 |series=The 8-Bit Guy |accessdate=26 November 2019 |archive-date=1 December 2019 |archive-url=https://web.archive.org/web/20191201193121/https://www.youtube.com/watch?v=qZYbchvSUDY |url-status=live }}{{Unreliable source?|date=April 2024}} Hydrogen peroxide-based hair bleaching creams available at beauty supply stores can also be used, and are viscous, allowing them to be applied with less waste (especially to large pieces such as computer panels or monitors).{{cite web|url=https://kotaku.com/super-strong-hair-product-is-the-secret-to-get-old-cons-1638537069|title=The Secret To Keeping Old Consoles Looking New? Hair Product.|first=Evan|last=Narcisse|date=September 24, 2014|website=Kotaku|access-date=September 21, 2017|archive-date=May 15, 2017|archive-url=https://web.archive.org/web/20170515184040/http://kotaku.com/super-strong-hair-product-is-the-secret-to-get-old-cons-1638537069|url-status=live}}{{Cite AV media|series=The 8-Bit Guy|first=David|last=Murray|title=How to fix yellowed plastics on old computers!|date=April 6, 2013|url=https://www.youtube.com/watch?v=VU7vXMezW_I |archive-url=https://ghostarchive.org/varchive/youtube/20211215/VU7vXMezW_I |archive-date=2021-12-15 |url-status=live|accessdate=May 29, 2017}}{{cbignore}}{{Unreliable source?|date=April 2024}} The cream must be carefully applied and wrapped evenly with plastic wrap to avoid streaks in the final product.{{Cite news|url=https://www.thegeekpub.com/13216/how-retrobright-works/|title=How Retrobright Works! - The Geek Pub|date=May 27, 2018|work=The Geek Pub|access-date=May 27, 2018|language=en-US|archive-date=May 28, 2018|archive-url=https://web.archive.org/web/20180528133352/https://www.thegeekpub.com/13216/how-retrobright-works/|url-status=live}}
• Approximately 1 ml per 3 liters (1 part in 3000 by volume, alternatively {{frac|1|4}} teaspoonful per US gallon) of tetraacetylethylenediamine (TAED)-based laundry booster (concentrations of TAED vary).
• A source of ultraviolet light, from sunlight or a UV lamp.

Xanthan gum or arrowroot can be added to the solution, creating an easier-to-apply gel.{{Citation needed|date=November 2023}}

{{More citations needed section|date=April 2024}}

Sodium percarbonate may also be used by dissolving it in water and following the usual steps for hydrogen peroxide, as it is sodium carbonate and hydrogen peroxide in a crystalline form.

Ozone gas can also be used for retrobrighting, as long as an ozone generator, a suitable container of sufficient size and a source of UV are available, but can take longer than other methods.

A simpler but slower process involving merely exposure of the yellowed plastic to bright sunlight has been described, variously called 'Sunbrighting' or 'Lightbrighting'. This has both empirical evidence of effectiveness and the theoretical backing of some [https://forums.atariage.com/topic/291210-new-technique-for-whitening-yellowed-plastic/page/3/#comment-4311251 published scientific literature], which emphasises exposure to strong visible light while minimising ultraviolet exposure.

The long-term effectiveness of these techniques is unclear. Some have discovered the yellowing reappears, and there are concerns that the process weakens and only bleaches the already damaged plastic.{{cite web | url=http://www.classic-computers.org.nz/blog/2013-01-15-retr0bright-only-temporary.htm | first=Terry | last=Stewart | title=Retr0Bright (or RetroBright) treated plastics re-yellowing even with minimal light exposure? | access-date=September 21, 2017 | publication-date=January 15, 2013 | date=January 17, 2013 | archive-date=September 6, 2017 | archive-url=https://web.archive.org/web/20170906143613/http://www.classic-computers.org.nz/blog/2013-01-15-retr0bright-only-temporary.htm | url-status=live }}{{cite web|url=http://aktuelbevaring.natmus.dk/afrensning-af-plast-med-retrobright.html|title=Afrensning af plast med RetrObright|trans-title=Plastic cleaning with RetrObright|language=danish|first=Anja Liss|last=Petersen|date=January 19, 2011|access-date=September 21, 2017|archive-date=April 2, 2015|archive-url=https://web.archive.org/web/20150402143207/http://aktuelbevaring.natmus.dk/afrensning-af-plast-med-retrobright.html|url-status=live}}{{cite web|url=https://medium.com/@pueojit/a-look-into-the-yellowing-and-deyellowing-of-abs-plastics-db14b646e0ad|first=David|last=Flood|title=A Look into the Yellowing and Deyellowing of ABS Plastics|date=April 14, 2018|access-date=September 30, 2021|archive-date=September 30, 2021|archive-url=https://web.archive.org/web/20210930184922/https://medium.com/@pueojit/a-look-into-the-yellowing-and-deyellowing-of-abs-plastics-db14b646e0ad|url-status=live}}

The usage has also expanded to other retro restoration applications, such as classic and collectible sneaker restoration.{{Cite web |title=How to Easily Restore Yellowed Shoes |url=https://angelusdirect.com/blogs/news/how-to-easily-restore-yellowed-shoes |access-date=2023-02-04 |website=Angelus Direct |language=en}}

{{refs}}

{{Portal bar|Chemistry|1980s|1990s}}

Category:Cleaning products

Category:Plastics

Category:Hacker culture