De-yellowing results

Chuck Guzis cclist at
Mon Aug 31 13:43:01 CDT 2015

On 08/30/2015 05:55 PM, Tothwolf wrote:

> Wrong type of UV. You are mostly getting long wave UVA outdoors, so
> blacklight lamps would seem to be the correct (and MUCH safer)
> choice. When I looked at 24" T8 bi-pin blacklight lamps, they were
> going for about USD $10 per lamp.
> UVC germicidal lamps would also require an enclosure to protect the
> user from exposure to short wave UV. This isn't as necessary with
> long wave UVA (unless someone was going to be around it for long
> periods of time on a regular basis).

Some digging for anectodal evidence (there's very little methodical 
technical stuff) on the process indicates that the ordinary 
aquarium-style UVA lamps work extremely slowly; the germicidal UVC lamps 
work very quickly, but overexposure to UVC is counter-productive in that 
it furthers the breakdown of the flame retardant bromine-containing 
stuff that caused the yellowing.  So perhaps UVB is the best compromise, 
assuming that Planck was onto something...

Note that much of the material on the web does not concern computer 

The most disturbing reports were from the people to de-yellowed 
gloss-finish items reporting that said items come out less than glossy, 
particularly when percarbonate (Oxiclean) was added to the mix.

Reports were varied and interesting.   UV was cited repeatedly as a 
suspect when it came to causing yellowing in the first place  This flies 
in the face of my experience in that I've had gear that's spent almost 
all of its life in a closed storage cabinet that yellowed anyway.

Regardless of all of this, it seems that yellowing does recur, which is 
what one would expect from what amounts to a surface treatment.

No, I don't plan on using this process...


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