De-yellowing results

Tothwolf tothwolf at
Sun Aug 30 20:52:00 CDT 2015

On Sun, 30 Aug 2015, Chuck Guzis wrote:
> 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.
> Oh, but there's that aitch-nu thing--I suspect that the UVC lamps would 
> do the job very quickly.  I recall that someone tried the de-yellowing 
> process with UV LEDs and got nowhere fast.  So probably UVB at a 
> minimum.

Maybe...maybe not. I do know from experience that short wave UVC from 
germicidal lamps can photodegrade certain plastics, PVC in particular. UVC 
germicidal lamps can also cause serious eye damage in very short order. 
Even the really small UVC lamps used in an EPROM eraser are hazardous, 
which is why they have interlock switches that disable the lamps when 

You are going to get a _lot_ more UVA exposure than UVB outdoors, but who 
knows. You aren't going to get much UVC outdoors though.

A typical T1-3/4 UV led doesn't put out anywhere near the energy that a 
bi-pin/fluorescent lamp does, so unless you had a large array of high 
output UV leds, I really wouldn't expect all that much from them.

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