[Coco] RE: [Color Computer] Case & Keyboard Restoration

[jdaggett at gate.net]

Glen

Correct on the causes of yellowing. 

Almost all plastics when formulated are clear. Pigment is added 
during mixing and before injection mold process. Once the pigment 
itself starrtts to discolor there is no real means of cleaning that 
discoloration. Surface dirt and stuff can be cleaned. 

Krylon now makes a paint that is formulated to stick to plastics 
better. Generally paint does not like to stick to plastic unless one 
cures the paint at an elevated temperature. The problem is the 
better the cure, the higher the temperature. Sadly enough, most 
common paints cure at temperatures that start to deform the plastic 
or alter its mechanical strength.

I would try the Krylon paint. There are some industrial paints that 
are not to bad but are not generally available in small quantities to 
the general public.

james




On 25 Jan 2005 at 17:30, Glen VanDenBiggelaar wrote:

To:             	ColorComputer at yahoogroups.com
From:           	"Glen VanDenBiggelaar" 
<glenvdb at hotmail.com>
Date sent:      	Tue, 25 Jan 2005 17:30:22 -0700
Copies to:      	Subject:        	[Coco] RE: [Color Computer] 
Case & Keyboard Restoration
Send reply to:  	ColorComputer at yahoogroups.com,
	CoCoList for Color Computer Enthusiasts 
<coco at maltedmedia.com>
	<mailto:coco-
request at maltedmedia.com?subject=unsubscribe>
	<mailto:coco-
request at maltedmedia.com?subject=subscribe>

>  Most of the
> "Yellowing" is ether 1 of 2 things, Tar from Smoking or UV from
> sunlight. If its tar, that can ber removed by a good cleaning agent,
> if its UV, it has discollered the plastic, not just the pain on the
> surface. I have been trying to get the yellow of my white CoCo 1, but
> it looks like I may have to re-pain