Re: Anyone know what type of plastic Commodore computers are manufactured from?

It's good to hear from someone who knows about the chemistry related to 
this subject.  I tend to leave the cases as-is, or just wash with soap 
and water.  I store computers out of the light.
Bill

>
>
> I have looked at the retr0brite website, and gone throgh all the 
> information there.
>
> It is my opinion that this procedure has not been adequately tested, 
> and there is a possibility that this procedure may cause long term 
> damage to the plastic.
>
> I am a chemist and have some experience testing resins.
>
> The retr0brite information mentions a white "bloom" on the plastic 
> from over treatment.  This condition is permanent.  It also represents 
> chemical damage to the plastic.
>
> A common procedure to determine the chemical resistance of polymers, 
> is to put various reactive chemicals on the surface and determine 
> whether, and how much time it takes for noticeable chemical damage to 
> occur.  This usually shows up as a white "bloom", but this is not the 
> only damage. Polymers can also suffer damage that is not visible, but 
> causes the polymer to lose its strength and prematurely "age".
>
> The retr0brite information says that you should be careful not to over 
> use the chemicals so that the white "bloom" does not occur.  But this 
> does not necessarily mean that chemical damage has not occured.  If it 
> takes x amount of time to create the white "bloom", then using it for 
> half that time probably means that half the damage has occured.  
> Whether the damage is visible is not the real question here.
>
> It would take aging tests to determine whether the plastic is damaged 
> from the retr0brite procedure.  I do not see any indication that 
> retr0brite treated plastics have been subjected to aging tests.
>
>
>
>
>
>
> On Fri, 23 Jul 2010, Bill Degnan wrote:
>
>>
>> Search for "retr0brite project"
>> Bd
>>
>>
>>
>



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