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

From: William Levak <wlevak_at_SDF.LONESTAR.ORG>
Date: Wed, 28 Jul 2010 03:46:06 +0000 (UTC)
Message-ID: <Pine.NEB.4.64.1007280336510.8579@sdf.lonestar.org>
Mild soap is good, not the harsh soap used in laundry and dishwasher 
detergents.  I also use alcohol to clean dirt that does not come off with 
soaps.  91% isopropyl is good because the water evaporates with the 
alcohol (important for electronic components).

The retr0brite documentation recommended waxing the plastic with UV 
absorbing wax.  That's probably a good idea, but definitely use a wax 
designed for plastics.  It's not the wax that's the problem, but the 
solvent the wax is disolved in.

On Tue, 27 Jul 2010, B Degnan wrote:

>
> 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
>>> 
>>> 
>>> 
>> 
>
>
>
>      Message was sent through the cbm-hackers mailing list
>

wlevak@sdf.lonestar.org
SDF Public Access UNIX System - http://sdf.lonestar.org

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Received on 2010-07-28 04:00:15

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