How to clean 'yellowed' plastic?
Jim K
off. Haven't needed it for about 15 years now. You also might try a
bleach type cleaner.
swi...@hoida.com (Steve Wilson) wrote:
>
> I'm curious about the recommended method and materials for cleaning up
>the yellowed plastic that seems to grow on every piece of computer hardware
>I've ever owned that is more than 1 year old? I just received 2 M100's that
>could use a good scrubbing (not to mention 2 or 3 monitor cases
>around here)...anyone had any luck? TIA
I got one them stupid * in my name
Jim Kajpust - Personal Freedoms - Michigan
http://www.concentric.net/~jkajpust
Steve Wilson
jau
Plastic generally yellows from exposure to the sun. I've cleaned many a case
with Windex, sometimes with very fine cleaning powder. Too aggesssive cleaning
may leave an uneven, patchy looking, surface. Don't use lighter fluid or other
strong solvents. Isopropryl alchohol will take off things like pen ink, crayon,
etc. but not the yellowing. Maybe someone out there has a better idea.
FWIW.
J.
In article <71r0i8$r2q$1...@news.inc.net>, swi...@hoida.com says...
Frank Durda IV
: I'm curious about the recommended method and materials for cleaning up
: I've ever owned that is more than 1 year old? I just received 2 M100's that
: could use a good scrubbing (not to mention 2 or 3 monitor cases
: around here)...anyone had any luck? TIA
There are two major sources of yellowing on the plastics Tandy and
other manufacturers used during the 1980s and early 1990s:
1. Tobacco smoke and other environmental hazards. Particularly on
monitors or computer cases containing monitors or open frame switching
power supplies, the tar from tabacco is electrostatically attracted
to these cabinets and not only coats the cases with a yellow film,
this film also captures dust, and is most evident in and around
CRT high voltage assemblies. Eventually, this can cause unexpected
high voltage arcing and component destruction.
Most common household cleaners, such as Windex (sprayed onto cloth
and THEN rubbed on the surfaces) will remove most of this material.
NEVER spray water-based surfacents directly onto computers as the
drips and overspray can get into the circuitry or cause staining.
Even after using a the cloth method, allow lots of time for any
stray liquid to evaporate before applying power.
This type of yellowing is usually uneven, and if it won't rub off
immediately when exposed to a mild cleaning agent, see problem #2.
2. Ultraviolet light. Most manufacturers (including Tandy and most of
its OEMs) did not bother to purchase plastics with UV stabilizing
compounds (it costs more or they originally planned to paint the case,
as was the case with all Tandy units made in late 1982 and early 1983,
when Tandy switched to non-gray cases).
Units that have been exposed frequently to direct sunlight (and
most types of flourescent lighting but at a slower rate) will
permanently change color, with the most frequently-used materials
moving eventually to a near-orange color. At the same time, some
materials will begin to shed/flake their outer finish, particularly
if the material was buffed, sanded or of a thermal setting plastic
type. In extreme cases, the plastic will become brittle. Early
symptoms of this will show at stress points, such as screw mounting
points, which will crack or break on the outer surfaces of the case
or points that are habitually rubbed, such as around buttons and other
controls.
There is no way to fix UV damage. You can conceal all but the latter
stages of deterioration by painting the surfaces with an oil-based
paint, except for transparent parts such as Model 100/102/200/600
screen covers. Most plastics will stop degrading when the source of
UV goes away.
As it turns out, the Tandy models that were spot-painted, either as
artistic trim or to conceal defects in the plastic moldings (these
include the Model 4/4D/4P/12/16/2000/6000/Coco II/III models) or
those that were completely painted (Model I/II/III/original Coco)
are protected from most UV damage, at least in the painted areas.
Go back to cause #1 on these cases, but don't rub too hard.
Some units contain plastic parts made from different types of plastic
which are affected by UV unevenly. The DMP 2200 is one such example,
and most units have now had their covers turn almond color, while the
bottom half of the plastic case looks the same off-white color as when
it was in the stores. This type of color change is entirely caused
by UV and the use of two different types of plastic or two different
batches of poorly mixed plastic, since both halves would have been
equally exposed to tabacco smoke and other airborne environmental
hazards.
Frank Durda IV - only these addresses work:|"I picked up a Magic 8-Ball the
<uhclem.dec98%nemesis.lonestar.org> | other day and it said 'Outlook
| not so good'. I said 'Sure,
This Anti-spam address expires Dec. 31st | but Microsoft still ships it."
Copr. 1998, ask before reprinting.
Paul Binns
Steve Wilson wrote in message <71r0i8$r2q$1...@news.inc.net>...
>
> I'm curious about the recommended method and materials for cleaning
up
>the yellowed plastic that seems to grow on every piece of computer hardware
>I've ever owned that is more than 1 year old? I just received 2 M100's
that
>could use a good scrubbing (not to mention 2 or 3 monitor cases
>around here)...anyone had any luck? TIA
Not once yellowed. But from my experience there are two
things that cause the yellowing: bright sunlight, and chemical
cleaning compounds.
When I had my storefront office, the Xerox service technician
came in to service the photocopier. He used some sort of
cleaning compound on the exterior of the photocopier (it
wasn't that dirty, but ...). Within a couple of months, the
case was badly yellowed.
And then when I moved out of that office, I got to compare
the two computers, one from the reception area (which
was exposed to direct sunlight) and the other from my
office (which only had one small window covered by a
blind). The one from the front was a decidedly ugly
yellow, whereas mine was by comparison "pristine".
Aged plastic is, in my experience, permanently uglified.
-=Paul=-
Jim K
figure out why I had such problems reading it afterwards. ;-).
uhclem...@nemesis.lonestar.org (Frank Durda IV) wrote:
> There is no way to fix UV damage. You can conceal all but the latter
> stages of deterioration by painting the surfaces with an oil-based
> paint, except for transparent parts such as Model 100/102/200/600
> screen covers. Most plastics will stop degrading when the source of
> UV goes away.
I got one them stupid * in my name
kevin tripcony
Frank Durda IV wrote in message ...
>Steve Wilson (swi...@hoida.com) wrote:
>: I'm curious about the recommended method and materials for cleaning up
>: the yellowed plastic that seems to grow on every piece of computer
hardware
>: I've ever owned that is more than 1 year old? I just received 2 M100's
that
>: could use a good scrubbing (not to mention 2 or 3 monitor cases
>: around here)...anyone had any luck? TIA
>
> There is no way to fix UV damage. You can conceal all but the latter
> stages of deterioration by painting the surfaces with an oil-based
> paint, except for transparent parts such as Model 100/102/200/600
> screen covers. Most plastics will stop degrading when the source of
> UV goes away.
>
Pete Cervasio
On 05 Nov 1998 07:18:57 PST, j*kaj...@concentric.net (Jim K) wrote:
>uhclem...@nemesis.lonestar.org (Frank Durda IV) wrote:
>
>> There is no way to fix UV damage. You can conceal all but the latter
>> stages of deterioration by painting the surfaces with an oil-based
>> paint, except for transparent parts such as Model 100/102/200/600
>> screen covers. Most plastics will stop degrading when the source of
>> UV goes away.
>I wish I had your advice years ago. I painted my M100 and couldn't
>figure out why I had such problems reading it afterwards. ;-).
My problem is the coffee that just got spewed all over my monitor
after reading your post. It's a good thing Frank's post had tips on
cleaning computers, and an equally good thing that I read *his* post
first.
Typing blind,
Pete c.
=====================================================================
I'm really cervasio at airmail dot net if you want to email me, or go
to http://www.kjsl.com/trs80/ and pick the email link there.
=====================================================================
Jim K
brittle, or the surface getting "icky." While I haven't tried it on
any electronics stuff, ArmorAll worked quite nicely on my 10 year old
Chevy. The plastic trim would start to act like it was "dried out" and
show some crumbling. A couple of heavy treatments with ArmorAll seemed
to fix things right up.
swi...@hoida.com (Steve Wilson) wrote:
> I'm curious about the recommended method and materials for cleaning up
>the yellowed plastic that seems to grow on every piece of computer hardware
>I've ever owned that is more than 1 year old?
WALT SAYS
of case "yellowing". Strange, this must only be an "indoors" thing.
Some time ago I had discarded some old monitor cases on a junk pile, which
I had been creating in the rear of my property, waiting for the "spring
cleanup" campaign in our area. After a month's time on the pile, the once
very yellowed cases, being outdoors in the elements, were now a grayish
chaulky white. Experimenting, I cleaned a portion of a case with a cleaner,
then buffed it with a silione clear lubricant. The end result was a portion of
a case which looked like it had just come from the manufacturer's mold.
Unable to let this "find" rest, I removed the "inards" of a very yellowed
Apple IIe Platinum and let the cases to the outdoor elements for about 2
months, (turning and repositioning the pieces periodically) after which time
using a cleaner and a silicone buff, rendered me a pristine looking IIe.
Tinkering with old sets is a hobby of mine, and one of the biggest problem
is the discoloration of cases. I presently have 3 Tandy DM printer cases
"weathering". In about 3 weeks time - I notice an improvement in color, but as
of yet, not what I hope for. These I believe are the worst of the group for
"yellowing" and if they fair well, I am sure there is hope for all.
Some cleaners I have found to work well on removing stains,ink,adhesives and
marks are "Spray 9" (industrial), "Westley's Bleach White" (automotive white
wall cleaner) and a solution of "real lemon juice" and "table salt".
A real fine steel wool pad when dipped in cooking oil, will remove minor
scratches and embedded marks if the area is rubbed gently and with caution as
not to over do. Once the mark is removed clean and buff the case.
Well, thought I'd stick my two cents in.
If this helps anyone, I am pleased.
I do hope that no one will be foolish enough to try my experiment without
removing the "inards" of the cases.
Waltsays
Charles Stephens
W> Unable to let this "find" rest, I removed the "inards" of a very
W> yellowed Apple IIe Platinum and let the cases to the outdoor
W> elements for about 2 months, (turning and repositioning the pieces
W> periodically) after which time using a cleaner and a silicone
W> buff, rendered me a pristine looking IIe.
Have you tried the cleaner (which one) and the buff without the
weathering. I am in more of a hurry.
cfs
--
Charles F. Stephens = cfs AT eng.sun.com
Software Psychic and Illuminary =
Solaris Network Sustaining = "We know what you buy, we know where you
Solaris Software = live." -- Wesayso Corp.
Sun Microsystems, Inc. =
Menlo Park, California, USA =
John Troxell
found that Ammonia and water was one of the best cleaners for
Nicotine/smoke.
However, that Acid Rain trick sounds pretty neat. Knew it had to be good
for something...how did that saying go?
FreeUsFromWillie
John T
scoobydoo
ha-ha
hee-hee
--
____________________
Who's General Failure & why's he reading my disk?
Scoobydoo :-)
Please reply to GROUP
John Troxell wrote in message
<22330-36...@newsd-113.bryant.webtv.net>...
Comet
>
> I'm curious about the recommended method and materials for cleaning up
> the yellowed plastic that seems to grow on every piece of computer hardware
> could use a good scrubbing (not to mention 2 or 3 monitor cases
> around here)...anyone had any luck? TIA
See http://www.value.net/~thedock/c100/recon.html where Richard Hanson has a
set of pictures showing the reconditioning process he user for M100s.
--------
Comet -- Club 100