21 Dec
1997
21 Dec
'97
2:31 p.m.
I find that has alot to do with the amount of certain resins in the
plastics. It's hard to keep a controlled mix on those injection molders
sometimes... I speak from experience. :)
At 04:32 PM 12/21/97 -0600, you wrote:
I was also lucky enough to find an Adam complete in box
a few months
back. Mine, unfortunately, seems to have gotten "sunburned"
(yellowed). The strange thing is, some of the keys on the keyboard are
perfectly white, some are slightly yellowed, and some are very badly
yellowed (spacebar especially). What is the condition of your
keyboards?
- John Higginbotham
- limbo.netpath.net
22 Dec
22 Dec
1:22 a.m.
I have several old HP computers that have done the same thing. Is there
any way to repair or restore the color?
Joe
At 11:31 PM 12/21/97 -0500, you wrote:
I find that has alot to do with the amount of certain
resins in the
plastics. It's hard to keep a controlled mix on those injection molders
sometimes... I speak from experience. :)
At 04:32 PM 12/21/97 -0600, you wrote:
I was also lucky enough to find an Adam complete
in box a few months
back. Mine, unfortunately, seems to have gotten "sunburned"
(yellowed). The strange thing is, some of the keys on the keyboard are
perfectly white, some are slightly yellowed, and some are very badly
yellowed (spacebar especially). What is the condition of your
keyboards?
- John Higginbotham
- limbo.netpath.net
21 Dec
21 Dec
11:36 p.m.
At 09:22 AM 12/22/97, you wrote:
I have several old HP computers that have done the same
thing. Is there
any way to repair or restore the color?
Not that I know of. It's not exactly smoke residue that you can wipe off,
it's in the plastic itself. You could try some paint, but it could get messy.
- John Higginbotham
- limbo.netpath.net
22 Dec
22 Dec
3:04 a.m.
New subject: Plastic rot
At 09:22 12/22/97, you wrote:
I have several old HP computers that have done the same
thing. Is there
any way to repair or restore the color?
No, there (currently) isn't. And the real bother isn't the discoloration,
but the accompanying embrittlement -- I picked up a mustard-colored HP
terminal once and had a piece of the case break off in my hand.
A bloke who was researching this at the Science Mus. in London wrote an
article for the ANALYTICAL ENGINE in which he basically said that there was
no reversing the effect, and the only way you could limit the deterioration
was to keep the artifact in near-total darkness. I also asked the
Smithsonian and they concurred with this.
__________________________________________
Kip Crosby engine(a)chac.org
http://www.chac.org/index.html
Computer History Association of California
6:35 a.m.
New subject: Plastic rot
At 09:04 AM 12/22/97 -0800, you wrote:
At 09:22 12/22/97, you wrote:
Does applying Armor-All or any of the other plastic preservatives
prevent the hardening? I've never tried it on the hard palstics, only vinyl.
Joe
I have several old HP computers that have done the
same thing. Is there
any way to repair or restore the color?
No, there (currently) isn't. And the real bother isn't the discoloration,
but the accompanying embrittlement -- I picked up a mustard-colored HP
terminal once and had a piece of the case break off in my hand.
A bloke who was researching this at the Science Mus. in London wrote an
article for the ANALYTICAL ENGINE in which he basically said that there was
no reversing the effect, and the only way you could limit the deterioration
was to keep the artifact in near-total darkness. I also asked the
Smithsonian and they concurred with this.
__________________________________________
Kip Crosby engine(a)chac.org
http://www.chac.org/index.html
Computer History Association of California 
5:39 a.m.
New subject: Plastic rot
At 09:04 AM 12/22/97 -0800, you wrote:
Primary cause of aging in most plastics including vinyls is UV rays.
Meaning, keep 'em out of direct sun!
Jason D.
At 09:22 12/22/97, you wrote:
Does applying Armor-All or any of the other plastic preservatives
prevent the hardening? I've never tried it on the hard palstics, only vinyl.
Joe
> I have several old HP computers that have done the
same thing. Is there
any way to repair or restore the color?
No, there (currently) isn't. And the real bother isn't the discoloration,
but the accompanying embrittlement -- I picked up a mustard-colored HP
terminal once and had a piece of the case break off in my hand.
A bloke who was researching this at the Science Mus. in London wrote an
article for the ANALYTICAL ENGINE in which he basically said that there was
no reversing the effect, and the only way you could limit the deterioration
was to keep the artifact in near-total darkness. I also asked the
Smithsonian and they concurred with this.
__________________________________________
Kip Crosby engine(a)chac.org
http://www.chac.org/index.html
Computer History Association of California
9:53 a.m.
New subject: Plastic rot
Snip!
Flourescent lights are also to blame. Standard museum
practice is to put
filters over the fixtures.
William Donzelli
william(a)ans.net
Oh, but in my case, really dislike fluorescents. Unnatural light,
flickers with monitors and hard on my eye. So that it be halogen or
indescent (sp?) lamps where allowed. Note the fluor not flour---.
:)
Jason D.
11:10 p.m.
New subject: Plastic rot
At 07:39 PM 12/22/97 +0000, you wrote:
Should you only drive your Corvette on cloudy days?
Seasons greetings
Charlie Fox
> At 09:04 AM 12/22/97 -0800, you wrote:
> >At 09:22 12/22/97, you wrote:
> >>I have several old HP computers that have done the same thing. Is there
> >>any way to repair or restore the color?
> >
> >No, there (currently) isn't. And the real bother isn't the
discoloration,
> >but the accompanying embrittlement -- I picked up a mustard-colored HP
> >terminal once and had a piece of the case break off in my hand.
> >
> >A bloke who was researching this at the Science Mus. in London wrote an
> >article for the ANALYTICAL ENGINE in which he basically said that there
was
> >no reversing the effect, and the only way you
could limit the
deterioration
> >was to keep the artifact in near-total
darkness. I also asked the
> >Smithsonian and they concurred with this.
> >
> >__________________________________________
> >Kip Crosby engine(a)chac.org
> > http://www.chac.org/index.html
> >Computer History Association of California
>
> Does applying Armor-All or any of the other plastic preservatives
> prevent the hardening? I've never tried it on the hard palstics, only
vinyl.
Joe
>
Primary cause of aging in most plastics including vinyls is UV rays.
Meaning, keep 'em out of direct sun!
Jason D.
> > 
3:46 p.m.
New subject: Plastic rot
A bloke who was researching this at the Science Mus. in
London wrote an
article for the ANALYTICAL ENGINE in which he basically said that there was
no reversing the effect, and the only way you could limit the deterioration
was to keep the artifact in near-total darkness. I also asked the
Smithsonian and they concurred with this.
I guess that means those of us that are forced to keep sizable portions of
our collections in a storage unit are actually lucky then, as it means we
are keeping them in the correct light levels. Hmmm.
On a simular note, I'm in the process of seeing about getting my Atari 800
up and running. It apparently had a piece of black plastic foam on the lid
about the where the two cartridges go.
Foam rubber is _EVIL_, it deteriorates, and it can really make a mess.
I've seen it make some really sickening messes. A good example is it can
pock the finish on a fine violin. This is the first time I think I've seen
it used in a computer though.
This sort of goes against principles when it comes to restoring things, or
keeping them in their original form, but if you have systems with foam
rubber in it, it would be best to remove it.
Zane
| Zane H. Healy | UNIX Systems Adminstrator |
| healyzh(a)ix.netcom.com (primary) | Linux Enthusiast |
| healyzh(a)holonet.net (alternate) | Classic Computer Collector |
+----------------------------------+----------------------------+
| For Empire of the Petal Throne and Traveller Role Playing, |
| see http://www.dragonfire.net/~healyzh/ |
| For the collecting of Classic Computers with info on them. |
| see http://www.dragonfire.net/~healyzh/museum.html |
23 Dec
23 Dec
12:26 a.m.
New subject: Plastic rot
Foam rubber is _EVIL_, it deteriorates, and it can really make a mess.
I've seen it make some really sickening messes. A good example is it can
pock the finish on a fine violin. This is the first time I think I've seen
it used in a computer though.
Hmmm. I flunked freshman chemistry, so maybe I'm wrong, but isn't
foam rubber made with formaldehyde?
Jeff
1:43 a.m.
New subject: Plastic rot
At 08:26 AM 12/23/97 -0600, you wrote:
Hmmm. I flunked freshman chemistry, so maybe I'm
wrong, but isn't
foam rubber made with formaldehyde?
I think formaldehyde is used in the process, and that some of it does come
out in the finished foam, but there are supposedly strict rules about how
much is allowed in the finished product.
- John Higginbotham
- limbo.netpath.net
4:50 a.m.
New subject: Plastic rot
At 21:46 12/22/97 -0800, Zane wrote:
This sort of goes against principles when it comes to
restoring things, or
keeping them in their original form, but if you have systems with foam
rubber in it, it would be best to remove it.
Oh, you bet. When we got the SDS 930 (14 racks,) the doors of all the
modules were lined with black isocyanate insulating foam, and it had begun
to liquefy. We got that outa there in no time.
__________________________________________
Kip Crosby engine(a)chac.org
http://www.chac.org/index.html
Computer History Association of California
10:07 a.m.
New subject: Plastic rot
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1:37 p.m.
New subject: Plastic rot
Some DEC machines use a similar foam either to hold
the boards in place
(the PDP8/e does this) or as a fan filter. Needless to say, when the foam
disintegrates, it then puts more muck into the machine than it ever kept
out. This is bad news on a demountable hard disk :-(.
Many larger machines use the stuff to kill some of the noise. IBMs
generally are loaded with it. But in the future, the Sun E150 may top
list in terms of gooiness.
Most DEC collectors that I know remove this foam as
soon as they get the
machines. I always do. Sure, it's not original, but at least the machine
will keep running.
Some of the stuff is rather stable - 30 years old and only a bit
discolored. At least the stuff is very easy to replace and restore. I
suppose the thing to do is find this stuff and get a bunch.
William Donzelli
william(a)ans.net
24 Dec
24 Dec
10:22 a.m.
New subject: Plastic rot
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1:44 p.m.
New subject: Plastic rot
Tony Duell wrote:
I _hate_ that residue. It makes what I work hardest to clean look
absolutely filthy. But I leave it there, because further attempts to
clean causes functional damage, not merely aesthetic. (Old Tandy gear,
actually. Hard disks mostly.)
Most of my neighbors get shielded cable. The rest can imagine that the
RFI is an act of God. They think that TV is an act of God.
[Foam]
_Especially_ if you inhale a bit of the stuff. 8-)
Some of the stuff is rather stable - 30 years old
and only a bit
discolored. At least the stuff is very easy to replace and restore. I
Well, it's easy in theory, but it's hard work, and a right pain to do.
Personally I'd rather be tracing logic faults (my crazy mental recreation
- almost as bad as crossword puzzles, I guess :-)). Electrolube 'Label
Remover' does help a bit. suppose the
thing to do is find this stuff and get a bunch.
What I'm doing is removing it and leaving the panels bare - although
there's always enough residue to indicate that said panel was once
covered with this foam. The extra noise doesn't bother me. If at some time in the future I want a 'looks like it just
left the factory' machine
I can buy some suitable foam and stick in on.
Ah, it might be illegal. After all, manufacture of plastic (or rubber)
foam affects the ozone layer and causes global warming. So say some.
--
Ward Griffiths
Two thousand yeare since Bethlehem and still we hear the lie,
that after years of hopes and fears the best part's when we die.
25 Dec
25 Dec
8:50 a.m.
New subject: Plastic rot
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28 Dec
28 Dec
1:39 p.m.
New subject: Plastic rot
Tony Duell wrote:
:-). Actually, Label Remover is not really suitable for that use (it
smells a little like orange oil, and is not a common organic solvent
AFAIK). Now, head cleaner is another matter :-)
Ah, not being familiar with the specific product, I thought it might
contain some of the more amusing volatiles.
As far as I know, the only solvent that _might_ get the rest of the crap
off would be a liberal application of acetone, in quantities that would
drip into the plastic and rubber mechanical parts. That was the case with
couple of printers. On the other hand, acetone is the best thing in the
world for making old typewriter (and impact printer, specifically the
Radio Shack Daisy Wheel II) platens look like new -- a trick I was taught
by one of my RSCC managers when it was occasionally necessary to restore
the hymen of a floor demo prior to delivery to a customer.
Argh!!! Oh well, my machines will have to do without this foam, then.
If they outlaw it, I'll have to start up a little illicit manufactory. I
hold no truck with the "global warming" hysteria.
--
Ward Griffiths
Q: How many "environmentalists" does it take to replace a lightbulb?
A: None. Darkness is part of nature.
- almost as bad as crossword puzzles, I guess :-)).
Electrolube 'Label
Remover' does help a bit.
_Especially_ if you inhale a bit of the stuff. 8-) I _hate_ that
residue. It makes what I work hardest to clean look
absolutely filthy. But I leave it there, because further attempts to
clean causes functional damage, not merely aesthetic. (Old Tandy gear,
What damage?
> actually. Hard disks mostly.)
I haven't tried using acetone on a hard drive yet, because I don't want
the risk of disolving the seals.
> Most of my neighbors get shielded cable. The
rest can imagine that the
> RFI is an act of God. They think that TV is an act of God.
Eh? The foam I'm talking about is a good
insulator, and would have no
effect AFAIK on RFI. Actually, for all some classic computers should
radiate like mad (and I tend to run them with covers removed, etc), I've
never had any problems from people complaining.
I'd thought I'd seen a reference earlier in the thread about some of this
foam having a metallic component. I'll have to scan back, my mind may have
wandered during composition (as it is now).
time in the future I want a 'looks like it just
left the factory' machine
I can buy some suitable foam and stick in on.
Ah, it might be illegal. After all, manufacture of plastic (or rubber)
foam affects the ozone layer and causes global warming. So say some. 
26 Dec
26 Dec
6:38 p.m.
New subject: Plastic rot
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27 Dec
27 Dec
5:51 a.m.
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ard＠p850ug1.demon.co.uk -
engine＠chac.org -
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