20 Sep
2010
20 Sep
'10
12:50 p.m.
I know that there has been a tremendous amount of talk about removing yellowing from
vintage equipment, but going forward, does anyone have any suggestions for helping prevent
yellowing of equipment on display, short of keeping them in a dark cave? I have a couple
of Apple II's that are in excellent condition with minimal yellowing and would like to
put them on display without having to worry about damage to the plastic.
-Mardy
20 Sep
20 Sep
1:37 p.m.
I believe the best you can do is to prevent strong UV exposure.
However, there are indications that no matter what you do, some
yellowing will occur due to the breakdown of fire retardent additives
to the plastic. It is believed that UV exposure accelerates this
breakdown.
--
"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
<http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/>
Legalize Adulthood! <http://legalizeadulthood.wordpress.com>
2:11 p.m.
On 20 Sep 2010 at 12:50, Marden P. Marshall wrote:
I know that there has been a tremendous amount of talk
about removing
yellowing from vintage equipment, but going forward, does anyone have
any suggestions for helping prevent yellowing of equipment on display,
short of keeping them in a dark cave? I have a couple of Apple II's
that are in excellent condition with minimal yellowing and would like
to put them on display without having to worry about damage to the
plastic.
Pack the equipment away with some dessicant and some activated
charcoal (to absorb any outgassing products) and stick it in cold
storage.
--Chuck
2:31 p.m.
On Mon, Sep 20, 2010 at 2:11 PM, Chuck Guzis <cclist at sydex.com> wrote:
On 20 Sep 2010 at 12:50, Marden P. Marshall wrote:
Frankly, that seems a bit much. Given that there are ways to reverse
that yellowing if it occurs (google "retrobrite" for more info), I'd
say that simply limiting exposure to UV is an adequate measure. If
things happen anyway, at least you'll know it can be fixed.
Mike
I know that there has been a tremendous amount of
talk about removing
yellowing from vintage equipment, but going forward, does anyone have
any suggestions for helping prevent yellowing of equipment on display,
short of keeping them in a dark cave? ?I have a couple of Apple II's
that are in excellent condition with minimal yellowing and would like
to put them on display without having to worry about damage to the
plastic.
Pack the equipment away with some dessicant and some activated
charcoal (to absorb any outgassing products) and stick it in cold
storage.
--Chuck
2:54 p.m.
On 20 Sep 2010 at 14:31, Michael Kerpan wrote:
Frankly, that seems a bit much. Given that there are
ways to reverse
that yellowing if it occurs (google "retrobrite" for more info), I'd
say that simply limiting exposure to UV is an adequate measure. If
things happen anyway, at least you'll know it can be fixed.
There are a number of articles that have been published by
conservators for museums that limiting UV exposure doesn't prevent
the degradation of plastics.
Indeed, it's a big headache now for museums and no one's come up with
any satisfactory answer to the problem. Cold storage at least slows
the process.
I've had gear packed away (in the dark) for 20 years that was in good
shape cosmetically but now is yellowed. At no time did the stuff get
any appreciable exposure to UV (or ozone, for that matter). The
forumulations used in some of the plastics are simply unstable.
Most notably, I had an old Apple color monitor stored in a black
plastic wrap. When I went to retrieve it, I found that several bits
and pieces had spontaneously detached themselves from the unit--the
plastic was so brittle you could break it right off with a minimum of
force.
--Chuck
3:07 p.m.
On Sep 20, 2010, at 2:54 PM, Chuck Guzis wrote:
On 20 Sep 2010 at 14:31, Michael Kerpan wrote:
So it sounds like much of the vintage equipment that this community has been rescuing from
the landfills will ultimately turn into dust, in spite of our best efforts. And I thought
that capacitors going bad was a pain...
-Mardy
Frankly, that seems a bit much. Given that there
are ways to reverse
that yellowing if it occurs (google "retrobrite" for more info), I'd
say that simply limiting exposure to UV is an adequate measure. If
things happen anyway, at least you'll know it can be fixed.
There are a number of articles that have been published by
conservators for museums that limiting UV exposure doesn't prevent
the degradation of plastics.
Indeed, it's a big headache now for museums and no one's come up with
any satisfactory answer to the problem. Cold storage at least slows
the process.
I've had gear packed away (in the dark) for 20 years that was in good
shape cosmetically but now is yellowed. At no time did the stuff get
any appreciable exposure to UV (or ozone, for that matter). The
forumulations used in some of the plastics are simply unstable.
Most notably, I had an old Apple color monitor stored in a black
plastic wrap. When I went to retrieve it, I found that several bits
and pieces had spontaneously detached themselves from the unit--the
plastic was so brittle you could break it right off with a minimum of
force.
--Chuck
3:32 p.m.
On 20 Sep 2010 at 15:07, Marden P. Marshall wrote:
So it sounds like much of the vintage equipment that
this community
has been rescuing from the landfills will ultimately turn into dust,
in spite of our best efforts. And I thought that capacitors going bad
was a pain...
Cue Shel Silverstein "Pastic"...
Here's an interesting page about plastic conservation:
http://www.conservationregister.com/careplastics.asp?id=4
Also, check around for publications by the French POPART conservation
effort.
It'll all end up in the Pacific Gyre, I'm afraid. Centuries from
now, people will wonder how we lived.
I seem to be seeing the same thing happening with internet content.
Things I've bookmarked a decade or more ago can't be found in any
form online (not even in archive.org). Good thing that I saved some
of it.
--Chuck
4:03 p.m.
On Mon, Sep 20, 2010 at 3:32 PM, Chuck Guzis <cclist at sydex.com> wrote:
I seem to be seeing the same thing happening with internet content.
Things I've bookmarked a decade or more ago can't be found in any
form online (not even in archive.org). Good thing that I saved some
of it.
--Chuck
Chuck,
I'm still looking for the plans to that super-electromagnet stargate
traveling time machine that was online about '93 - if it's in your archive.
=Dan
4:32 p.m.
On 20 Sep 2010 at 16:03, Dan Roganti wrote:
I'm still looking for the plans to that
super-electromagnet stargate
traveling time machine that was online about '93 - if it's in your
archive.
Not mine, but I heard that they'd dropped it because of
unavailability of flux capacitors and ZPMs.
--Chuck
5:08 p.m.
On 20 Sep 2010 at 16:03, Dan Roganti wrote:
> I'm still looking for the plans to that super-electromagnet stargate
> traveling time machine that was online about '93 - if it's in your
> archive.
On Mon, 20 Sep 2010, Chuck Guzis wrote:
Not mine, but I heard that they'd dropped it
because of
unavailability of flux capacitors and ZPMs.
Alas, Jeri Ellsworth, the only person that I know that has any real chance
of making a homemade flux capacitor, is too young to have an obsession
with trying to go back top the '60s.
--
Grumpy Ol' Fred cisin at xenosoft.com
4:58 p.m.
On Mon, 20 Sep 2010, Dan Roganti wrote:
I'm still looking for the plans to that
super-electromagnet stargate
traveling time machine that was online about '93 - if it's in your archive.
Well, if you ever find the plans, you can go back to '93 and make sure
that they remail available.
Hmmm. It seems that you haven't done so, and therefore never will. :-(
--
Grumpy Ol' Fred cisin at xenosoft.com
5:06 p.m.
In article <4C975446.1458.C0728A at cclist.sydex.com>,
"Chuck Guzis" <cclist at sydex.com> writes:
Here's an interesting page about plastic
conservation:
http://www.conservationregister.com/careplastics.asp?id=4
It basically says: "contact a conservator". Not very helpful or
interesting IMO.
--
"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
<http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/>
Legalize Adulthood! <http://legalizeadulthood.wordpress.com>
5:44 p.m.
On 20 Sep 2010 at 15:06, Richard wrote:
It basically says: "contact a conservator".
Not very helpful or
interesting IMO.
What I gather from my reading is that no one's got any good
procedures yet, other than low-temperature storage. Basically,
plastics are inherently unstable and keeping them around for future
generations is going to be a tough nut to crack.
POPART has perhaps the best-funded conservation research project on
plastics, so it's a site to watch for news.
--Chuck
5:48 p.m.
On Mon, Sep 20, 2010 at 1:54 PM, Chuck Guzis <cclist at sydex.com> wrote:
On 20 Sep 2010 at 14:31, Michael Kerpan wrote:
It's usually the oxygen that's involved in the breakdown. After
Retrobrite, it's recommended to spray them with a light sealant like
satin acrylic lacquer. (Note that this is not a heavy paint on
lacquer like people think of with lacquering a piece of furniture).
Same thing used in some art communities to protect paper projects,
paintings, etc.
Marty
Frankly, that seems a bit much. Given that there
are ways to reverse
that yellowing if it occurs (google "retrobrite" for more info), I'd
say that simply limiting exposure to UV is an adequate measure. If
things happen anyway, at least you'll know it can be fixed.
There are a number of articles that have been published by
conservators for museums that limiting UV exposure doesn't prevent
the degradation of plastics.
Indeed, it's a big headache now for museums and no one's come up with
any satisfactory answer to the problem. ?Cold storage at least slows
the process. 
1:26 p.m.
On 20 Sep 2010 at 16:48, Martin Goldberg wrote:
It's usually the oxygen that's involved in the
breakdown. After
Retrobrite, it's recommended to spray them with a light sealant like
satin acrylic lacquer. (Note that this is not a heavy paint on
lacquer like people think of with lacquering a piece of furniture).
Same thing used in some art communities to protect paper projects,
paintings, etc.
Do you have a reference for this? The literature that I've seen
pretty much faults the stabilizers and plasticizers as well as
outgassing of same.
I'd think that if a simple lacquer coating worked, museums could save
a lot of money by not pursuing grants and holding conferences,
publishing papers and books and generally agonizing about the
subject.
FWIW, I've used a product called "Midas Finish Seal Lacquer" marketed
by Rio Grande (the jewelers' supply house). It's primarily used to
seal jewelry finishes for display and can be easily removed.
--Chuck
6:12 p.m.
Chuck - the yellowing has to do with a breakdown of the flame
retardent in the plastic. The bromine free readicals involved in the
breakdown look for Oxygen to attach themselves to. Per the chemical
engineer that came up with the Retrobrite process:
"Retr0bright reverses the yellowing process, it's not a permanent
cure. If the surface of the plastic is still open to the air, it will
yellow again, as the bromine free radical reaction is reversible
(otherwise, we wouldn't be able to reverse it... )
The permanent fix it is to coat it with clear satin acrylic lacquer to
seal the surface off from the air. No oxygen, no oxidation; simple,
really......"
The chemical reaction of the breakdown process as well as the recovery
process are well documented at the Retrobrite wiki:
http://retr0bright.wikispaces.com/
Hope that answers you question. I've used the process on several
items myself about two years ago (Apple III case, white bally computer
case) to great success. So far no degradation of the plastic, and no
re-yellowing.
Marty
On Tue, Sep 21, 2010 at 12:26 PM, Chuck Guzis <cclist at sydex.com> wrote:
On 20 Sep 2010 at 16:48, Martin Goldberg wrote:
It's usually the oxygen that's involved
in the breakdown. ?After
Retrobrite, it's recommended to spray them with a light sealant like
satin acrylic lacquer. ?(Note that this is not a heavy paint on
lacquer like people think of with lacquering a piece of furniture).
Same thing used in some art communities to protect paper projects,
paintings, etc.
Do you have a reference for this? ?The literature that I've seen
pretty much faults the stabilizers and plasticizers as well as
outgassing of same.
I'd think that if a simple lacquer coating worked, museums could save
a lot of money by not pursuing grants and holding conferences,
publishing papers and books and generally agonizing about the
subject.
FWIW, I've used a product called "Midas Finish Seal Lacquer" marketed
by Rio Grande (the jewelers' supply house). ?It's primarily used to
seal jewelry finishes for display and can be easily removed.
--Chuck
22 Sep
22 Sep
6:18 a.m.
In article <AANLkTi=ioS5-mp3EQsp_kgihkUANRe2ekQ9FEFqEvPO+ at mail.gmail.com>,
Martin Goldberg <wgungfu at gmail.com> writes:
Hope that answers you question. I've used the
process on several
items myself about two years ago (Apple III case, white bally computer
case) to great success. So far no degradation of the plastic, and no
re-yellowing.
Did you apply the acrylic lacquer?
--
"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
<http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/>
Legalize Adulthood! <http://legalizeadulthood.wordpress.com>
11:49 a.m.
On 21 Sep 2010 at 17:12, Martin Goldberg wrote:
Hope that answers you question. I've used the
process on several
items myself about two years ago (Apple III case, white bally computer
case) to great success. So far no degradation of the plastic, and no
re-yellowing.
Martin, I've followed the Retrobrite (forgive me for not using the
"LEET" spelling) saga since nearly its inception.
To date, I know of not a single museum conservationist who agrees
wtih or uses the retrobrite process, even though all agree that
plastics degradation is a serious problem.
If the process were vetted by POPART, I would feel much better about
it.
Retrobrite also does not address the loss or breakdown of
plasticizers (e.g. that Apple monitor that was spontaneously
disintegrating. I also have a tape drive bezel that's behaving
similarly). Nor does it address the breakdown in high-density
structural polyurethane foam used on some enclosures.
I submit that the problem with plastics is far more complex and
problematical than the Retrobrite folks make it to be.
--Chuck
1:58 p.m.
In article <4C99C318.19292.F4685 at cclist.sydex.com>,
"Chuck Guzis" <cclist at sydex.com> writes:
I submit that the problem with plastics is far more
complex and
problematical than the Retrobrite folks make it to be.
Retrobrite only claims to deal with the yellowing due to the fire
retardent additives; it makes no claims with regard to any of the
other problems with plastics.
I think for a nice looking museum acceptable display you're going to
need to create replicas if you want to give the viewer an idea of what
things looked like when they were first manufactured.
--
"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
<http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/>
Legalize Adulthood! <http://legalizeadulthood.wordpress.com>
20 Sep
20 Sep
4:37 p.m.
Frankly, that seems a bit much. Given that there are
ways to reverse
that yellowing if it occurs (google "retrobrite" for more info), I'd
say that simply limiting exposure to UV is an adequate measure. If
things happen anyway, at least you'll know it can be fixed.
Does the chemical change that causes the yellowing have any other effect?
(e.g. does it make the plastic weaker or more brittle?). If so, can
_those_ effects be reversed? To be honest, I am not over-worried about
the colour of things like Vt100s, but I'd rather they didn;t start
falling apart...
-tony
2:27 p.m.
Maybe SPF 50?
Seriously, I'd say probably limiting exposure to sunlight and/or florescent
lighting. I believe some (all?) clear polycarbonate plastics will filter UV as
well to some degree, so maybe a clear case?
________________________________
From: Marden P. Marshall <mardy at voysys.com>
To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
Sent: Mon, September 20, 2010 11:50:02 AM
Subject: How to prevent yellowing of equipment on display
I know that there has been a tremendous amount of talk about removing yellowing
from vintage equipment, but going forward, does anyone
have any suggestions for
helping prevent yellowing of equipment on display, short
of keeping them in a
dark cave? I have a couple of Apple II's that are in excellent condition with
minimal yellowing and would like to put them on display without having to worry
about damage to the plastic.
-Mardy
9:58 p.m.
Marden P. Marshall wrote:
I know that there has been a tremendous amount of talk
about removing yellowing from vintage equipment, but going forward, does anyone have any
suggestions for helping prevent yellowing of equipment on display, short of keeping them
in a dark cave? I have a couple of Apple II's that are in excellent condition with
minimal yellowing and would like to put them on display without having to worry about
damage to the plastic.
-Mardy
Has anyone looked into sealing the plastic items with a plastic coating?
Spray on acrylic or urethane products?
Possibly dipping in something like fiberglass resin would protect
against the atmosphere. I haven't seen signs of that polymer breaking
down - at least in equipment I have from the early 1970s.
If oxygen is the enemy then almost anything would help...
John :-#)#
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