Conference 7.286::digital

    
    	The [audio] changer in 1 of my cars is always loaded with CD's
    	and I have never had a problem ... even though the car is shut
    	up tight more often than not.
    
    	If possible, always leave a window or 2 open enough to let SOME
    	air circulate.
    

    I have been carrying my CD library in the car trunk, for exactly the
    same reason, for 3 or 4 years. Winter and Summer, in New England. Havent
    had a problem with it yet. Also my entire library of manuals and
    papers, since I'm on the home-alone program and dont have an office to
    keep them in.
    
    Of course, this answer is like the common  "is it supported" vs
    "does it work"
    
    I may be getting a laptop soon (as soon as someone is convinced that SI
    people need them). How about the same question on lap tops in hot cars?
    I dont expect to always need it on every call, so it may stay in the car
    sometime.

How similar is the plastic housing of a laptop to the plastic housing of
a video cassette? I've seen what a day in the hot sun in a closed car
can do to a T-120.

The trunk does not get as hot as the passenger compartment.
This is because it is not a green house.  The trunk will usually 
not get much more above ambient temperature.

    I beg to differ on the "trunk does not get as hot".  Maybe not as hot
    as the car interior, but still an enclosed space with no ventilation
    being heated through metal.  Certainly not ambient temperature!

    
    	And the 200� estimate sounds awfully high, unless you're talking
    	about 200 Kelvin.
    

    The heat and cold both impact battery life - negatively
    Some of the displays are adversely impacted as well

	Buy a cooler at the grocery store and toss them in there. It
	insulates both ways. Throw in a blue-ice pack for good measure.

	Put the CD's close to the gas (petrol) tank. That stays pretty
	cool. 

							mike

    .9 doesn't sound too cool of an idea to me...  :-)  Take a nice cold CD
    outa the cooler, pop it into the drive just in time for condensation to
    form a big pool of dew as the laser goes for the surface...  Nope, not
    this puppy.
    

re .6:

It's more likely to be at 200� F than 200 Kelvin unless you park at the
South Pole!

I'd say 200� F is about an absolute "worst case" maximum (black car with
black interior and real nice greenhouse windows (AMC Pacer?) parked in
Death Valley on the 4th of July at high noon)

    I think you can do some real measurements before feeling uncomfortable.
    Radio Shack sell's remote thermometers with min/max temp limits nicely 
    captured for ready reference. Few days a ago I got one for ~30.00.
    Using one of these see what the real temp are in the trunk. I agree
    with the earlier guess of  close to ambient temp. In any case these
    measurements will give you a real datum.

    Perhaps you can call some CD music manufacturers to tell you what is
    "normal" operating range for them. I some how feel that the temp you
    will be facing in south would still be within tolerable limits. But
    then again I am  not the one who is taking the risk!

Anil

    Just a thought, if drivers in your area use boot mounted auto change CD
    players without any problems then you have your answer.
    
    Guy               

    Yabbut Yabbut -- 
    
    Will you be able to BOOT with a CDROM that just emerged from the BOOT,
    is MY question.
    
    (only kidding, bitz is bitz, good point .13)
    

    re .5
    
    Unless the trunk has windows, I do not believe it will get as hot as
    the interior of the car.  What I remember being taught in college is
    this:  When radiant light passes through the glass in your car, it 
    is refracted and the wavelength (?) changes.  Once that happens, it 
    can not as easily go back through the window in the other direction, 
    thus the interior of the car can not cool itself through radiational 
    cooling.  The trunk would not have this problem.  It'll get hot in the
    trunk, but I don't think nearly as hot as the interior.
    
    Regardless of that, if anyone traveling with equipment or kits in their
    trunk would like to come of the PKO2 on a sunny day, I'd be happy to
    stick a thermocouple in their trunk to see just how hot it's getting in
    there.
    
    All of our equipment is supposed to survive (and is tested to) short 
    term storage conditions of -40 C (-40 F) to 66 C (151 F), with the 
    exception of some magnetic media.
    
    Regards,
    Steve Owen
    Thermal Engineering
    
          

    Not to change the subject completely, but what about 
    videotapes in a hot attic?  Will they be damaged?

    
    Re .15:
    
    Experience verifies this. After stting all day in hot, sunny parking
    lots, I've gotten blisters touching things in the passenger
    compartment, but I've never taken anything out of the trunk (including
    metal tools) that felt more than comfortably warm to the touch.
    
    An insulated cooler WITHOUT ICE OR EQUIVALENT sounds like a good
    insurance policy, but I doubt it's necessary.
    

It's obvious that most of these replies were posted by Yankees. If you live in
the north (where I am right now), summer is not very hot and you can usually
leave CDs in the trunk or under the seat of a car without trouble.

I'm from southeast Texas and used to travel extensively in the south central
region for volunteer work. I left a jacket where the sun could hit it through
the back window once, and the sun fade ruined the jacket. Paper can turn yellow
and brittle in less than a day with the same exposure. Ah, but the trunk has no
solar exposure, you say? My dry stick antiperspirant melted in the trunk between
El Paso and Las Cruces (40 miles) when it wasn't even 100 degrees outside. I
have seen Houston go for two weeks without dropping below 100 degrees Fahrenheit
even at night--concrete roads buckled so explosively near the Johnson Space
Center that chunks of road were thrown a block away. Nobody leaves anything
vulnerable to heat in a trunk or inside a parked car in that climate.

For that part of the country, the suggestion about a cooler with a sealed "blue
ice" pack in it is a good idea. It will keep the CDs near "normal room
temperature" for a long while--believe me, they WON'T be too cool. (I have used
"blue ice" wrapped in a towel to keep a computer functioning when the A/C went
out in Maryland during the summer.) Even just keeping them in a cooler with no
blue ice can help to even out the temperature swings.

Personally, I don't leave anything susceptible to heat in my vehicle all the
time. My music CDs are in a soft-sided 20-envelope zipper case (no jewel boxes).
Depending on weather and temperature, I can either put that under the seat of my
truck (being mindful of heat radiating from the parking lot) or put it on the
seat under layers of towels for insulation while the vehicle is parked. I choose
whichever location will be the least hot. I take all my CDs inside with me when
I go home.

The effects of heat exposure are not always evident immediately. If you just
occasionally leave your stuff in the trunk for a while in hot weather, it will
probably be okay as long as you pay attention to how you place your stuff and
whether it is an exceptionally blistering day. If you keep it there most of the
time, though, the heat will weaken it and unless you have easy summers
eventually you will have damage.

Bonnie D. Huval

Re: .16

The effect of heat on videotape and other magnetic media is a somewhat different
matter from the effect on CDs. Heat accelerates the rate at which print-through
(over-printing) occurs on magnetic tape, and the rate at which "weak spots go
bad" on a hard disk. Eventually, enough atoms will move to make these things
happen anyway--but heat energy makes more of them move sooner. That's why you're
supposed to archive magnetic tape loosely wound in a cool dry room.

Bonnie D. Huval

    Hmmm...If the topic is CD's and heat, isn't the phase change temp of 
    polycarbonate (which is what CD's are made of isn't it?) _way_ above
    200F?
    
    This ain't no vinyl LP .... ;)
    
    Any chemists out there?

re Note 4661.20 by KANATA::ZUTRAUEN:

>     Hmmm...If the topic is CD's and heat, isn't the phase change temp of 
>     polycarbonate (which is what CD's are made of isn't it?) _way_ above
>     200F?
  
        It's above the sea-level boiling point of water, but there
        may be other problems that occur before meltdown (e.g., do
        they warp? do the inks on the label do something bad? etc.).

        Bob

	from a non noting colleague but who  has a lot of exposure regarding 
        data CD-ROMS.
    
    From:	SHOGUN::TERRY        "PHIL TERRY, CD-ROM PROGRAMS, DTN: 264-2426" 17-JUN-1996 09:32:25.78
To:	SHOGUN::JAMBU_S
CC:	
Subj:	RE: your thoughts!

My thoughts and experiences.

There is a risk that the discs could warp.  CD's are significantly more 
sensitive to deflection (warp) than are the old LPs since the focal range of
the reader laser is short; when the deflection exceeds the range the CD is 
rendered useless.

I have not, however, encountered any CDs that have warped from being stored in
automobile trunks even during the summer months.  This non-damage experience 
is further supported by the many thousands of CD Audio Disc Changers that are
installed in trunks of the pricier cars on the market today.  I don't believe
Lexus or any of the others provide special cooling to the trunks (I don't 
believe they supply any cooling at all) and there has not been an outcry in 
the consumer market regarding expensive audio Cds rendered useless (expensive
because they would presumably warp in groups of 10).

So, although I believe the risk to be low, there still remains a risk that at
some temperature deflection may occur.

Phil
             

    Your car interior won't reach 200 degrees F unless it's on fire. The
    local TV stations here in Texas do stories every summer about the heat
    inside a car on a 100 degree day, as part of their annual "don't leave
    dogs or children in the car" spots. The highest temp I've ever seen
    them report was back when I lived in Dallas. On a bright, sunny 105
    degree day, the interior temp was 140 degrees.
    
    I'm sure that a black object, left in the direct sunlight, on the
    dashboard would reach a much higher temperature than the temperature of
    the air in the vehicle. This is why the cassette tapes melt. Keep them
    out of the direct sunlight and they won't melt.
    
    Harry
    

The polycarbonate that CDs are made of can withstand anything you'll get in a
car trunk.

				Steve

Since CDs are reasonably water resistant and we can assume a car trunk will
never reach 212�F, the following may answer the question.

Obtain one CD that you don't care if you ever read/boot from/listen to again.
Boil some water in a pan large enough to hold the CD.  When water is boiling
place CD in the water and simmer for a few minutes.  Fish it out with a fork.
If it's visibly warped it cannot survive that temperature.  If not warped or
otherwise damaged, try to read/play it.  If you still can you can be assured
the CD will survive your car's trunk.

-Mike

    OK, so we are pretty sure on CDs.
    
    Now how about laptop computers? LCD screens? disk drives?
    
    

    re .26
    
    Should survive to 66 Deg C (151 Deg F).  That's our short term storage
    spec (short term is defined as being 60 days or less) on almost all
    products.  Some magnetic media may have slighly lower temperature
    limits.
    
    We have tested laptops, LCD screens, disk drives, and a huge variety of
    other products to those limits.
    
    The full test spec is listed in DEC-STD-102 section 2.2.
    
    Regards,
    
    Steve Owen
    TCS/Technology
    Environmental Engineering
    

You could always boil the laptop to find out....


(Ohhh, would I love to see that ;^))

    re: .28
    
    I'll bet there are plenty of unused 325Ps available for testing.
    
    Bob

>           <<< Note 4661.25 by EVMS::MORONEY "It's alive! Alive!" >>>
>                            -< Poached CD anyone? >-
>
>Since CDs are reasonably water resistant and we can assume a car trunk will
>never reach 212�F, the following may answer the question.
>
>Obtain one CD that you don't care if you ever read/boot from/listen to again.
>Boil some water in a pan large enough to hold the CD.  When water is boiling
>place CD in the water and simmer for a few minutes.  Fish it out with a fork.
>If it's visibly warped it cannot survive that temperature.  If not warped or
>otherwise damaged, try to read/play it.  If you still can you can be assured
>the CD will survive your car's trunk.

I did this experiment last night.
I boiled a pan of water and dropped a CD-ROM that I fished out of the trash
here.
The disc stayed stiff in the water, and was not bendable when I fished it out.
Physically, it survived just fine - no warp, no delamination.
However, it was not a format that I could read before, so I couldn't verify 
that the data survived the trip.  It was still recognized as an unreadable 
and unwriteable (locked) volume on my system, as opposed to not a disc at all, 
so there's hope that the data would survive such treatment.

Anybody want to take this as introductory to the next step and try a disc they
know they can read?

- tom]

> Anybody want to take this as introductory to the next step
> and try a disc they know they can read?

  Surely someone has an AOL CD-ROM (or ten) sitting around
  just begging to be boiled! :-)  After all, one can't re-use
  'em like we used to re-use the AOL diskettes!

                                   Atlant

Yeah, I have at least one I can dedicate to the cause...  I'll try this
tonight.

			Steve

    Ok - I took a CD-ROM I was about to trash (an old beta of some software
    I'm testing) and kept it in boiling (full rolling) water for 10
    minutes (with the cover on the pot - slightly increasing the boiling
    point and making sure that the top of the CD (it floats) got hot too.)
    Fished it out, let it cool off (almost instantly), wiped the water off. 
    No physical damage evident.  Popped it in the CD-ROM drive - worked
    perfectlty.
    
    From this, I would expect CDs to survive unscathed in a car trunk,
    though one might also want to test whatever they're being carried in.
    
    			Steve

    Well, THAT oughta earn ya some sort of communal AttaBoy, Steve.  
    
    Therefore by the ~0 Powers vested in me, I propose that ye be 
    grawnted full Membership in the 
    
    Ancient ROMan Order of the Caloric Disk, with Oakleaf clusters.
    
    :-)
    

    
    	Attaboy, Steve.  8^)
    
    	But please keep in mind that this does NOT mean that you can
    	leave a CD on your dashboard in direct sunlight, because the
    	temperature outside is ONLY 100� and the CD is capable of
    	surviving 212� in a pot of water.
    

Sounds like it's time for Steve to leave the CD on his dash in direct 
sunlight...

Given that a CD is reflective, leaving it on the dashboard shouldn't itself be
a problem, but I'd worry about binders and solvents leaching from the 
dashboard material that might attack the label layer.

I must admit I didn't do a before-and-after taste test....  I wonder what
Martha Stewart has to say about this?

					Steve

    
    I like this ground research. There ought to be a prize to the one who
    accidentaly destroys a CD in the most spectacular way, e.g.,
    
    Put it in the washing machine.
    Put it in a martini with a couple of olives and stir well.
    Give it to the dog to chew on.
    Cover it with creamed mushrooms and bake it 30 minutes.
    
    /�.
    
    

    
    	Deb, would you mind trying the martini trick for us?  I'm sure
    	you have a bunch of Gilbert O'Sullivan CD's that are perfect
    	candidates for this sort of testing.
    
    	Washing machine, eh?  Hmmm, I'll give it some thought and I
    	might even try it.
    

	It's a scary thought that someone remastered a Gilbert O'Sullivan 
	onto CD. Some people really have too much time on their hands.

	Of course, now I can't get his songs out of my head. I hate you
	Shaun.

	:)

							mike

    
         ,.',.'
    8^pPpPPp,.','.
          ,'.,.'
    
    Loan me one of those trashy heavy metal "music" disks, and I'll put it
    in my martini.
    

Well, the most spectacular way to trash a CD, of course, would have to be
putting one in an oven.  Microwave, of course! ;-]
(Don't try this at home unless you're already buying a new microwave!)

>    Put it in a martini with a couple of olives and stir well.
    

    Yabbut if you use regular olives then it's not a fair test -- the
    olives' pits are SURE to interfere with the later reading of the
    CD-ROM's.
    
    Really!!
    

re .39:
>>    Give it to the dog to chew on.

our dog likes to chew on plastic and likes to catch flying objects.
he refused the AOL CD even when still wrapped in plastic and thrown
as a frisbee.

    re: Martini thread...
    
    Shaken, not stirred.

    When GE invented LEXAN plastic in the 1960's they sent out an ash tray
    as a sample, with a prize offered for the most interesting way to break
    it. Of course the engineering students in my school rushed out to break
    the thing, with all manner of mechanical devices. As I recall, no one
    broke it, but one guy made a hell of a dent in the frame of a steel door
    trying.
    
    Id guess a CD would be eaiser to break.

Ron:

  You probably know this, but CDs are made of polycarbonate plastic.
  That's the generic name; LEXAN is GE's trademark for this same plastic.
  I believe Europeans may know it (or a very similar plastic) as Merlon.

                                   Atlant

    > As I recall, no one broke it, but one guy made a hell of a dent in the
    > frame of a steel door trying.
    
    Dip it in liquid nitrogen then drop it on the floor.
    
                                    August

RE: .50

	I hear that works great for breaking mice into small chunks.

							mike

    
    	RE: Mike
    
    	Why not just chew your food more thoroughly before trying to
    	swallow it?
    

.39:
> I like this ground research. There ought to be a prize to the one who
> accidentaly destroys a CD in the most spectacular way.

	Well, it was not accidentaly destroyed but it was accidentaly
	spectacular:

		Try folding one in half...  I did.

	After bending about 160 degrees (bend radius was about 3/4")
	the disk just went "BANG!" and sharp little pieces flew off 
	in many directions.

.43:
> Well, the most spectacular way to trash a CD, of course, would have to be
> putting one in an oven.  Microwave, of course! ;-]
> (Don't try this at home unless you're already buying a new microwave!)

	I've done this several times, both at home and at work and
	I have not lost an oven yet.  It only takes a couple seconds
	to get 99% of the effect.  Further cooking only produces
	tiny sparks and some chared spots.

	Cook with paint side up or you'll leave stains on the floor
	of the microwave.  I tried a stack of three and the effect
	is not quite as pronounced.

    -.1
    
    Remind me not to go to dinner at John's house, especially if it's
    microwaveable.

    
    Well here's my CDROM torture test:
    
    I gave a CDROM (Linux TS-11 archive, Fall 94) to my 7 month old daughter
    to chew on for about 10 minutes.  She deposited baby drool (she is
    teething) snots (she has a cold) and a little puke on the disk along
    with many small finger prints.  After waiting a few seconds for it
    to dry I dabbed off a couple of big blobs for the sake of the CD lens
    and popped it into my PC.  It read fine.

I believe there can be no greater evidence than this note to explain the
phrase "it's a guy thing", Dave Barry would be proud and we women remain
mystified as always. :*) liesl 

For those not in the know, Dave Barry says that when a "man" hears about someone
throwing a sofa off the top of a building, he says something like "what a waste
of valuable resources."  When a "guy" hears about it, he says, "Wow, really?  A
sofa?  I wish *I* had thought of that!"  I don't think Dave has said what a
woman would say.

Burns

    ... I recall them having established some new unit of volume being "The
    volume contained in the dent in a standard macadam sidewalk caused by
    dropping a grand piano off of Baker House."
    
    ... an exact reference by someone with the time to surf it up will
    undoubtedly follow.
    

I saw an upright piano droped off of Baker House, but never a grand piano.
I've heard of Smoots but never this unit of measure.

Jim

Re: -2

It's a "Bruno".