Minimum Humidity for long term storage of computer equipment?

[Bennett Price]

I wonder if the bag should be an electro-static bag, rather than just
plastic of some sort. That said, I've no idea whether truly air-tight
electro-static bags are available (or necessary).

 

[Zak]

Do *NOT* use CO2 instead on Nitrogen! Any residual moisture will react
with the CO2 and form carbolic acid.

I would also worry about your "vaccuum sealing" plastic. Will it outgass
and stain the surface? Will it stick after many years? At a bare minimum
I would wrap the items in archival-quality acid-free tissue paper before
shrinking the plastic around them. Better yet would be to put the tissue-
wrapped item inside a polyplopylene storage container (tupperware style).
Do it right and it will also protect against moderate banging around.

Be aware that this newgroup contains a mix of wise/experienced people
and morons who will lead you astray. Talk with someone who stores
antique books. The techniques that protect those will work on your
electronic items, with the exception of humidity; I think they like
more than what is best for your application.

Mind you that PVC can give off HCl gas over time. This is a self
catalyzing reaction, but HCl is probably also bad for lots of other
things. Are we sure that sealing is the best idea here?


Thomas

 

[[email protected]]

I bought some antique handheld computers. I want to keep them in pristine
condition for a very long time, fifty years or more. I want to know the ideal
environmental conditions to store these computers. I am probably going to store
these in a bank vault. I can greatly reduce the relative humidity using a
commercial desiccant such as drierite.

I think you're going about this the wrong way. Your task is not to
preserve a mysterious "artifact" for posterity but to be able to keep
at least one "tool" in working order for the next fifty years.

Tools are not mysterious artifacts, they are engineered systems made of
generally understandable components.

Don't try to preserve them against time, instead try to preserve the
functionality in a maintainable way. Take one apart. Catalog what's
in it. Consider the failure modes of each component. Are there parts
that can be readily replaced today which you should stockpile? Are
there abstract parts, like firmware, which could be copied out into a
variety of other storage media? Look for a small backup battery, and
if found decide if you can remove it (and still be able to
re-initialize the system when it's replaced) or if you must keep it but
monitor for leakage.

 

[Peter Olcott]

I think you're going about this the wrong way. Your task is not to
preserve a mysterious "artifact" for posterity but to be able to keep
at least one "tool" in working order for the next fifty years.

Tools are not mysterious artifacts, they are engineered systems made of
generally understandable components.

Don't try to preserve them against time, instead try to preserve the
functionality in a maintainable way. Take one apart. Catalog what's
in it. Consider the failure modes of each component. Are there parts
that can be readily replaced today which you should stockpile? Are
there abstract parts, like firmware, which could be copied out into a
variety of other storage media? Look for a small backup battery, and
if found decide if you can remove it (and still be able to
re-initialize the system when it's replaced) or if you must keep it but
monitor for leakage.

These are HP 200LX MSDOS compatible 80186 processors. They were made in 1996 and
discontinued. Parts are available right now, as third party service. Neither of
these may be available in as little as ten years. I had them upgraded to
doublespeed so that they run all the old MSDOS software 1/3 faster than an
original IBM AT. I bought one of these and three spares. There will not be any
qualified technicians ten years from now, so there is no sense stocking up on
spare parts. I will be storing the three spares.

 

[[email protected]]

I saw a sign outside a tyre place advertising nitrogen, go there with a few
dozen baloons, or your spare tyre...



CoCl2 is highly toxic. are you sure ?

Could be CaCl2 (calcium chloride) dessicant... it's pretty cheap - I
got some from Target about 10 years ago. I think it's a byproduct from
making something else that's more useful...

There's silica gel too, zeolites as dessicant...

the air is 75% nitrogen. 100% nitrogen is unlikely to react in a way that
75% doesn't

Isn't air closer to 78% nitrogen?

 

[Peter Olcott]

Could be CaCl2 (calcium chloride) dessicant... it's pretty cheap - I

97% CaSO4 Dessicant
3% CoCl2 Cobolt Blue Indicator

 

[Rich Grise]

It is nothing like a prefect vacuum, I am only using a foodsaver meat packaging
machine. The idea is to make the package fit tightly, removing all the excess
air


What about reducing the relative humidity to zero?


I can't go to this extreme, what is the next cheaper option?

What extreme? You go down to the weld shop, get a tank of nitrogen, and
while you're sucking the air out of one end of the bag, you're purging
it from the other with dry nitrogen. Then, turn off the vacuum, let the
bag fill a little bit with N2, turn it off, then hand-squash the N2 out
and seal it. It would do no harm to toss in a bag of silica gel.

You get the regulator and rubber tube at the weld shop as well - You'd
have to pay to rent them, but I don't think the cost of the nitrogen
would be prohibitive or anything.

Good Luck!
Rich

 

[Rich Grise]

How could this be packaged to retain the nitrogen / co2 ?

Triple ziploc bags?

Cheers!
Rich

 

[Rich Grise]

How can I get nitrogen least expensively?

http://www.google.com/search?hl=en&q="nitrogen+gas"

Or look in the yellow pages under "gases" and make some calls.

Good Luck!
Rich

 

[Peter Olcott]

What extreme? You go down to the weld shop, get a tank of nitrogen, and
while you're sucking the air out of one end of the bag, you're purging
it from the other with dry nitrogen. Then, turn off the vacuum, let the
bag fill a little bit with N2, turn it off, then hand-squash the N2 out
and seal it. It would do no harm to toss in a bag of silica gel.

You get the regulator and rubber tube at the weld shop as well - You'd
have to pay to rent them, but I don't think the cost of the nitrogen
would be prohibitive or anything.

Good Luck!
Rich

No its the cost of renting or buying the tank. The nitrogen itself only costs
$14.00 for 24 CF.

 

[Peter Olcott]

Triple ziploc bags?

Cheers!
Rich

I can use foodsaver hermetically sealed bags they are 2 mil which seems to be at
least double the ziploc thickness. If triple ziploc bags are enough, then one
foodsaver bar should be enough.

 

[Lostgallifreyan]

No its the cost of renting or buying the tank. The nitrogen itself
only costs $14.00 for 24 CF.

Welder's supplies of nitrogen can come in little tanks like aerosol cans,
it's just compressed heavily, not to the point of being liquid. There's
still more than enough in a £10 can though. Why agonise over it? If
you've ever justified the spend on a can of spray paint, this will be no
problem.

 

[James Waldby]

Triple ziploc bags?

Tripling up on ziploc's could get pretty expensive,
don't you think? Probably better to go with something
where you only need one layer, like the stainless steel
foil bags at (all on one line)
http://www.nolansupply.com/bysubcat...ainless+Steel+Foil+Bags&type=False&specs=True

-jiw

 

[Peter Olcott]

Welder's supplies of nitrogen can come in little tanks like aerosol cans,
it's just compressed heavily, not to the point of being liquid. There's
still more than enough in a £10 can though. Why agonise over it? If
you've ever justified the spend on a can of spray paint, this will be no
problem.

If I can do it this way, then yes. If I can only do it by buying a one time use
air tank for $185, then no. The one welder's supply company that I called
charged $130 for their smallest tank.

 

[Bill Shymanski]

Is there a minimum level of relative humidity, below which computer equipment is
damaged?

I bought some antique handheld computers. I want to keep them in pristine
condition for a very long time, fifty years or more. I want to know the ideal
environmental conditions to store these computers. I am probably going to store
these in a bank vault. I can greatly reduce the relative humidity using a
commercial desiccant such as drierite.

Thanks for your help.

Humidity is the least of your worries. In 50 years every electrolytic
capacitor in those machines will
have turned to mush - the machines will not be usuable. I don't know
what the storage life of a
EPROM or flash memory is, but I doubt that is 50 years, either. The
commercial life of these machines was measured in months - they weren't
really designed for long-term storage. Low temperature might help -
keep them down at the low end of the commercial range, toward 0 C, to
slow down the bit-rot and electrolytic
decay.

Bill

 

[Lostgallifreyan]

If I can do it this way, then yes. If I can only do it by buying a one
time use air tank for $185, then no. The one welder's supply company
that I called charged $130 for their smallest tank.

I've just checked to see that Clarke welders are sold in the UK and the US;
not sure where they originate.

They sell a lot of stuff at low prices, including argon in small tanks that
in 1999/2000 were being sold in the UK for £9.99 in Maplin Electronics.

Argon is probably a better choice that nitrogen, and although it's more
expensive to extract from air, is probably cheaper to buy in small amounts,
given the rise of small scale DIY welding.

Just make sure you get the argon, not the Ar/CO2 mix..

It seems it's stupidly difficult to find a DIY welder seller with the sense
to realise you need to keep customers happy by selling spare such as wire
and gasses, but here's one:

http://www.machinemart.co.uk/search.asp?q=argon

That's a lead, but it will take some work to find a local supplier. Maybe
best to ask in local DIY and auto shops. As the price is very low,
virtually unchanged in 6 years, you should get lucky.

 

[[email protected]]

These are HP 200LX MSDOS compatible 80186 processors. They were made in 1996 and
discontinued.

There will not be any
qualified technicians ten years from now, so there is no sense stocking up on
spare parts.

Where did you get that idea?

Outrageous that it is, it does at least explain why your approach is to
treat these as mysterious artifacts...

 

[Peter Olcott]

Humidity is the least of your worries. In 50 years every electrolytic
capacitor in those machines will
have turned to mush - the machines will not be usuable. I don't know

What is the range of the estimated lifespan for the best capacitors?

what the storage life of a
EPROM or flash memory is, but I doubt that is 50 years, either. The

Flash seems to have data retention between 10 to 40 years.
They don't have to retain any data besides their ROM. I would
estimate that they would still be usable (if reprogrammed) much longer than
this.

 

[Peter Olcott]

Where did you get that idea?

There is only one company left that will work on them, and they will probably be
out of business when the owner retires.

 

[Peter Olcott]

I've just checked to see that Clarke welders are sold in the UK and the US;
not sure where they originate.

They sell a lot of stuff at low prices, including argon in small tanks that
in 1999/2000 were being sold in the UK for £9.99 in Maplin Electronics.

Argon is probably a better choice that nitrogen, and although it's more
expensive to extract from air, is probably cheaper to buy in small amounts,
given the rise of small scale DIY welding.

Just make sure you get the argon, not the Ar/CO2 mix..

It looks like you are right on this. The U.S. constitution is stored in Argon.