Forgot thermal paste

[Paul]

It looks different in the US as 100% Isopropyl Alcohol is easily available
& even Safeway carries their brand with 99% Isopropyl in the aisle shelves;
the bottles do have a warning that it is flammable & to keep away from
heat, etc. 100% Isopropyl Alcohol is also preferable for cleaning the
stylus on a phono cartridge for those who did care about their stereo
equipment & vynl records.

http://en.wikipedia.org/wiki/Isopropanol

One MSDS I looked at, warned bout the possibility of forming peroxides. An
Agilent procedure, made use of nitrogen gas as a passive gas above the
liquid. It implies that perhaps the more concentrated form is more likely
to form peroxides.

While this involved some chemistry, it is an example of what can happen.

http://www.bnl.gov/esh/shsd/programs/Program_Area_Chemicals_Hazard_Alert_Isopropanol.asp

And here:

http://ehs.ucdavis.edu/ftpd/sftynet/sn_23.pdf

"Alcohol/water solutions do not form high concentrations of peroxides."

Which suggests to me, the reason 99% or 100% solution is not a good choice,
is the potential for peroxide formation. The last doc claims it is only
an issue if you boiled a quantity of isopropanol to dryness, which would
concentrate the peroxide and raise it concentration, at the point the
beaker is approaching dryness.

I'll stick with 70%, thanks

Paul

 

[student]

http://en.wikipedia.org/wiki/Isopropanol

One MSDS I looked at, warned bout the possibility of forming peroxides. An
Agilent procedure, made use of nitrogen gas as a passive gas above the
liquid. It implies that perhaps the more concentrated form is more likely
to form peroxides.

While this involved some chemistry, it is an example of what can happen.

http://www.bnl.gov/esh/shsd/programs/Program_Area_Chemicals_Hazard_Alert_Isopropanol.asp

And here:

http://ehs.ucdavis.edu/ftpd/sftynet/sn_23.pdf

"Alcohol/water solutions do not form high concentrations of peroxides."

Which suggests to me, the reason 99% or 100% solution is not a good choice,
is the potential for peroxide formation. The last doc claims it is only
an issue if you boiled a quantity of isopropanol to dryness, which would
concentrate the peroxide and raise it concentration, at the point the
beaker is approaching dryness.

I'll stick with 70%, thanks

Paul

Thanks for the info & websites, tho I don't find the wikipedia to be that
accurate on what I've looked up.

As I no longer have phono records, the Isopropyl is for disinfectant as
from scratching because of "neighbors"'s dogs & their fleas. Will switch
since the stuff is very cheap.

 

[jinxy]

Thanks for the info & websites, tho I don't find the wikipedia to be that
accurate on what I've looked up.

As I no longer have phono records, the Isopropyl is for disinfectant as
from scratching because of "neighbors"'s dogs & their fleas. Will switch
since the stuff is very cheap.- Hide quoted text -

- Show quoted text -

If the dogs have fleas, simply insert a lead pill behind their ears.
No more scratching !

 

[Jon Danniken]

One MSDS I looked at, warned bout the possibility of forming peroxides. An
Agilent procedure, made use of nitrogen gas as a passive gas above the
liquid. It implies that perhaps the more concentrated form is more likely
to form peroxides.

While this involved some chemistry, it is an example of what can happen.

http://www.bnl.gov/esh/shsd/programs/Program_Area_Chemicals_Hazard_Alert_Isopropanol.asp

And here:

http://ehs.ucdavis.edu/ftpd/sftynet/sn_23.pdf

"Alcohol/water solutions do not form high concentrations of peroxides."

Which suggests to me, the reason 99% or 100% solution is not a good
choice,
is the potential for peroxide formation. The last doc claims it is only
an issue if you boiled a quantity of isopropanol to dryness, which would
concentrate the peroxide and raise it concentration, at the point the
beaker is approaching dryness.

I'll stick with 70%, thanks

Paul, with all due respect, those two articles cite the formation of
peroxides when using IPA in specific situations as a laboratory solvent, not
as a cleaning agent. For the typical home user, using the chemical for
cleaning, such a concern is beyond negligible.

Jon

 

[Paul]

Paul, with all due respect, those two articles cite the formation of
peroxides when using IPA in specific situations as a laboratory solvent, not
as a cleaning agent. For the typical home user, using the chemical for
cleaning, such a concern is beyond negligible.

Jon

I was looking for a reason why I can only find 70% on my drugstore shelf.
It is cheaper to make, and that could well be the number one reason.

I agree that it is not an issue for typical usage. You are more likely to
set it on fire and burn yourself, than anything else.

What got me interested, is this procedure, for transferring isopropyl to
individual bottles. They do seem to be paranoid about air coming in
contact with it. Maybe it has something to do with the intended application
for the tiny bottles of chemical. It doesn't state what they are using it
for (washing, chem reaction etc).

http://www.chem.agilent.com/cag/bsp/proseq/sops/mfg/G2284.htm

Paul

 

[Jon Danniken]

I was looking for a reason why I can only find 70% on my drugstore shelf.
It is cheaper to make, and that could well be the number one reason.

Aye, I do not know the typical method for creating IPA, but if part of the
procedure involves distillation from a diluted solution, that would make
sense. BTW: Freddies sells the 99% stuff for a buck fifty a pint.

I agree that it is not an issue for typical usage. You are more likely to
set it on fire and burn yourself, than anything else.

True, especially since the most common usage (diabetic site prep) only
requires the 70% solution.

What got me interested, is this procedure, for transferring isopropyl to
individual bottles. They do seem to be paranoid about air coming in
contact with it. Maybe it has something to do with the intended
application
for the tiny bottles of chemical. It doesn't state what they are using it
for (washing, chem reaction etc).

http://www.chem.agilent.com/cag/bsp/proseq/sops/mfg/G2284.htm

It looks like they are using it in chromatography, (HPLC), which could
require an annhydrous solution. IPA (and other alcohols) will absorb
moisture from the air, which could be the reason they seem to be so strict
about it's handling and storage requirements.

Jon

 

[JClark]

Hello,
I recently put together a computer but forgot to put the thermal paste
on the CPU before installing the heatsink/fan. Should I take it down
and do it? Is it that important?
I think it would involve buying a new heatsink rack, because I've
never been able to get those push-pins out from above. Or should I
take out the MB from the case and push them out from below?
Many thanks.

Jack

I appreciate all the replies. I guess the concensus is that I should
take it apart and apply the thermal paste. I did buy a new heatsink in
case I need it.

Many thanks again.

Jack