[CentOS] died again

Wed Dec 4 20:22:24 UTC 2013
Michael Hennebry <hennebry at web.cs.ndsu.nodak.edu>

On Wed, 4 Dec 2013, Warren Young wrote:

> On 12/3/2013 22:09, Michael Hennebry wrote:

>> They mention "high-purity isopropyl alcohol".
>> The highest purity I've ever seen is 70%.

> Bottom line: 70% is too impure for this task.
> I hesitate to use even 90% for this.  The last time I used 90% isopropyl

> While looking for up-to-date info on Radio Shack's web site, I came
> across this relevant item: http://goo.gl/nLzub7  At $11 for a couple of
> tiny bottles, both of which you have to use together, it's another 2-3x
> more expensive than tape head cleaner.  Plus, if you look into the MSDS,
> the first part is acidic, so you must need the second pass to neutralize
> what's left behind on the first pass.  Sounds like a bad plan to me.

For me, the bottom line is how much it will cost
to clean *one* CPU/heat spreader combination.
It looks like the answer is going to be
a bottle I saw at Radio Shack for $11.

> Everclear 190 proof should also work for this.  At $20 per fifth, it
> comes out under $1/oz, so cheaper than the RS fluids, but still more
> expensive than the box o' isopropyl.  Some households will find it a
> more widely useful commodity, so there's that. :)

I didn't use everclear when I did drink.

> For what it's worth, you can get even purer isopropyl alcohol intended
> for lab use.  Prices I found online ranged from about $60-100 per liter,
> or $2-3/oz, shipped.  100% is possible if you synthesize it, at even
> higher cost.

I'm not sure what you mean by synthesize in this context.
Alternating freeze- and evaporative-distillation
can get you anything less than 100%.
That said, 'tain't necessarily economical.
At some point, I suspect getting rid of the water through
electrolysis or some other chemistry might be better.

Michael   hennebry at web.cs.ndsu.NoDak.edu
"SCSI is NOT magic. There are *fundamental technical
reasons* why it is necessary to sacrifice a young
goat to your SCSI chain now and then."   --   John Woods