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.