On 12/4/2013 8:00 PM, Warren Young wrote: > As my measurement data in the post I just sent hints, there are serious practical problems -- aside from the direct economic ones -- that restrict the utility of such high-purity alcohols. There's probably no point using it outside a cleanroom. Dust on the glassware will wreck the purity rating otherwise. alcohol much higher than ~ 90% is hydroscopic and will absorb humidity from the air until it reaches the azeotriopic place where its happy. seriously, its a heat spreader, youre gonna be spreading silicone paste on. any old alcohol will work fine, don't use /too/ much, just dampen the wipes with it, repeat with clean wipes til the surface is clean, air dry in a few seconds, then apply fresh arctic silver v or whatever. frankly, for servers, I prefer using the plain white classic thermal silicone stuff, its less conductive, and servers usually have plenty of air and cooling, you're not overclocking them. -- john r pierce 37N 122W somewhere on the middle of the left coast