heat spreader splice, AS II epoxy, and homemade water block question???

[dew042]

I built a water block from a 2 3/4" copper pipe endcap and some lexan.... but then i realized some things: first the walls of the waterblock are like 1/16" and they are most likley the lower grade of copper with less themal conductivity since its for plumbling applications.

the thing that bothers me is that the thin walls and lower quality copper mean that the heat won't spread out as well to take advantage of the large amount of surface area inside my block.

my original thought was to buy a round 2 3/4" piece of 3/8" pure copper (already bought) and then lap it and use Artic Silver epoxy to connect the copper round piece as a heat spreader...

Then i realized that copper has a thermal conductivity of 384 W/m K and Artic Silver runs around 8 W/m K... Is my idea of splicing on the extra 'copper heat spreader' with the AS epoxy going help of hinder my cooling abilities???

Someone suggested thermal solder, but I doubt the heat needed would be good for the counter sunk lexan (1/4" in ) that is already attached with clear epoxy..... Any thoughts or ideas would be greatly appreciated....

Thanks.
dew.

[Hoot]

You are right in being concerned about adding another thermal barrier. You almost have to approach these kinds of experiments on a case-by-case basis. I would try the heat spreader and see. There are few guarantees in overclocking. Just lap the two mating surfaces, put the AS to them and see what happens. Thermal solder is almost an oxymoron, unless you are talking Silver Soldering. That takes a much higher temperature than conventional Lead/Tin or Tin/Silver solders. Still, the soft solders have better thermal conductivity than AS. I get the most enjoyment in experimenting. Anyone can implement a known process, but there is a special satisfaction in trying something unknown. Sure, it's a bummer if it doesn't pan out. I know this from many failed "bright ideas", but even then, I learned something new from every one.

Hoot

[dew042]

thanks for the input hoot....

i think i figured out a solution....

in the bottom of the copper cap I am going to drill a 2" hole with a hole saw and then epoxy or solder the heat spreader on.... so most of the heat spreader will be directly cooled by the water and the AS epoxy won't be the bottleneck anymore....

this of course after i tried to AS epoxy it to the bottom and it started sparking and blew up (that part i made up.) It was not good to say the least... the contact was poor and it would have negated any benefit of WC....

thanks.

[surlyjoe]

A/S epoxy is NOT waterproof!!

[dew042]

yeah.... i do realize that... i was just slow last night....

i think i learned it off of your site in fact surlyjoe....

thanks.