water cooling v. fan\heatsink - Page 2

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Re: water cooling v. fan\heatsink

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Use just *one* pipe; and a wick in the same pipe to bring the liquid
back.  A lot more reliable and simpler.

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Get a hunk of soft copper pipe and three standard "all copper"

Cut all the fins and such off one of the three heatsinks, leaving only
the copper base and mounting-block where it mounts to the CPU.  Holding
the heatsink in a vice and using a hacksaw works OK.  Using a metal
band-saw is easier, if you have one.

Feed a soft cotton "wick" from one end of the copper tube to the other.
A wick made from about two or three layers of old cotton T-Shirt sewn
together and then cut to about 3/8" width will do fine.  When in place,
it should fill about 1/4 to 1/3 of the available space in the tube
without blocking airflow.  (You should be able to blow easily through
the tube, almost as if the wick wasn't there.)

Bend the copper tubing until it runs from where the CPU (and copper
block are to where you want the radiator (made from the other two
heatsinks) will be located.  At the beginning, leave an extra inch or
two of overlap *past* where it fits over both sets of heatsinks.  You'll
be mounting the tube full-length on each one.

Flatten the end of the tubing where the CPU block is to be attached with
a hammer.  Not enough to close it off or even pinch tightly; but enough
to make a good and comparatively wide connection to that block.  If
necessary, buy a slightly larger diameter pipe, solder that to the end,
and flatten the larger pipe.  Pinch off the end with a cutting-pliars.

Flatten the other end of the pipe in a similar manner; but do *not*
pinch off the end.  When you flatten the pipe-ends, you should keep in
mind the orientation of the CPU-block one end will be mounted on, and
the other end that will have the two other heat-sinks mounted on it.

Using a plumber's torch, flux, and plumbing solder, solder the flattened
end to the CPU block; and seal the pinched end at the same time with the
same solder.  (Remember to *clean* the copper with sandpaper,
emery-cloth, or steel-wool before trying to solder it.)

Do the same thing at the other end; only this time solder the pads of
the two large finned-devices one on each side of the flattened tube.

At this time take a little extra time to plan and mount attachments to
the device for where it will fit on your computer system.  Solder them
on too.

Fill the tube (from the sink-end, which you were supposed to leave open)
with isopropyl alcohol.  Get it from your drugstore.  Or better-yet, buy
it as "ISO-Heat" or similar gasoline-antifreeze.

Now find a *big* pot that will almost contain your new
heatpipe/heatsink.  Fill the pot up with water, so that *with the pipe
inside the pot* it almost but not quite covers the open end of the

Take the heatpipe out of the pot.
dump out the (possibly contaminated) liquid inside into a measuring
container.  Take careful note of how much liquid you removed.  (Some
will remain inside, wetting the wick.)

Bring the water in the pot to a full boil.
Turn it down to "simmer".
Pour fresh isopropyl alcohol into the heatsink ... about 1/3 the amount
you dumped out and measured.

Using tongs, *carefully* put your heatsink loaded with alcohol into the
(just barely) boiling pot.  Don't let water get in to mix with the
alcohol.  Watch *closely*; and you'll soon see it begin to express gas
and perhaps even steam.  After about ten seconds of this, pull the
heatpipe/heatsink combo out of the pot with tongs and *quickly* solder
the open end shut before it stops steaming.


Perhaps a *tiny* bit more complicated than designing and building a
water-cooled/pumped device; but not (to my notion anyway) seriously so.

Yes, fancy commercial heat-pipes use expensive metal foam or sintered
material as wicks ... But plain old cotton works fine too.  You aren't
planning on the thing even getting up to boiling temperatures.  That,
after all, is how early experimental heat-pipes were built.

Yes, it's a *lot* more expensive than just buying a commercial heatsink
with fan.  But it gets the heat *ouside* the case without relying on
pumps, fans, or other power-consuming gadgets.  The outside heatsink can
then be mounted to use normal air-convection to cool it.

Of course, it will probably be just as cheap, or possibly even cheaper,
not to mention better built, to buy a *commercial* heat-pipe/heatsink
combo made to fit your motherboard.  They, doing it by hundreds, will do
it much cheaper than you ever could; and still sell it to you at about
the same price or less than you could build your own.

There's all these:

But they all seem to be designed to just be a bigger and more efficient
heatsink; not one going external.

Here's a passive set that comes with the motherboard ... but only for
the chipset; not the CPU itself.

Here's somebody that supplies a whole passive "silent" CPU system using

Hmmm ...
It seems that most people using heatpipes for CPU cooling use them to
enhance the efficiency of heatsinks with fans, *not* to take the heat
outside the case and disipate it there.  I presume the main reason being
the varied differences in cases and motherboards.  Thus water-cooled
designs with flexible tubing working better for such uses; allowing far
more flexibility in where and how they are mounted.

The few that *do* use heatpipes for completely passive systems, do so
for their own specially designed cases in which the heatsink *is* the

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