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At a local workshop we have a portable and old heating device where the heat generator's housing reaches around 180°C during operation. The original external aluminum radiator with a fan attached to it have small dissipation capabilities. The integrated heat protection often trips that sometimes breaks our work waiting it to cool down a bit. We decided to give it a go and attach two old CPU tower-type coolers, each has 4 heat pipes to it.

The idea is to remove their pipes from their bases, straighten the pipes (slowly) and cross them so the fins are in the four directions and in one plane.

The problem is now clear; Which one is better for cross-connecting the pipes, soldering or brazing, Which will hold against the 180°C?

Note: That this will be a pure spare-time project before the better device arrives

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  • It is unclear what it is exactly you are doing or trying to achieve. – Alaska Man Jan 13 at 21:19
  • To connect crosswise the copper pipes of two CPU coolers and the connection to hold against a high temperature – 1000Gbps Jan 13 at 21:21
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    cpu cooler pipes contain refrigerant of some kind ... be very careful when bending them – jsotola Jan 13 at 21:27
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    This is more industrial fabrication than home improvement, but brazing is considered the more robust approach. It's required for gas piping, for example. – isherwood Jan 13 at 21:33
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    Also, a quick search reveals that plumbing solder melts at about 182 C, so that seems relevant, @whatsisname. :) – isherwood Jan 13 at 21:35
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For strength and durability Brazing ,hands down, is the better choice. Copper brazing rods have a hire melting point than the tin solder used for plumbing. I believe the copper rods need something like 1850 F melting point.

Your problem may be that even though the CPU heat pipes are copper they are most likely very thin so if you apply 1800+ degrees of heat it will surely disintegrate.

Consider that by mechanically attaching the two metals with a copper wire will yield similar results.

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CPU heat pipes are filled with low-boiling chemicals, such as water or alcohol. At 180°, likely above the critical temperature of the coolant, there would only be supercritical fluid in the tubes, and the heat pipes would no longer function. Further, they might burst, whether soldered or brazed.

Why not just add an auxiliary fan -- perhaps a squirrel-cage (centrifugal) blower, if there is high back-pressure? These blowers produce high airflow in limited area, and are used for cooling devices dissipating tens of thousands of Watts, such as transmitting valves (AKA "tubes", to the US).

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  • Sadly there is not enough vertical room (max 6cm) in the housing for anything except more fins – 1000Gbps Jan 13 at 21:45
  • And outside the housing? Surely a blower can be added before or after the heater. – DrMoishe Pippik Jan 13 at 21:48
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    It has a blower from hot air gun :D This is a hand made hot air station for wood burning from spare parts and the idiot created it was close to the owner. So that owner wants this abomination to work longer without shutting down and still be the same size and same level of noise. We already offered him to buy a better station but he is on the sentimental wave ... no comment :) – 1000Gbps Jan 13 at 22:06

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