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Delete if repeat of What dielectric liquids can be used as coolants?. I got a cheapo 42v PSU to charge my skateboard. It gets quite hot, and I was thinking of injecting some Vasaline in there. Is this a bad idea? Is there anything else I could use? I'm more interested in static jellys since they won't flow out the cracks.

Emmanuel Lopez
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    Coolants work by boiling or flowing away, which carries heat with them. If you goal is to use a material that won't flow, how is that going to help with cooling? – user1850479 Aug 05 '22 at 00:58
  • Adding can and heatsink may help. – user263983 Aug 05 '22 at 02:47
  • Vaseline produces flammable gases when heated enough. Do you really want that? – Andy aka Aug 05 '22 at 08:19
  • Sounds like a bad idea in terms of safety. You could try adding a heatsink and new thermal compund, but personally I don't like the idea of messing with the internals on high voltage equipment. Futhermore vaseline is flammablae, so putting it next to something that heats up is a bad idea – F.Ahmed Aug 05 '22 at 11:26
  • I ended up getting my hands on some silicone axle grease. – Emmanuel Lopez Aug 16 '22 at 01:49

1 Answers1

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Heat transfers by 3 methods:

  1. Conduction. Heat flows through materials. If flows well through metals and a few other materials. Still air is a very poor conductor. Vasaline is better than air, but not a great conductor.

  2. Convection. Moving gas or liquid can carry heat away. Hot air rises, so convection currents will be naturally created. Forced air flow via fans can be very effective.

  3. Radiation. An extreme example is an incandescent filament that radiates heat through the vacuum of the bulb. Some radiation will occur at lower temperatures, but it is probably negligible in your situation.

So, basically, you are hoping that the vasaline conduction is better than the natural convection of the air. If your electronics is in an enclosed box, you may have minimal convection and the vasaline may be better. The calculation is complicated, running tests is probably easier.

But a better solution is usually to create forced air convection via a fan. Fans work wonders. There are a few downsides: 1) they have a shorter lifespan than most electronics. 2) when they fail, your electronics may overheat and be permanently damaged. So, if your device depends on the fan, you usually want some type of automatic overtemperature shutdown. A bi-metalic thermostatic is one way to do this.

Mattman944
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