Was doing a search on heat sink thermal compound because I need to buy some more and started wondering if i could use the acne cream,desitin ointment(for diaper rash) or sunscreen lotion ? Zinc oxide sounded awfully familiar from the countless hours of reading the backs of bathroom toiletries over the span of ones lifetime .
"20 percent zinc oxide is optimum. She recommends sunscreen, SPF 30, with 18.75 percent zinc oxide."
I need to find a light I really don't like very much and test this .
Lol vegemite and toothpaste works better than some thermal compounds. I thought the silver in thermal compounds would improve thermal transfer, since it would mimic metal-metal contact, but I guess it is negligible. Alright, Fujik it is then.
The main ingredient in heat sink compound I believe would be berilium ceramic along with other metallic oxides suspended in silicone. The problem with using something else such as sun screen or the like would be the fact the carrier of the metal oxides would dry out or evaporate and all that would be left would be sand like particles which would decrease the contact area of the LED to the pill. The silicone carrier in heatsink compound doesn't dry out which is why it remains effective over time.
LOL vegemite… I bet with heat that would smell funny. I usually just use arctic silver or what I call plain old white monkey snot on less demanding jobs.
Since heat sinking is related to computers and other electronics it seems the thought wasn't original ...makes you wonder what's really in the goop you're putting under your emitter or cpu ...
one things for sure....my flashlight won't have athletes foot.
My personal experiences between the following do give some rough relative differences in the compounds, based on physical handling properties, confirmed by the posters analysis.
White ceramic type
Cheap silver stuff and,
AS5
1) the white ceramic dries out within months->years, wipes clean.
2) Silver stuff doesnt wipe as clean, but can be pretty clean after some good wiping (decently smaller particles)
3) the AS5 will not wipe clean. therefore much smaller particles that will fill cracks better. (Much better in un-lapped heatsink interfaces, which is commonly encountered in torches)
With the conclusion from the other forum saying that for un-lapped surfaces, AS5 is still more ideal. Realistically, who laps their emitters to their torch? I try to, but I never go as far as to get a mirror finish. It is however a more expensive material, with my big 12g tube costing me $19 AUD, but in applications like my triple XP-G pocket torch, its nice to know I can add a couple more seconds to my 60 second max run time on max.. haha
The thing about using heat sink compound is that it is only pretty effective when there is enough pressure in the first place and the gap is small, so it fills up. If its a typical P60 host + drop in, it does literally nothing at all, seriously really nothing. If you add aluminum foil its just decent but still nothing great. Copper may improve a bit. I think it is only when you extremely carefully wrap it up nicely in a repetitive pattern, hence no gaps between the foils, does the foil method + heatsink compound work beautifully. ie you need to get as close as possible to providing a solid/unbroken thermal path. Alu foil is mealable, so it really needs to be very tight. Just spending 1 minute causually wrapping foil over it does not do much.
I tried alu foil and HS compound, wrapping is just how you'd casually fold the foil up and then wrap a little over too much and screw the P60 into it giving you tight enough pressure that the drop-in is stuck inside and does not pop up....... with a L2T and the fav/ubiquitous XM-L drop-in, that combo takes in more current but still loses pathetically to a Yezl M7X which is very similar to a P60 size format. (the Yezl gave me nearly twice as much lux from a ceiling bounce while taking in some 0.3A less, there is absolutely no mistake it is brighter).
I'll give it one more try and get whatever Fujik stuff. My computer artic silver or whatever Noctua (the HSF combo costed me nearly 100 bucks) ran out!
Then comes the next question. If you take so much effort to do it up, you probably wouldn't wanna mess it up and change the drop-in.
And finally the last question, if this is the case, why are people spending so much on Surefire hosts and 5.6A quad XP-G drop ins, yeah I know its potted well?
PS. I understand now, even this careful wrapping of alu/copper foil, carefully coating a very very thin layer of thermal compound for every fold, and fitting it into the host perfectly, with whole process taking 20 mins or so.....is an enjoyment of the hobby by itself!
Thermal Transfer Compound Comparison |
| from the one-person’s-perspective dept. |
| posted by Fnord666 on Thursday September 10, @08:18 (Hardware) |
| Thermal Transfer Compound Comparison - SoylentNews |
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Most CPUs don’t produce enough heat that the stuff you put between the chip package and the heat sink matters very much, as long as the computer case has decent ventilation and the ambient temperature isn’t sauna-like. There just has to be something between CPU and heat sink.
The reason why there has to be something there is that the two mating surfaces of processor and sink aren’t flat. They may look flat. They may have a mirror polish. But, on the microscopic scale, they look like a scale model of the Andes. And the mountains on one item do not match the valleys on the other.
Without thermal transfer compound, everywhere heat sink metal doesn’t mate with CPU package material is a teeny-tiny air gap. Air is a good thermal insulator. As long as your heat sink looks flat when you lay a ruler on it then there’ll be a decent amount of actual contact, of course, but the amount of heat that’ll actually make it around the air gaps may be surprisingly small.
Hence, thermal compound. It’s grease with lots of minuscule thermally conductive particles mixed into it, basically. It doesn’t conduct heat as well as direct contact, but it’s a heck of a lot better than air gaps.
I don’t think it could be based on berylium due to its toxicity. Most of the pastes I encountered are usually based on Zinc Oxide or Aluminium Oxide. Some of the more exotic ones are based on carbon nanotubes.
.. gotta love a product called baby butter
