Thermal interfacial material / thermal grease is not easy to find, especially if you are not living in US or Europe ( or maybe if you don't live in a large city ). Even if you do manage to find it, even online, it is generally not cheap.
Anyway, I was looking for some TIM and these are the good deals I found online. Warning : I use it for computer CPUs and GPUs - I don't know if these TIMs are suitable for flashlights. The more experienced forum members could comment.
Then there’s Arctic Silver 5, the most popular and most acclaimed paste on the market. And it’s basically rubbish. In no metric is it better than MX-2, on average it’s over 2C worse than MX-2 and costs twice as much. MX-2, while it is great overall, isn’t even a great performing paste (it’s the baseline for good performance) and AS5 is far behind it. And on top of that, AS5 is capacitive, meaning it shouldn’t be used anywhere near exposed traces or SMD components (basically, should only be used on CPUs and GPUs with an IHS).
For a CPU a two degree difference can make a significant difference in how far you can overclock it. Personally I doubt that a two degree difference is likely to be of as much importance in flashlights unless you are trying to overdrive (i.e. the equivalent of overclocking) an emitter to the very extreme. Conclusion = Go with Fujik.
My general thought is that there are a dozen other things more important in getting the most out of a light than the TIM used (as long as there is some!). The difference in output using AS5 vs. MX2 vs. whatever is most likely equivalent to having an extra speck of dust on the lens or not.
If normal operation of a computer depends on a 2deg difference, better not turn the lights on/heat up/breath on it much less use it outside.
It's also probably worth noting that in the review above, there's often greater variation between mounting attempts with the same compounds than between difference ones.
When you use AS5, you should know that AS needs several days up to weeks (200 hours with hot/cold cycles) to cure and reach final effectiveness. The difference can get up to 2 to 5 °C after it's finally cured. If you take that into account you'll see the AS5 will be more or less on par with any top TIM.
Want a serious TIM test? Try here: http://benchmarkreviews.com/index.php?option=com_content&task=view&id=150&Itemid=62 it may not be up to date, but it shows how such tests should be done. Much of it is still relevant.
Grind a piece of soft annealed copper on a fine wheel until you get a heap of fine copper dust. Mix with a drop or 2 of silicone oil. Apply under CPU or Diode and press down. Also, apply copper dust mix to the part you are going to thread in, like a C8 pill.
It's kind of like with Vitamins....you can spend a fortune on pills....or you can just Eat Your F**king Vegetables.
Maybe that's OK for flashlights, but for the real use of TIMs your vegetables may have a far to big particle size. A TIM must fill gaps, nothing more. Your copper grindings aren't quite likely to be squished out of the contacting surfaces very smoothly.
I don't think I've ever heard of anyone using copper grindings for CPU heatsinking...
Get a big syringe of Ceramique 2 or something, it's worth every penny.
For CPU´s etc I would have bought some more expensive stuff. Arctic silver maybe.
With flashlights I don´t care that much. If theres something between pill and body, I´m happy. Difference is usually quite easy to notice, more likely if the threads are loosely machined...
TOOTHPASTE?! So I'm researching what grease to buy and I can use toothpaste? my flashlight will even smell nice?!
ok, so it'd dry out and make a mess if you dissassemble. Anyway, I'm going with white silicone grease, and next time I order aluminum powder (no, not for thermite for strengthening epoxy) I will mix up enough to last the rest of my life lol (for the cost of AS5)
for strengthening epoxy) I will mix up enough to last the rest of my life lol (for the cost of AS5)