Well you are wrong. Again, I’m not trolling. I kinda suggest you quit going there with that deal. It’s better that you understand you gain nothing by name calling or trying to paint someone negatively so that you try to look superior to others.

Now reread edited post #124 to better understand where I’m coming from.

Performance discussions about leds used in flashlights, however heated, however annoying, however one seems to not understand the other, are not trolling.

A troll has no opinion, has no conviction, does want to convince someone else, he just wants to mess up. This not going on here.

Well, at any rate, the BLF Rules prohibit fighting, and regardless of a user’s opinion or motives, this is always the best course of action:

I’ll lock this thread for now. If there’s something else to add the technical discussion please PM me and I can re-open it after tempers calm down.

Thread re-opened. To those who participated in the argument that broke out, please go back and delete those posts. Thanks.

I read the Texas Ace test that showed that a cheap thermal paste is just as good as a top one for flashlight use.
But Osram LEDs are quite vulnerable to bad thermal transfer. I have GD900 and I wonder if it’s worthwhile to invest in something better?

Arctic MX-4 won’t let you down.

Cheap thermal compounds tends to dry very fast.

Very worthwhile to invest cause you don’t want weak link in your modd or build.

If you have two copper surfaces, liquid thermal paste is the best way to go (it’s much, much better than any standard paste). Otherwise something like Arctic Silver 5.

The flatness of the surfaces will make the biggest difference though.

In my experience GD900 works rather well and is quite sticky.

Besides GD900 and way price-ier there's GD900-1 and then GD007


If you want to use liquid metal, conductonaut is the best option.

If you want regular thermal paste, I use MX-4 because it’s one of the best but also has other advantages like being cheap for a large tube, being easy to clean off, having low viscosity, etc.
Other thermal pastes that are good include NT-H1, kryonaut, IC diamond.

Thanks for the answers. I may try better GD pastes one day.

Frankly, I forgot that the first light I’m going to try has a brass pill. So I think liquid metal is an option?
Though if I go this way, my pick will be galinstan as it’s way cheaper than the other options.

But for alu this doesn’t work.

GD-900 that I have is only marginally worse than MX-4. Definitely the difference is not worth the investment.

If I were to switch, I would probably go with Gelid GC-Extreme because it:

  • is nearly the top performer
    • which maximizes the improvement over GD900
  • doesn’t have problem with drying
  • is not very thick
  • is alu-safe

It is expensive though.

All non-liquid-metal thermal pastes are fine on aluminum, never had problems with MX-4 drying out, it’s been in my PC for like 5 years now and temps are the same.

On he other side, I had/have problems with MX-2, after few months it's completely dry? AS-5 was similar, dry after few months.

Why do you need such thermal pastes and extremes? This led gets the maximum output at low currents around 4.5A

I can’t wait to get mine!

Kryonaut is also known for drying up.

That’s exactly my question. :slight_smile:
We can discuss what is better and what is worse. But is the difference going to be 0.1, 1 or 10% with this LED? Anybody bold enough to make a guess or curious enough to try?

Meh, looking at the surface areas of LED board and shelf, this is like 100 times larger than the thermal slug of the LED.
And as long as there’s just a thin layer in between, so preferably with screws or other wise pressed down firmly, it will be fine.
Many tests have shown this.

The drying up seems like the biggest problem though.
Once the grease is dry, it will do a poor job.
So frankly, i think you could maybe better use silicone grease than thermal gunk that will dry up.

When you cool an LED more it gets its maximum output at higher currents and also outputs more lumens/lux.

Some quick calcs.
If the 980 lumens peak from Led4Power’s test is accurate we can expect almost 300cd/mm^2 out of this emitter.

I read that conductonaut affects bare aluminum not sure if this would be the best option for an aluminum flashlight.

Look here:

Yes I know it can’t be used on aluminum.