Thermal paste

SRA soldering products has this Al26-181-75 aluminum to aluminum, aluminum-copper soldering paste. Melts at 217C(423F)

The best thermal paste at the moment is “thermal grizzly” and not Arctic Silver 5! :person_facepalming:

Kinda spendy, though, for marginal benefit (a couple of °C).

If you need the absolute best, by all means. But wow, I got sticker-shock the first time I priced TG.

I’ve had good results myself using Arctic Silver Ceramique 2.

Normally I use MX-4 unless I need something for a super special applications, MX-4 has a great balance of performance and price. Also use a gallium alloy TIM when I can. If I recall pastes normally work better than epoxies given a good level of pressure. Pressure is often just as important as the TIM you use.

Yup, I would highly recommend using a thermal paste + screws rather than a thermal epoxy.
Better performance, easier to swap out LEDs, and less damage.

I will get tomorrow most likely my aluminum solder stuff
If it works like this I will solder stars to aluminum head

The flux residue has to be removed with water as it is corrosive

Well, when trying to solder it to something that is intended to be a heatsink it will be really hard to get it to melt…
Make sure you have a 60W or more soldering iron and remove all drivers/o-rings/plastic from the light before you heat it up to 200C+
Since a flashlight is built like a heatsink, getting the head to 200C will probably make the rest of the body sit at over 100C.

Long ago I tweaked my PCs
Water cooling and high end stuff
Arctic silver was the way to go
Then a completely overclocked PC with several water cooling loops and a real expensive video card was my pride and joy
It scored really high on several tests but alas it sprung a leak after half a year of operation.
While looking for what to build next I ordered a basic really cheap motherboard with onboard graphics that accepted my CPU.

It wasn’t long till I realised that despite much lower benchmark scores this setup did what I wanted and not feel slow.
So I waited a bit with ordering a new setup. I looked through my parts bin, and measured all components temps, stuck heatsinks on all that became hot.
Lol I had so much heatsinks just the silent fan of the power unit gave enough airflow to keep all cool.
Holy dang, this PC was silent and fast enough.
On top of that after half a year I received a letter from the energy company and got a refund twice asbhigh as the parts that I bought to get it going had cost me.

One of the things I bought with my order was a big syringe with cheap thermal paste
I did test it and compared to the Arctic silver it had my CPU 2°C higher at burnin tests.
But the stuff cost me FL2 (like €0,80 $1,10 ) for a huge amount where the Arctic stuff was$6,50 for a tiny amount.

I used it but it got lost during the move here, I ordered something similar for I think $1 or $2 on AliExpress and it works nice.

Just fyi, heat is measured in watts not degrees, so 2C doesn’t really say how big the difference is.
2C drop on a 150W CPU is far more significant than 2C on a 50W CPU.
Also a big reason why you pay more for high quality thermal compound is so that it can last many years without drying, because when it dries then the performance drops.

HY710 20g Silver Thermal Compound Paste Fett Silikon für PC CPU Kühler Sale - Banggood Deutschland sold out-arrival notice-arrival notice

The thermal conductivity of that stuff is absolute crap.

Buying good quality thermal compound like MX-4, NT-H1, IC-D will make a huge difference.

That's true. In this price range the only useable paste is GD900. This stuff is almost as good as AC mx2- mx4.

How do thermal pads rate as a comparison? We use them for led modules/cob with an output up to 4000Lm.
We also use what looks to be a metallic type thermal pad which is extremely delicate and tears easily.

Much worse.
Never use thermal pads if you can avoid it.

direct soldering > liquid metal > thermal paste > thermal epoxy > thermal pads > nothing(air) > insulator

30g GD900 for $3.37 it is definitely a fake :slight_smile:
It is better to take in a blister from GD Official Store

Just to note, these thermal pads are used on lighting for shopping centres and are on constantly. 5 year warranty. Never had one fail yet.
May be worth a test and see how they do in a torch

Arctic silver 5 is 8.9 w/mk, the above is up to 50 w/mk or am I reading that wrong? Option to request a sample on the site. May be worth sending a sample to djozz

Often in manufacturing it is simpler and cheaper to use thermal pads.
They do work, and usually it is fine because the cooling solution is more than what is necessary.
As long as the temps are within the rated operating range there is no reason to spend more money on higher thermal transfer.
In commercial applications you only spend what you need, the rest is profit.

For people who want the best cooling possible for their flashlight, then thermal paste is better :slight_smile:

I have this paste from two different seller, one from official gd seller, and the other from this seller. Absolutely the same paste. Same good paste.