Hi all,
I have a few extra batches of the 2 part epoxy here. All of them that I have used so far are very fresh. No yellowing, hardening etc inside the tubes.
https://asflashlights.com/more-/122-arctic-alumina-2-part-epoxy.html
I just spend last tube of Artic Alumina :person_facepalming:
Artic Alumina was top non conductive, ceramic thermal glue! And they discontinued production?
Arctic Alumina Adhesive is a pure electrical insulator, 0% of electrical conductivity!
This is serious and the best stuff for certain type of LED emitters. In the beginning Vinhnguyen from CPF and plenty other guys used this stuff for mounting MCPCB…
Do we have alternative for Artic Alumina :question:
AS5 has been inferior to other products for at least a decade. Capacitive + curing…
Diamond paste is almost universally better, there’s other pastes similar/equal to AS5 without curing time.
You’re mixing things up. This thread is about Arctic Alumina thermal adhesive NOT Arctic Silver 5 thermal compound.
Arctic Alumina adhesive is a fast curing non-conductive thermal epoxy. It’s great when you want a permanent bond. I use it in flashlight mods to glue switches in place, among other things. As an epoxy it comes in 2 tubes. You have to squirt out an equal amount from each tube and mix them together before applying.
AS5 is a thermal compound. It’s meant to provide heat transfer but is not an adhesive. It’s still around and is fine for putting between stars and shelves. Diamond Paste sounds like another thermal compound. A better replacement for AS5 perhaps, but it’s not an epoxy so can’t do the same things Arctic Alumina can.
I recently went looking for an Arctic Alumina adhesive replacement. I purchased some MG Chemicals 8329. Specs look good and you can get it with various working times.
I have also used MG Chemicals 8329. It is good, but I still prefer Arctic Alumina adhesive. They are not the same.
The search for the alternative continues.
The Alumina was probably discontinued because it hardened by itself even before mixing.
Currently there is nothing that has similar performance, all other thermal epoxies are about 1W/mK.
If you really need higher performance you should be using thermal paste, then securing the part using screws/retaining rings or even gluing it with some JBweld.
For gluing on switches and things I don’t really care about thermal performance of the glue. I want something that cures quickly, is not electrically conductive, and will hold its strength even under high heat.
JBweld has a wide selection of fast curing high heat epoxies 
“The Alumina was probably discontinued because it hardened by itself even before mixing.”
I will confirm that tubes i used lets say twice and forgot for them lets say couple of months have hardened… But not both… Only 1 of them hardened…
Enderman,
This is very good thermal performance stuff, pure electrically insulator, permanent 5 minute stuff… Especially for certain Osram IR LED emitters… But not only them… This is serious stuff when you don’t have MCPCB retaining ring, screws etc…
There is no replacement for this stuff I’am afraid 
Enderman could you tell which JB weld could be good alternative? I have JB weld (red/black 2 component epoxy) and I know it is non conductive but this is “cold weld” 24 hours epoxy stuff… Maybe it has some thermal conductive properties but I guess they are not even 10% of Artic Alumina performance…
Maybe we have cheap China Aliexpress alternative?
this stuff should actually be better heat transfer but the price and setting method lol Ceramabond™ 865 Aluminum Nitride Adhesive
quick google shows no other aluminum oxide adhesives, which is weird. capitalism die out all of a sudden?
Artic Alumina…
Why they call that “Alumina”? This is freaking white ceramic thermal compound(or better say 5 minutes epoxy).
But it is the best quick epoxy stuff, and most important it is electricity insulator with very good thermal properties(if you can’t make 2 perfectly lapped surfaces than I claim with my experience this will be better than any thermal silver/diamond/liquid paste).
What about the half’n’half trick? Ie, half AS5 or similar, and half 2-part epoxy.
That was the “trick” if you wanted an adhesive you wouldn’t have to chisel off later or just grind down the star to the bare shelf. Not as permanent as pure adhesive (AA), but also decent properties.
Never did it myself, but there were plenty of posts here about doing that.
Or just get some Fujik.
Fujik sucks and AS5 with 2 part epoxy sucks when you need to fit LED emitter which has thermal pad that is not electrically neutral…
So either isolated MCPCB must be used or even better mentioned Artic Alumina above.
I personally use the regular stuff, it takes long to set but it has the highest strength of any epoxy.
You don’t need high temp stuff, LEDs don’t get hot enough to require that.
They have quicker setting epoxies too if you want, with slightly less strength than the classic.
Alumina is a type of material that is thermally conductive and not electrically conductive.
Also it is not better than liquid thermal pastes, it is only 4W/mK, most thermal pastes are double that.
Thanks,
I have original JB weld like in your link… I don’t know… Maybe I’ll test it.
For other reply it is better in a case where you have 2 uneven, unprepared rough surfaces, and in a case where you don’t have MCPCB retaining ring screws etc…, also for fitting of certain heatsinks and LED emitters which can not be fitted with thermal pastes…
The thermal conductivity of something like Kryonaut or MX-4 is better significantly.
You just need to find a way to secure the thing down since it is not glue.
That’s what thermal pastes are specifically for, two uneven surfaces that need to transfer heat.
I think it’s non-insulating but claimed to have good W/mK
It’s not great.
