Would you guys please recommend a thermal glue or epoxy that I can stabilize a star onto a flat aluminum piece without screws or a reflector sitting on it? I once used a thermal plaster I got from DX, sold in tiny tubes and it seemed to work but anything better is much better :)
BTW, I have some two component epoxy resin glues at home that I use to fix things and they seem to dry hard like plastic. Do these epoxy resin glues conduct heat or isolate surfaces? They are rated up to 120 degrees Celcius.
I've ordered some of DXs fujik glue (says grease in description but reviews say glue).
I've used arctic silver grease under a star and then dripped jb weld onto a few of the star points before. Works ok but takes a very long time to cure.
I also have the Fujik stuff. The one sold in the barrel is thinner and grease like. The one on the big tube is thicker. I couldn’t see much adhesive properties of either but maybe I should have waited longer for it to cure properly. The tiny yellow tube of thermal plaster sold on DX, on the other hand, was more like a glue.
Arctic Silver & Alumina can conduct electricity. Since they have metal in them. I use Arctic Ceramique (thermal grease) if I have to worry about conducting electricity, then Alumina or Silver around the outer edge. (Only applies to some emitters).
I use Fujik from DX it works great for sticking stars on. I also use it for potting pills. The tube is a little messy, but otherwise it's a great product.
Ok. Tried the Fujik adhesive given in the links earlier today and cured it for longer this time. Now it seems to hold on better than before. Maybe my cleaning with isopropyl alcohol helped it.
The one in the small bottle doesn’t harden like this. It is softer and looks oilier. It is a good transfer material though. I used it for several times where reflector pressed on the star and no adhesion were needed. The body heats fast by the help of this compound.
The common epoxy plus materials sounds interesting. I still would like to stick the star with Fujik and coat them with epoxy to fix further.
I have used the copper grindings to thermally 'pot' holes in budget pills, before acquiring a lathe.
One can mask off one end of the pill with silicone-infused parchment paper (found in baking aisle) then fill the hole with a 50/50 mix of epoxy/copper to the level required.
Be conservative in filling, as it's easy to add more, but difficult to remove material after curing.
I would avoid any metal-based epoxy, be it homemade or store-bought, where electrical conductance is a concern. As Old-Lumens mentioned, the "ceramique" is a good choice in these situations.
The fujik is a mess. I used it a few times than i had troubles getting it out. Should i try with a syringe trick when buying a new one? Anyone did that with good results?
I've never tired Fujik. Maybe I should, to see how it does. The other reason I like the Arctic stuff is it seems to hold up well under constant heating/cooling cycles, seen in a flashlight.
Fujik works nicely if you put it in a syringe with a cap. But heat conductive proterties are 8x worse than arctic alumina epoxy 2 component glue.
This makes me wonder if the fujik stuff is just a plain silicone mixed with generic thermal goop, which probably is (and we can make a better one at home probably). Heat transfer is in my opinion heavily impaired with fujik vs good thermal glue or plain thermal compund and screwed down tightly emitter (like cpu/heatsink bonding). I'm quite sure tha majority of the fujik applications around are way too thick. I use like 1/3 of a grain of rice and press it like there is no tomorrow hoping to jsut fill the gaps and the bond lasts.
If anybody has doubts, just look at the graph. The led was attached with fujik, and you see how performs at 3A compared to BC40. Ignore the 4A curve, you know why.
After 7 mins the difference was less than 20 lumen, that's good I think.
keep in mind that the brightness values are relative, the multiplier factor is 0.8-0.85 if you want to get real lumens
What is BC40 anyway? I would really like to see it compared to premium stuff. Also, how it was done also take a tax on the result not just the goop used. I suspect fujik is relatively a poor choice but it surely beats generic cpu thermalpaste mixed wuth some glue.
Anone doing it with arctic alimina epoxy? Hows the smell?
