Thermal performance between arctic alumina type adhesive and thermal adhesive stars?

turnip brain

Active Member
Theoretically I'd prefer thermal grease and screws to be able to easily remove LEDs if needed, but going with water cooling I can't drill into the heat sink tubes.

So that leaves thermal epoxy or adhesive stars. With those choices, trade off seems to be ease of application and easier removability with the thermal stars but at higher cost compared to epoxy.

What about thermal conduction between stars/tape and epoxy?

Any other methods I should consider?
 

Mechmike

Well-Known Member
The adhesive stars will work just fine but they are costly. I use this: http://www.ebay.com/itm/270717024919?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

It takes a few days to fully set but is fairly easy to remove if desired since it is silicone based. I have 402 stars on several fixtures mounted and running, some for well over a year, with no issues using this thermal adhesive. The best part is that, even though it's pricey, it's still a bargain compared to adhesive stars and much easier than epoxy mounting to modify the fixture after the fact.
 

turnip brain

Active Member
The adhesive stars will work just fine but they are costly. I use this: http://www.ebay.com/itm/270717024919?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

It takes a few days to fully set but is fairly easy to remove if desired since it is silicone based. I have 402 stars on several fixtures mounted and running, some for well over a year, with no issues using this thermal adhesive. The best part is that, even though it's pricey, it's still a bargain compared to adhesive stars and much easier than epoxy mounting to modify the fixture after the fact.
Thanks.

The "1.2W/mºC"
Leaves me notationally and algebraically confused compared to thermal impedence rating in C-in2/W notation.

 

Mechmike

Well-Known Member
I don't get the math either. I just decided to take a chance and try it some time ago because I was wanting a solution that makes future mods doable. My first try was with a small (16 stars) fixture to see if it would be suitable. That fixture is still working today as well as it did on the first day. They sell a larger tube but the small one is much easier to work with.
 

SupraSPL

Well-Known Member
I put a lot of time and money into the heatsinks but I like to be able to change the design so I don't drill mine either. I have been going through the labor intensive process of flattening and polishing the heatsink surface. Electric palm sander makes it a lot easier and faster. My solution is unsightly but works. I scrapped the Arctic Silver Ceramique and now use Prolimatech PK2 between the stars and heatsinks. The stars will stick firmly to the heatsink with ceramique or prolimatech but since it is not an adhesive I use kapton tape to strap the stars down and assure they cannot move. That is the unsightly part but kapton protects the exposed electrical points, the adhesive holds very tight and does not leave a residue.

Is all that really much better than using a thermal adhesive? Probably not since I am running at 700mA but I will take any increase in efficiency I can get.
 

pepperdust

Well-Known Member
I had an idea with water cooling..

I was going to use copper plates, so I could just switch out when I wanted, keeping the surface fine.

screws for the ends of the copper plate, and find hardware, that seals the hole? ( can you do silicone for like fish tanks when you look through the bar, to waterproof the holes/bolts coming into the tube??? )

also you could do some makeshift 'clamp" at the ends to hold the plate on... even something like the idea of zip ties... I don't know



my thoughts on that
 

SnotBoogie

Well-Known Member
Personally i use arctic silver 2-part epoxy for the MCPCB/heatsink join.

Im pretty sure theres been a thread recently about this, let me wander off and find it!
 
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