Waterproof Heat Sink?

Ken_McE

Flashlight Enthusiast
Joined
Jun 16, 2003
Messages
1,687
The heatsink doesn't care if it's wet or dry. Just glue it on.
 

FredM

Enlightened
Joined
Mar 7, 2005
Messages
666
Location
Houston, TX
How much power are you running through the strip? How long is it? The Arctic Silver people - http://www.arcticsilver.com/ta.htm make thermal heat transfer glues, but usually strip lights don't run hot enough to need them.

However much it takes. I bought a few "higher power" LED strip but the voltage drop over 5m has me thinking the ~30 watt strip are better. I will probably cut the 60 watt strips in half .



Anyways, I'm running too many to use any expensive glue so was thinking Devcon or JB Weld or something. They will be going on galvanized structural beams.
 

Ken_McE

Flashlight Enthusiast
Joined
Jun 16, 2003
Messages
1,687
30+ watts is enough to benefit from heat sinking. Unfortunately I don't know if one glue is better than the others. If you can spread whatever you use thin, you will get better heat transfer to the steel. Any chance of pictures after it goes up?
 

degarb

Flashlight Enthusiast
Joined
Oct 27, 2007
Messages
2,036
Location
Akron, Ohio
Not all epoxies stand up to water. 6 minute epoxy, not so much. Arctic silver is fast, thus, I would be careful to research and test.

Yes, price is insane for arctic silver-making it only appropriate for small, single projects. So, I just add copper or aluminum powder to normal epoxy. JB weld already has steel (lower conduction than aluminum, but it is something) in it. .... The copper was costly, so only got a little. Engineering toolbox has its thermal conduction way ahead of the closest second, Aluminum. The powered aluminum I got cheap, probably was termite. So, I store it in a bag, in a tin, duct taped, and inside a larger tin, far away from fire risk ideally, labeled and in a detached shed or garage. Then again, I am just a seat belt wearing, protected cell using fellow. You may feel free to store your thermite by your bed, beside your unprotected cells.

I mistakenly bought a pound of zinc oxide, on cpf recommendation, back in 2012- have used relentlessly, yet still have 80% left, while a few builds seem to have consumed most my copper. But upon, research I do not believe an oxide of any metal conducts anywhere as well as the pure metal, much less the thermite aluminum, even less, the copper. Empirically, only crude soldering iron plus finger, heat tests across joined aluminum heat sinks. But nothing I concrete enough to draw any conclusions, about which glue, or additive, is better. A direct metal, or ultra thin epoxy (to fill micro air gap) bond, is ideal. Thermal conduction of arctic silver is horrible on their own data sheet, compared with real metal. (No luck yet soldering aluminum for me, which is my holy grail. My problem is that my builds rely on the epoxy for the form. The great plains or bob Smith 6 minute, with additive seems to last 2 years, with no water exposure. I imagine jb weld standard formula would go decades, but likely would need over night to set with additive. I was able to get great planes 6 minute to set up in 10 minutes with a heavy percent thermite two days ago. I believe I recall zinc oxide slowing down set time of bob smith epoxy a bit more, bur not too much more. Again, not tested side by side, all permutations, neither with notebook. )
 
Last edited:

FredM

Enlightened
Joined
Mar 7, 2005
Messages
666
Location
Houston, TX
Well I can tell you JB weld works incredibly. The IP67 tube strip I tested just laying on my carpet would get very HOT for the first several feet in minutes (then voltage drops and LED dim the longer the string) but I put it on the beam and it warms the beam and stays very cool even after on an hour or so.

I plan to see how it holds up for a month or so and then epoxy them all up.

I did one IP65 and one IP67.
 
Top