Regular epoxy to glue Luxeon to heat sink?

[BatteryCharger]

I know most people here use something like Arctic alumina epoxy to glue their Luxeons to their heat sinks. What about regular epoxy like you find at hardware stores? Will that work for a 3 watt run at about 1-1.2 amps on an O-sink?

 

[greenLED]

The artic alumina epoxy is used to ensure proper heat conduction into the heatsink. I don't think regular epoxy works as well to conduct heat away from the Lux and onto the heatsink/body.

 

[BatteryCharger]

I know it's used to conduct heat, but considering I'm hardly overdriving and will only be using a *TINY* amount of epoxy I wouldn't think it would be much of a problem, but then again I've never tried it. /ubbthreads/images/graemlins/smile.gif

Since I only need a drop of epoxy I don't really want to spend $7 on a whole tube of Arctic alumina when I've already got a tube of regular epoxy...

(If anybody has a mostly used tube of Arctic alumina they'd sell for a dollar or two I would be very happy /ubbthreads/images/graemlins/grin.gif )

 

[WildRice]

I have been using 5 minute 2 part epoxy mixed with a bit of thermal paste (rat shack) on all my mods. I have not had any problems. On my 3D m@g with a hotlips and a LUX III, I used a smudge on thermal paste under the emitter, snugged it down good, then epoxied around the outside. I put a little pressure on the emotter from minute 4 to about minute 6 to ensure it was dawn as far as possible. Its has been working great.
Jeff

 

[ZuluWhiskeyFox]

One thing to keep in mind when choosing your epoxy is what temp is it rated for. Not all epoxies are created equal. Most will begin to break down at a surprisingly low temp. The one that I found to work well and has a relatively high temp rating is JB Weld. And a lower temp rating but still adequate is JB KWIK. Some time ago maybe close to a year ago I started a discussion on this very topic in the Sandwich Shoppe forum. I was wondering what type to use. The discussion mostly revolved around potting. However since I have used mostly JB KWIK. Have had no problems.

 

[Krit]

I use steel epoxy 5 minuites setting time. All 1-3-5 watt luxeon work fine and very well heat transfer. Also AA I used with the same result of heat transfer.

 

[HarryN]

I was doing some bench testing and was in a hurry one eve - so I tried super glue to bond a Lux III to a fairly large Al plate. Very thin layer, dries quick, etc.

It works ok, but I did a quick test using gadget lovers Lumen box and above 350ma, the output fell substantially off of the current vs output curve. I assume the issue is heat transfer.

My personal favorite so far is silver filled epoxy bonding to an anodized Al surface, but I have not done a thorough engineering test.

 

[3rd_shift]

I tried regular epoxy once.
It was almost as good as Arctic alumina.
But not quite as good.
I still go with Arctic alumina, or more often than not,
Arctic Silver for all my mods.
With 1 watt emitters though, regular epoxy with the emitter(s) clamped down ought to do the trick.

 

[Chop]

I don't know. After all of the money that you spend on the parts to build or modify a light, why would you cut corners on something as inexpensive as thermal epoxy?

I can see potting a converter in two ton epoxy (even better with aluminum oxide powder mixed in), but the emitter needs to get the heat away from it as quickly as possible.

 

[WildRice]

The main reason I have stayed away from Artic Silver is that I have 3 boys that like to get into everything. including my electronics. Silver paste is just one more toxic thing that they could get into. LIS (like I said) I have had good luck with old school thermal paste.
Jeff

 

[evan9162]

check to make sure the epoxy you want to use won't soften up and lose holing power as it gets hot. Lots of generic epoxies do this.

 

[andrewwynn]

when doing a 'quick n dirty' attachment (for prototyping).. i just used a tiny dab of superglue with a donut of RS thermal paste around it.. i've run those emitters over 1.2A before (which is extreme over drive on a lux 3 btw).. I would definitely use good heatsinking on anything over 700mA.. i even use arctic alumina on the nano mods which only run at 440mA.

 

[twentysixtwo]

There was another thread recently about using crazy glue (CA) to attach Luxeons. Summary: Contact between the Luxeon and the heat sink is more important than the thermal conductivity of the adhesive since the Thermal Conductivity of the best thermal adhesives pales in comparison to that of most heat sink materials.

In theory, if both were perfectly smooth and flat, using water, CA, AA, or nothing at all would be identical since the layer between the Luxeon and the sink would be zero.


I would rather have a ultra thin layer of CA than a ~0.5 mm thick layer of AA. Of course, if for some perverse reason you must have a ~1 mm thick layer of goo, AA is about as good as you can get.

What does this mean? Make sure your surfaces are flat and smooth, and if you do use a thermal adhesive, make sure you squeeze out as much of it as possible.

 

[TSellers]

8 years later and this is still a very relevant topic. So relevant it's probably worth revisiting just to address the question, have there been any recent developments in thermal adhesives since 2005 that are worth consideration, or is this info just as Germain today as it was then?

 

[Rod911]

8 years later and this is still a very relevant topic. So relevant it's probably worth revisiting just to address the question, have there been any recent developments in thermal adhesives since 2005 that are worth consideration, or is this info just as Germain today as it was then?

To this day, I still use this technique with no issues. The key is to use the smallest amount of epoxy/glue along with thermal paste of your choice. Afterwards, apply as much pressure as you can. The recent mods I did, I stuck a couple of heatsinks together this way and stuck said heatsink onto the underside of the LED shelf and that setup seems to be working.