Home made heatsink epoxy- Mtbr.com
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  1. #1
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    Home made heatsink epoxy

    Now I wish it was my idea but no .

    just browsing over at CPF and saw this

    qwertyydude
    Flashaholic Join Date: Aug 2008
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    Homemade heatsink epoxy

    --------------------------------------------------------------------------------

    I didn't know where to post this but if you ever need to make heat sink epoxy, which I needed for some projects of mine, a good way is to use a sanding drum and sand a block of copper. I used a fine 320 grit drum on my dremel. And using light pressure I sanded a small block into a pile of dust. To make the regular 5 minute epoxy as heat conductive as possible I mixed as much copper dust as possible into 5 minute epoxy as to saturate it into a thick almost non adhesive paste. Applying this as thinly as possible and wringing the two objects to squeeze out air and excess epoxy and applying pressure until dry resulted in the led star making incredible thermal contact with the heat sink plate.

    For comparison I used a regulated, overdriven 1.4 amp R2 led on a star. This is attached to a black anodized heatsink with the anodizing sanded off the base where it makes contact. I maxed out the test at 130 degrees. The artic silver epoxy reaches 130 degrees in about 3:30 minutes, my custom mix reached it in about 3:10 minutes. I'd say a significant improvement.

    Now this is only good for non electronic uses because this stuff is actually conductive, I measured a direct ground from the star to the heatsink base. But since it is electrically conductive you know it has to be a nearly ideal heat conductor since it is made of copper. It's got to be at least as effective as soldering for heat conduction. Plus it is really really cheap to make. So if anyone is interested here's a cheap way to heatsink stuff.



    This seems a good idea for when you want a large ammount for say fixing heatsinks into tubes or torch bodies when arctic alumina is very expensive to use .

    Here is the thread
    http://www.candlepowerforums.com/vb/...34#post2706834

  2. #2
    www.hahntronix.com
    Reputation: mhahn@hvc.rr.com's Avatar
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    Be careful when sanding copper, it is a lung irritant and also toxic.

    I ground down less than 1/4 of a gram of brass (has copper in it) in my garage last winter and was wheezing for days afterwards. I had the doors and windows open figuring that would be enough ventilation. It wasn't.

    You should be careful sanding any metal, they can all cause lung problems. If I sand metal, I do it out on my driveway, with a strong fan blowing behind me, and I wear a respirator.

    If you want some powdered metal, it's usually simpler and safer to just buy it.

    Mark

  3. #3
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    5 min epoxy holding up to the heat?

    Great idea but does the epoxy component actually hold up to the heat? Regular 5 min epoxy disintegrates at very low temperatures. I use to remove my epoxied ski pole tips by dipping them in hot water. It almost turns to powder. How about using the "epoxy" used for engine blocks as a base? You would not want the epoxy turn to mush and the LED loosing the connection to the heat sink after your second day of riding.

  4. #4
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    Quote Originally Posted by [email protected]
    Be careful when sanding copper, it is a lung irritant and also toxic.

    I ground down less than 1/4 of a gram of brass (has copper in it) in my garage last winter and was wheezing for days afterwards. I had the doors and windows open figuring that would be enough ventilation. It wasn't.

    You should be careful sanding any metal, they can all cause lung problems. If I sand metal, I do it out on my driveway, with a strong fan blowing behind me, and I wear a respirator.

    If you want some powdered metal, it's usually simpler and safer to just buy it.

    Mark
    Brass also has lead in it- which is definitely something that you don't want to breath...... I highly recommend reading MSDSs for anything you work with

  5. #5
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    I did a bit of googling and cure time does not seem to be directly related to working temperature range for epoxy resins. Just check the instructions, most will say it maintains high strength up to 70C or so, which is probably fine. Potting resin is rated for higher temperatures and is probably ideal for this application. I've used Araldite glue with aluminium powder myself, done mucho testing and it works fine.

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