DIY copper mag heatsink

I wanted a cheap mag heatsink made from easily accessible parts… hence the home depot copper fittings.

1 inch copper coupler…

and a 1 inch copper end cap…

I first used a pipe cutter to cut off about 1 cm of the coupler. This way it will sit down in the mag tube completely.

Next I split the coupler down one side with a hacksaw.

I then used a C-clamp to open the coupler a little wider. The end cap then fit in snug and I soldered the two together.

Simple and effective. I’ll try to answer questions you may have

this is very simple and elegant solution. Thank you!!!


Does it fit snugly into a D mag tube?

Great idea

I’ve been mulling over how to do something like this for the past month. Nice solution! Thanks for sharing!

How flat/level is the end cap?

It probably depends on the brand of coupler & cap you find, but mine slides in easily and wont fall out if flipped upside down. It could probably be tighter, but an aluminum can strip could solve that easily.

As far as I can tell it is fairly flat. Some brands have stamped their logo on top, but this can be filed out and made flat.

My Copper Heatsinks with sandpaper become easily perfectly flat with 2~3min of sanding. Very pliable and easy to manipulate copper.


If it’s not flat enough you can always get a piece of flat glass and sandpaper and lap it as flat as a mirror

I have used copper pipe and have split it to make it fit, but using the split pipe to widen the end cap is very neat. I have a light with a hollow pill but otherwise good cooling that it might work for.

Nice and simple. Thank you!

Another person here that is running the world out of copper pipe fittings. Thanks for showing us your mod.

Hey, I represent that remark! Good mod, keep it up.

I saw similar mod over at MTBr with their Solarstorm X3 and I found this seller on eBay last time.

It might be a MISTAKE but, here, the 1.25 end caps are 53c each! No reviews.

Just checked my 2D and it’s the 1 1/4” copper pipe that fits rather than the cap.