Alternative to foil wrapping a P60 drop-in (thermal silicone)

I ordered a thermal pad from eBay the other day to try and wrap my p60 drop in with something other than aluminum foil or soda cans. My idea was a thermal pad, like the kind used on GPU's. I found some 1mm thermal silicone for about $5 and figured it would be fun to try it out. I have only tried it on one of my lights, an old Surefire 6P with an XM-L T6 drop in pulling around 2 amps or so. I left it on for about a minute and the light definitely got hot, and that's a good thing. I really don't have a scientific method of testing this against aluminum foil or aluminum strips from a soda can, but I would say it works just as well so far. The drop in fits really snug in the host, and when the silicone gets warm it is supposed to flow a little bit to fill in gaps.

I ordered a couple of p60 hosts with XM-L drop ins so hopefully when I get those in the mail I can try a test with all three types of heat wrapping on the drop ins and get a better idea of the performance. Pics below.

I ended up having to wrap some aluminum foil around the pill to get better electrical contact with the host (I originally wrapped the pill with the thermal pad but the light didn't work because there wasn't enough contact with the drop in and the host to complete the circuit). I pushed a little more of the thermal pad down onto the foil on the pill and it works great. I'll post some more pics later if you want em.

I think this will work better on my 502b host because I can leave the spring on the pill and that will be the negative contact for the drop in. That should allow me to wrap the pill in the thermal pad as well for better heat transfer.

Interesting, thanks for sharing.

This seems like the perfect stuff with which to heatsink high-powered drivers.

Great find. Do you have a source you can share? Thanks !

Forgot to post the eBay link! Here ya go.


Is it adhesive in any way or is it easy to remove?

DX has a few similar sheets with different thicknesses. I didn’t check but the sheets were a bit larger there.

My understanding is, the material isn't incredible heat conductive and is meant to be used a single sheet where the mere fact of it being extremely thin doesn't inhibit heat transfer. In a thicker layer as your are using here it wouldn't be terribly efficient. Aluminum is far more conductive.

Aluminum Thermal conductivity 205.0 W/m K

The thermal pad Thermal conductivity 5.0 W/m K

Nice I had the same idea 1 week ago ordering that budget thermal pad just 1$ but is only 0,3mm hope wont disintegrate with the use xD

It's not really an adhesive, it's more like a putty or clay that sticks. It can be molded into pretty much any shape. I wrapped the 1mm pieces around then kind of pressed it around to form it. 1mm was too thick for the 6P host, so I'm actually using less than what this single sheet is.

I am fully aware that aluminum has better heat conductivity, my concern was the air pockets around the aluminum foil and strips. This forms quite a seal and the drop in is difficult to pull out after it's been heated up once or twice.

It cleans up fairly well. You can pretty much peel it right off and clean off any residue with some rubbing alcohol.

I added this to one of my other P60 hosts, a WF-502b. The drop in is another XML T6, this one from DD. it pulls about 2 amps on high from a trust fire flame. This host has never gotten as hot as my Pelican M6 or Surefire 6P (all previously wrapped with aluminum foil or aluminum can strips). My unscientific tests seem to indicate no noticeable difference between all three methods. My plan now is to get an infrared thermometer and take some heat readings from the hosts over the course of about five minutes and see if tere is any difference. That's about the best way I can think of (that I can afford, no access to FLIR).

Here is a pic of the drop in I wrapped for the 502b. This one took a little more of the thermal silicone. Just a bit over 1mm, I'd guess around 1.25mm to where it's very snug in the head of the light. Again, it is difficult to remove after the light is heated up a few times. This leads me to believe the stuff is filling in all the microscopic holes and gaps in the metals.

Hmm. I might be sticking with that copper adhesive tape. Cheap, easy to use and remove. I bet it works good enough...

Copper will be far superior with a Thermal conductivity 385.0 W/m K

The adhesive may be a slight hindrance to heat movement.

I've received this thermal pad material from ebay and I'm very disappointed with it's specs/performance. I wish I would have checked the specs on it before I ordered (roughly 40 times less efficient than aluminum).

I think I'm going to give this a try...

What would be better? 1 mil or 5 mil thickness of this copper foil?

From what I read, an aluminum soda can is about .0047 (appx 5 mil)

Aluminum is less dense than Copper so the heat passes through it quicker, I would stick with Aluminum.

Hmmm, I thought the idea was to "extend" the heat sync to touch the aluminum, making copper the best choice for this.

Wouldn’t this make aluminum a better conductor than copper, which it isn’t? If what you say was true wouldn’t an aluminum slug make a better pill than a solid copper slug, which it doesn’t?

Copper is still by far the best heat sink, regardless of density. That is, unless you can afford silver.

"The heatsink material is the most important as far as the performance of cooling is concerned. In principle, the heat sink can be made of different materials. The thermal conductivity is one important issue. The following comparative table shows the thermal conductivity of different materials.

Material Thermal Conductivity
silver 422 W/mK
copper 402 W/mK
gold 298 W/mK
aluminium 226 W/mK
steel 73.3 W/mK
lead 34.8 W/mK

At first glance it is obvious that silver and copper have the best conductivity. As silver is too expensive for a massive heat sink, the manufacturers at best use copper. Using aluminum is cheaper but the conductivity is by far not as good as copper. That means silver and copper spread the heat very quickly. These two materials offer the best quality for a high cooling effect in a heat sink/fan system."

Quote is from

Check your local hardware/garden supplier.

Thin copper sheet and strip can be found in several sections, used as:

-- slug and snail barrier
-- door and window gasket

Copper scrap is easy enough to find; heat it with a propane torch to take the temper out of it (randomize the crystals that form when it's shaped or bent, which eventually make it break after it's bent often enough). Then hammer it down to whatever thickness you want, heat it again so it's malleable.

Jewelers have metal rollers that can be set to precise thickness for rolling metal out flat and thin.

I received it.. and don't recommend, low thermal proprieties and is not adhesive done with silicone and some fibers inside like nylon... give it a nice straight but as i said no good thermal proprieties

I was searching something of adherent is true copper/aluminum have great thermal proprieties but if there is also a micro air gap they low dramatically for that for example we use thermal paste between cpu and heatsinker

about the copper/aluminum tape.. the adhesive used will not low too much the performance? Considering also that u must do min 4/5 turns of tape more air gap and adhesive isolation