Lately I have gotten back into flashlights a little. Not only did I get a really interesting light designed by flashlight connoisseurs that I wrote about recently, but I also received a P60 drop-in that I can put in any one of a bunch of different P60 hosts that I have. The drop-in uses a recently introduced Cree XP-L “High Intensity” LED, which instead of having a round dome of clear plastic over the light emitting die, has a clear flat surface. The dome works well in gathering light and shooting it out generally in one direction, but if you’re going to use a reflector anyway, the dome acts like a magnifying lens, making the die appear bigger to the reflector and therefore harder to focus. The flat window results in a smaller appearing die that the reflector can focus better, resulting in more throw. The light I got recently has the domed XP-L “High Density” LED while the drop-in has the tighter focusing XP-L “High Intensity” LED, and in a somewhat larger reflector that is used in P60 drop-ins. It has less light output overall and isn’t drawing as much current as in the smaller high performance light, but still shines more light on distant objects.
The new drop-in got me playing around with some of the different P60 hosts I have to find a good home for it. Some of the hosts really aren’t that great and I had fun a few years ago baking a couple of them in the oven to turn them from black to a copper color. I found one light that was kind of a failed purchase for me. I ordered the host and drop-in together when it was advertised having a super duper LED (for the time) SST-50 LED, but when it arrived, it had kind of a run of the mill XM-L LED instead. The seller gave me a partial refund eventually, but the XM-L drop-in wasn’t something I would want. It had a cool white tint and the modes were High, Medium, and Strobe. I really don’t like cool tints and like strobes even less. But the host seemed decent: a clone of a nicer Solarforce L2, which itself is a clone of a pricey American light, the Surefire 6P, used by a lot of police officers. It came in boring black like another nearly identical clone I already had. So I thought I might try baking it today and seeing how it would turn out. At first it didn’t look like it would change colors, but after 20 minutes or so on broil it finally changed to copper. The body tube looks like the color of new copper pipe, but the head and tail came out more of a brown. I still think it’s an improvement.
As I was rummaging through my old drop-ins I found one I had bought a while back with a Cree XT-E LED. The XT-E came out in 2012 with a flurry of other LED’s I wrote about, but was never adopted in flashlights due to a distinct yellow spot in the beam. So I never had much use for the otherwise cool white XT-E drop-in, though I liked that it had 3 non-blinking modes. I also found a Nichia 219B LED mounted to a copper circuit board that I had ordered a couple of years ago. I like buying new LED’s so I can add their pictures to the Flashlight Wiki, but the Nichia LED has a great tint and high color rendering so I was hoping to use it in a flashlight one day. It occurred to me that it might not be that hard to remove the XT-E with the ugly yellow spot in the beam and swap in the Nichia LED. My soldering equipment is really awful because I never have spent the money to get a good setup. Still, I got out my crappy soldering equipment and after being frustrated with one soldering iron, found another that worked okay and let me remove the XT-E and install the Nichia 219B. And it worked! So that was pretty nice. Now I had a new-looking 2-tone copper colored host and a 3-mode drop-in with one of my favorite LED’s and no strobe!
I did some more tinkering lately. I ordered an AA size light, the ThorFire TG06, which some people at BLF liked because it was easy to modify. It comes with a cool white Cree XP-G2 LED, so I ordered another Nichia LED for it. This light is kind of odd because when you turn it on, it is on High, then a half press gets you to Low, and then Medium. It comes with a forward clicky (also pretty unique) and includes different color rubber switch covers for the tail (comes in black, but I switched to blue). It also works with lithium ion 14500 batteries for higher output. Actually a pretty nice light and it was only $11 plus the new LED which was about $4.
At the same time I ordered the Nichia I also picked up a neutral white Cree XP-L HI, which is pretty bright and has better throw than the similar XM-L2 or regular XP-L. The BLF A6 came with a XP-L, so I swapped in the XP-L HI. I almost ruined the light when the spacer between the reflector and LED board fell out (and took about a half hour to find on the kitchen floor). Before I realized the spacer was missing and the LED board had no thermal path to the light, I turned the light on, the LED quickly began overheating and the beam turned angry blue and then faded, but I turned it off fast enough to avoid permanently burning the LED. After I found the spacer and installed it, the light worked fine and the whole light gets hot (as it should). This mod increases the throw of the light but reduces the overall output. Thinking about buying another A6 so I can compare the two, but I have bought a couple of more expensive lights recently and can’t really justify that.
I was a little worried about the LED board in the A6 being a little loose using only thermal paste (the board the new LED is mounted to was a little thinner than the original board). So I bought some Arctic Alumina adhesive epoxy which permanently attaches the board to the flashlight pill and also is supposed to do a good job of transferring heat. In the past I used some stuff that is like latex caulk called Fujik thermal adhesive, but I think it is actually latex caulk. So I wanted to try this other stuff. The same company that makes Arctic Alumina also makes Arctic Silver which has actual silver in it for better heat transfer, but it is very expensive (Arctic Alumina contains aluminum oxide). It sets in about 5 minutes, so I got both the A6 and the ThorFire taken apart and then used a small batch to glue both of their boards down. The Fujik was nice because it did seem to work and you could still go in and remove the board fairly easily. Some people are able to remove Arctic Alumina using heat or cold and popping it loose, but it may not work. My tube of Fujik from 2010 had dried up completely and I was able to get some of the Arctic Alumina pretty inexpensively on Amazon from a company in Georgia, so I had it in 2 days. In the end, I don’t notice much difference. Both lights heated up nicely when they were on High. But the A6 seemed like it would come on bright and then fade in 1 or 2 seconds slight and shift the tint a little towards blue, which indicates overheating. I don’t think it does that quite as bad now. One thing I didn’t do was clamp the LED board down while the epoxy set. It seemed to be stuck on there pretty good and I didn’t want the process of clamping to shift the board, leaving the LED off center from the reflector. Permanently. Since I had them well-centered I didn’t want to mess that up.