Malkoff/6P heat conduction

I was thinking about all these cheap-looking fixes like tin-foil,copper tape, ect.ect.

I was wondering about a good fix. Like something akin to JB-weld that could be poured around the LED that was a GOOD conductor and had similar expansion rates that would truly mould the LED module contour (albeit permanently) to the 6P body. What chemical/putty/whatever would fit that bill, has anyone experiemented with this?

In the 6P, such modifications are not necessary. The module has sufficient heatsinking as-is.

N/Apower said:

I was thinking about all these cheap-looking fixes like tin-foil,copper tape, ect.ect.

I was wondering about a good fix. Like something akin to JB-weld that could be poured around the LED that was a GOOD conductor and had similar expansion rates that would truly mould the LED module contour (albeit permanently) to the 6P body. What chemical/putty/whatever would fit that bill, has anyone experiemented with this?

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Even just putting the foil on is unecessary, it's mostly to fix contact issues, improved heatsinking is just a nice side effect. If we had high output LED's that could handle 10+ amps then there might be some need for that level of heatsinking, as it is even the MCE and P7 M60's work fine without modification.

In my case it's an M30, and I am sure that the M60 gets hot too. Anything you can do to add to heatsinking is a good idea. There is not much metal to metal contact between the M30, M60 series Malkoff's and the SF body, and any additional heatsinking will at least lead to longer regulated runtime, and the LED will love the added thermal relief. I am not sure about the thermal properties of JB Weld. We should not po po inhanced heatsinking when driving LED drop ins, even the brass heatsinked M60.

Bill

Would scraping off the anodizing on the tail/head threads of my fivemega body improve the heat conduction/electrical conduction? I have an M30W in there, and I was wondering if that would help.

Thermal management with these drop-in modules is something I've wondered about...

First of all, brass is not an ideal metal for a heatsink, because the thermal conductivity of brass is about half that of aluminum (and aluminum has a thermal conductivity roughly half that of copper or silver). Also, the Malkoff module contacts very little surface area in the body of the flashlight, and really doesn't have a thermal path to the head of the flashlight either (due to the sticker around the head of the module).

Guess it depends on the alloys used in the brass. Gene's brass sink heats up quickly. He also uses some good thermal epoxy to pot circuit. We are not seeing LED failures due to heat with his drop ins.

Bill

Anyone think about wiping some of the module with Arctic Silver or such? Where is the most contact between the module and the bezel anyway?

I have been thinking on this also, and wondered if I used the non permanent thermal trasfer paste (that we use on work in thermowells on our RTD's and thermocouples) may be good to put a little in the head around the module, but I bet it would be a real pain to clean out, as it could make its way into everywhere ( even thought it mentions in the one I link to low Creep), including the module reflector, as it is not sealed.


Have thought of this in building hotwires also where it may help more.

I also wondered about blue tac.
If bluetack is not tacky I put it on the radiator, and it heats up and gets all sticky...it would be easy to mould into the module and not messy, and easy to remove and clean up, but it depends if it acts llike a blanket, or a conductor. :thinking:

I would think mixing up some thermal epoxy might be a good solution. Once it hardens, ur done. Run your malkoff through a set of batteries to make sure you didn't get a bad LED (happens to the best) and then epoxy the bad boy in there.

I've actually thought about the JB Weld(even went and got some), and the thermal epoxy(already have some).
Those would work, but what I thought of doing was using the module as a mold for the JB Weld, maybe with a layer of Saran Wrap around it, or just pulling it out after it had shaped the JB Weld and cleaning it, so other versions could also be used in the same light.
I ground down the base of a M60WLF so that it fits flush in my C2. The module makes contact all around the front of the body, plus at the battery tube as a result. A couple strips of foil make the body of the M60 friction fit, too. With a "L" model that's only drawing 270mA from a pair of R123s, heat probably wasn't going to be much of an isse, anyway.
I really think this is big-time overkill(less so for a MC-E), but may give it a shot one day with the body I use a M60W in. I want to be able to remove that drop-in in case it some day needs warranty replacement, though.

I can't see the point of worrying about the heat sinking ability of Gene's products because Gene would never produce and market a product which was liable to fail from a poor design. Gene's business and lively hood depend on the reputation he's already built up for making reliable and long lasting drop-ins. If there were reports on here or elsewhere of premature failure of any of his products then I could understand your concerns but that is not the case is it? Besides Gene backs his creations with the sort of after sales service that many other manufacturers could only dream about. If it breaks he fixes it...period. I've had a couple of his units for a while now with no problems being run for protracted length of time and no signs of LED degradation or other problems. If you are concerned Gene's products aren't up to the job why don't you ask Gene about it? I'm a bit puzzled by why you would buy something that you don't think will last?

I don't question Gene's heatsinking solution. I just look at getting better metal to metal contact with Gene's good heatsinking solution, his brass heatsink. No harm there, and that is what CPF is about, people looking at products and finding ways to improve them, for themselves, by offing up modification ideas, and experimenting.

Bill

I do agree that there is no harm by looking at ways to improve things and meant no offense. However, I am simply posing the question if it aint broke why fix it? Of course as I said it wouldn't do any harm to ask Gene if he thinks there is any benefit to these ideas or even if he thinks it necessary?
Of course I think I should add that I'm an unashamed fanboy of Gene's products!

dougie said:

Of course as I said it wouldn't do any harm to ask Gene if he thinks there is any benefit to these ideas or even if he thinks it necessary?

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When I asked him recently about using some sort of thermal compound between the brass and the light body, he was very unenthusiastic. He seemed to go along with the use of aluminum foil if necessary to take up space.

Maybe its is me just wanting to "pamper" my M30. Unless I am doing a runtime test I don't use my M30 long enough for heat to be a real issue. No need to ask Gene.

Bill

My 6P is equipped with one of Gene's handmade M60 drop-ins. So far, no issues at all with heat conduction; and I seriously doubt that there ever will be. The M60 is built to function properly in a Surefire C-series bezel. Only time I've seen CPFers use tin-foil or something similar, is when they want to use their Malkoff's in a different type of bezel; and the fit might be too loose.

dougie said:

I do agree that there is no harm by looking at ways to improve things and meant no offense. However, I am simply posing the question if it aint broke why fix it? Of course as I said it wouldn't do any harm to ask Gene if he thinks there is any benefit to these ideas or even if he thinks it necessary?
Of course I think I should add that I'm an unashamed fanboy of Gene's products!

Click to expand...

+1,

I am the kind of guy that "wants one that goes to 11" so-to-speak.

Gene makes a damn fine product, noone has EVER questioned that that I know of (and certainly with no basis). However, everything can be improved upon. If you are standing still, you are moving backwards.

I would not use any non electrically conductive epoxy. If you do a good job in making a nice smooth film around the bulk of the module you may have just done away with your electrical ground return path. If you don't want copper foil tape, the thermally and electrically conductive mounting pasts may be the way to go but there are questions as to what will happen I am sure you have not thought about.

1: Will the epoxy slowly outgas from heat and fog up the inside of the lense with a film that might ruin it thereby making a perfectly good flash light less adequate? Most epoxies outgas solvent as they cure and afterwards if the were not cured at a nice high temp to outgas in an open environment initially.

2: The electrically conductive pasts are typically made of something with Silver. Will you create a galvanic cell that pulls Aluminum out of the host wall and dissolve it into the silver epoxy with electrical current? Silver is the more noble metal and the Aluminum is the one that will corrode, dissolve into the Silver. You might eventually cause the inside wall of the host to become a resistive path. Thereby defeating the very goal you wanted to accomplish. Less long term reliability and performance.

Something to think about. Copper foil tape works well for me.