Your assumptions are false and inaccurate. Ive already been down this road with several manufacturers trying to profit on this bad/potentially dangerous marketing idea. So I’ll copy/paste & mod my reply here:
I was a production manager for a precision high tech/high volume metal finishing company (where daily production volume is measured in tons of finished material and in thousands of pcs). FACT: powder coating aluminum, even down to the minimum acceptable thickness spec, will at least double the thermal retention capacity. This isnt false conjecture, and I have nothing to gain or lose by stating fact.
Background: In proving with aerospace engineering teams while powder coating aluminum material on a constant speed precision industrial automated line, several processes required a precision calibrated cool-down cycle before proceeding to the next reheat station in the production process. The line speed was automatically adjusted to maintain a precision target temp. From the data recorded (which is necessary to maintain and prove the production standard), bare aluminum cools at least twice as quickly as powder coated aluminum. This is also true (to a lesser degree) of black electrostatic applied paint and various wet coatings applied at only 35-40 microns (super thin). Dark colors typically radiate heat more quickly than lighter colors of the same formulation. We also experimented with custom formulations containing “micro iron balls” to help disperse heat, ala SR-71 finish type coatings.
So why is powder coating a problem with the lights your intend to coat and at the power levels you just stated? A typical C8 flashlight driven at 3A will get hot enough to burn your hand if left on in high mode. If it doesnt, it lacks a sufficient thermal path from the emitter to the host. Once heated, removal of the battery at that point will also quickly tell you the battery is VERY HOT to the touch… which greatly increases the chances of a cell explosion.
As a re-seller of flashlights, especially the Convoy C8 flashlights and similar (latest version with integrated shelf and 3A 8 x 7135 driver, XML2). If left on in high mode, several have failed in the field, because the heat build up is so great that it desolders the emitter from the MCPCB!… which requires a tear-down and reflowing the emitter back to the board). Sometimes it only melts the solder from the wires, but this isnt as common. This happens to roughly 1 in 11 flashlights. None of these lights are shelf queens and are heavily used by those who purchase. Tube style lights have far less surface area to dissipate heat, which is far more of a problem because they will conduct even more heat to the cell. A tube light driven at 2A will run far hotter than a C8 driven at 3A.
As has been proven dozens of times in just this forum alone, driving an emitter (even at moderate levels within MFGR specs) without a proper thermal path, severely decreases lumen output (which is also the case with plastic lights that have been tested here). The only good thing about plastic lights is that they do not transfer heat to the cells, which lessens the chances of an exploding lithium cell. Heat also kills lumen maintenance (mfgr. rated life of the emitter as measured in hours)., not good.
This has nothing whatsoever to do with the subject, but since you mentioned it: SOME brake calipers engineered for street applications are finished in electrostatic powder or wet finished “paint” (which I have processed several thousands for major OEM’s). It is for aesthetics and ease of cleaning, not performance. Non powder coated alloy calipers dissipate heat far more quickly than powder coated ones, which is why purpose built racing applications are typically never powder coated.
With this in mind, intentionally doubling the thermal load of a cell potentially jeopardizes the safety of your customers. Regardless of how appealing the color might be to the user, overheating the cell can be very dangerous and should be avoided at all costs. I hope you’ll put aside the thought of your grossly inflated asking price for a moment, and reconsider the potential consequences of what you are attempting. Is it worth increasing the chances of your customers turning their (already hot running) stock flashlights into potential aluminum fragmentation bombs? This is exactly what you are accomplishing here. I havent even mentioned potential litigation from such an outcome, should a cell rupture.
- Please dont build and operate a small flashlight and allow it to run @6A until cell depletion, even while using a bare aluminum flashlight host. You will overheat the cell.
- Please be responsible and operate your cells no higher than the max allowable temps specified by the cell manufacturer in their data sheet. Less temp is far better for safety and the service life of the cell.
Good day.