I wouldn’t use protected cells in it, for that reason. The worst that could happen with un-protected cells is that the light comes on. With protected cells it could direct short one or both of the cells.
The spotty continuity is probably due to some areas having thicker anodization than others or some of the tube was not concentric so only the high spots ground off for a uniform tube diameter and left those areas without ano.
It’s not a Huge deal, just something to be aware of. (unless of course you’re using protected cells and then it COULD be a Huge deal!)
At the end of the day it’s no real difference from the battery tubes I make for my scratch built lights. None of those have any ano at all. (I also never use protected cells)
Richard sells a Kapton tape (or used to) in a 2” width, this would be ideal to put a layer around the cell to act as a very thin wrap and give some tube separation. The Kapton tape is really very very thin but strong. Worth checking into maybe.
Interesting. Any sign that they may have machined the inside of the tube after the ano was done? To true it or to fine tune inside diameter? (anodization can cause dimensional growth that can sometimes be unacceptable.)
To my knowledge, none of the top brands make a protected cell. So the protected cells all have aftermarket IC’s added to them. I’ve heard that some will strip the original wrapper and apply Kapton under the protection strip, then another layer of Kapton, then rewrap the cell. These are the thinner ones. If they leave the original wrapper on then indeed they do grow in diameter with double wraps, the strip, and a couple of strips of Kapton tape.
Tube on your left is factory, tube on right is after honing.
Interesting, I just checked my 2nd Clear L6, and it is much, much worse doing a continuity test (virtually all around the circumference with breaks). Note the inline milling marks on the factory tube.
Now that is weird? Looks like Extrusion or Broach marks to me!
My (2) right off the machine bare naked L6’s have radial tooling marks, and not straight thru either, like it was bored/gun drilled maybe reamed from both ends, I can see the tooling transition marks inside!
I have seen this done on Trunion Machines were opposing spindles come in from both sides, while the tube is clamped. Like on axle tubes and PTO shafts.
Keep in mind that here in the States you’d be darn lucky to find a machine shop that would turn a battery tube, no anodizing, for the price of this entire light. Just sayin…
More data points, the Clear L6’s are also measuring continuity on the exterior, from tail to head, randomly. I get similar results on a clear C8 (inside and out). Black one is generally good.
Looks like Clear anodizing process is on the lightweight side. Although outside still looks good.
Cheers man, and thanks for being here bonking heads with us to try and solve this.
Far as I myself go, just widen the tube. If someone complains about rattling, it’s just a matter of wrapping a paper sheet around the cells. I did it all the time when I had 2xAA torches, and even a simple supermarket receipt does the job if you wrap it in the middle where the two batteries meet. Simplest mod ever.