Stripping and re-anodizing a E-to-C adapter for LED module compatibility

[yazkaz]

Have handled various makes of such adapters and know one critical thing: the adapter unit must not be fully anodized all-round, or the resulting piece will not be compatible with LED drop-ins (unless with auxiliary copper ring installed below). As such, the internal socket surface (excluding the anti-bore) must be left bare for effective electrical conductivity with LED module setups. But the question is, should the internal threads (that connect to the E-head side) be left bare as well?

Asking because I have two Surefire original E-to-C adapters (pulled from new LU60a) which I'd like to strip and re-anodize to LED-compatible specs. To be precise, I'm planning to strip the original HA3 hard black, mask the module socket's internal walls, then re-anodize in hard clear (for compatibility with wider range of OD-colored E-systems). Should I tell the workshop to carry out additional steps, such as masking the internal threads and nickel-plate the bare internal socket surface?

Any take?

 

[fivemega]

should the internal threads (that connect to the E-head side) be left bare as well?

Not the inner threads but surface that touches to lip of E body on head side must remain bare metal for electrical conductivity.
You also need to mask inner part of adapter where module sits.
Normally, this is done with paste material which gets rubberize after drying similar to pliers handles then after reanodize, this masking can be removed by acetone.

 

[yazkaz]

Not the inner threads but surface that touches to lip of E body on head side must remain bare metal for electrical conductivity..

That's strange. When I look into the socket area the said contact "lip" from the e-body seems to pass through and is thus visible in my face. Only the side threads touch the e-body's head threads.
BTW I don't have a proper (SF original) e-body to test, so I use PEU's Pine body instead. I also use LF's E2C adapter for testing, which comes with bare internal surfaces from inner threads to whole socket (counterbore), up to the slanted (countersink) top.

You also need to mask inner part of adapter where module sits..

Yes that's the internal socket wall I was referring to...

Normally, this is done with paste material which gets rubberize after drying similar to pliers handles then after reanodize, this masking can be removed by acetone.

Yes, but from last year's experience it seems that the workshop hadn't cleaned those masked surfaces effectively, leaving the surface with minor dull and perhaps even a tinge of rubbery feel. In the end I had to use DeOxit (D and Gold) and Flitz to restore those bare surfaces...

The question is, should the bare surfaces be plated with nickel for better electrical conductivity? And, is that an expensive process?

 

[yazkaz]

Well it seems that SF's own C2E may have more problems of its own. Using the PEU Pine body and LF's own E2C adapter I did a conductivity test only to find that, when installed, the bare socket wall is electrically NON-conductive. Back to SF's own E2C, it seems that the only way to make it work with LED modules would be the small waved beryllium copper ring (sold by Oveready) sandwiched between the top battery and modules' lower contacts...

So I'm not sure what's going on. Will leaving just the inner threads (on the original SF adapter) bare do the trick? Or, there's something wrong with the thread's height, as well as the design of the module socket that matter? With SF's adapter the socket seems to be of traditional counterbore design but with LF"s adapter there's an additional countersink area deep down the counterbore. Not sure if this might affect the chances of electrical conductivity?

 

[DrafterDan]

did you de-anodize the surefire C2E adapter? Anodizing of any color is non-conductive. I find that when working with different products (like a PEU body and a SF adapter), check everything for conductivity, apart and together. There may be a gap of maybe only a couple thousands, but electrons don't like to jump at the voltages we work with.

 

[yazkaz]

There may be a gap of maybe only a couple thousands, but electrons don't like to jump at the voltages we work with.

I suspect that too, could be that the inner threads are slightly taller than on the LF adapter such that Oveready's copper ring is needed to fill that little gap. And if that's true, then even just stripping the inner threads only (on the SF adapter) may not help. Anyway more testing is needed to confirm that.

 

[fivemega]

18350 & 18500 E head, E tail bodies

26670 E Body

TS SS 18350 18500 18650 Bodies

1x18650 & 2x18500 E Bodies

E Head, C Tail.

D36 bodies
If you look at any of above bodies, threads are anodized but very end lip remained bare metal for electrical connection.
Obviously, male thread of body is slightly longer than female thread of head or adapter to make sure electrical connection is good.
If you look at completely assembled and working genuine E flashlight, you will notice a very tiny gap between head and body neck which is normal and necessary therefore, this is proper way of electrical conductivity and we don't rely on threads for this purpose.
If $urefire has bare threads, that's because they don't want problems caused by anodize buildup.
Remember, if anodize buildup is only 1 mill per surface, then you will have total of 4 mill fatter threads. Same will apply on female side.
$urefire use kemfilm on threads and contact area. Much cheaper and very tiny buildup.
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The question is, should the bare surfaces be plated with nickel for better electrical conductivity? And, is that an expensive process?

That would be much better but not necessary.
Plating material (nickel) buildup may be problematic on threads also you can not anodize on nickel plated surface.
However, it is possible but involved with lots of work therefore very expensive.
Bare aluminum must be completely masked except contact area then nickel plated.
Masking removed completely and rewash the part. Then carefully mask nickel plated area and after anodizing, remove masked area.