Arc4+ reflector ?

I recently bought an Arc4+ off of ebay. The light is basicly in good condition. However someone has had a go at wiping or attempting to clean the reflector. Well we all know the outcome of that attempt. The reflective qualities are now somewhat less than they were. Does anybody have any ideas on how I might restore the reflector to its original luster. Perhaps there is someone that has faced this problem before. Is the reflector merely highly polished alluminium with perhaps a clear sealer over it to prevent oxidation? Or is there some kind of silvery shinny paint like coating applied? It would help to know what I'm dealing with here before I continue.

Another note off reflector topic. This light's serial # is not listed as a second yet there is a curious cosmetic flaw that strikes me as odd. There are 3 belt clip mounting holes. As a result of these 3 holes there are 2 possible positions that the clip could be mounted. One would think that such a boo boo would have landed this light in the seconds bin. Not that that matters much now.

cheers,
zwf

There was a HDS that had 3 holes as well...
Strange.

ZuluWhiskeyFox,

Restoring the reflector without removing the electronics module first will be difficult. Removing the electronics module without destroying it is very difficult because it is epoxied in - with several unsuccessful attempts being reported.

The reflector surface on the Acr4 is a 3 layer surface that is very susceptible to damage. Any paper product will scratch the surface. Even gently applied cotton can scratch the surface.

A scratch is a roughening of the surface that scatters light - which is why a scratch appears white. It is theoretically possible to apply a thin clear coating to the reflector that will fill in the microscopic roughness that is the scratch and thus make the scratch disappear.

It is interesting to note that hard brittle surfaces scratch worse than relatively soft surfaces. The hard brittle surface easily generates the micro-roughness which scatters light while a softer surface tends to produce a fairly smooth dent which scatters much less light and therefore does not show a white scratch. This is how many anti-scratch coatings work - such as the MR-10 coating used on Lexan (polycarbonate). The coating is actually a fairly soft silicone coating.

The problem with the early reflective coatings - such as were used on the Arc4 - is that the protective surface was hard and brittle and thus easily scratched.

So to repair the finish - assuming only the top layer has been damaged - requires applying a new layer on top of the old layer. The new layer must be compatible with the old and must not damage pure aluminum. The new layer should go on thin and easily wet the surface of the old layer. You can probably use a soft fine model paint brush to apply the top coat.

The material for the top layer should be water clear, harden by polymerization and not contain any solvents or release anything that might corrode aluminum while drying. A UV-cure product might be a good match for this project.

The three mounting holes in your flashlight is a machining error. It probably happened during the manual set-up part of the job and the machinist neglected to remove the parts from the lot and no one down the line noticed the flaw and pulled the part. I have seen anything from 0 to 4 holes in a head.

Henry.

More clip positioning options sounds good to me.
Why not drop in a tritium vial in the extra hole?