If you use lye (sodium hydroxide) there are a few things to be very aware of. If you have the dry type of the chemical ALWAYS add it to water. NEVER the other way around. Also start with cold water. Dissolving sodium hydroxide in water causes an exothermic reaction; heat is produced. Water into dry can create a steam explosion the exothermic reaction is that strong. There are also fumes released that are not good to breathe. The sodium hydroxide solution will burn skin on contact; very bad for the eyes. I use sodium hydroxide in making bar soap. I wear heavy duty rubber gloves and eye protection. I always mix outside and let it cool before bringing it into the shop. Do not mix in an aluminum container; therewill be a chemical reaction. Use glass or stainless steel. FYI, crystaline forms of drain cleaners that foam and bubble usually contain aluminum fines just to make the bubbles so the consumer thinks it’s working good. Pure marketing, the bubbles serve no useful purpose.
Strange how something so nasty makes great soap when combined with the proper amounts of fats or oils.
If you leave the aluminum light in the solution too long the aluminum will be eaten away. In fact I think when used for removing anodization it will leave the aluminum with an etched surface. Not shiny in other words. I am not sure on that. I have never removed anodizing on a light but was curious once about how caustic it was and tried soaking a piece of bronze anodized aluminum window frame. Yup, it works and the aluminium was dullish. I don’t recall if it was pitted, satin, or whatever.
If you clean the flashlight very well beforehand and keep the flashlight or lye solution in motion, the anodising layer is removed very evenly, and there is a quite distinct moment that all the ano is gone and the aluminium is not being eaten away yet. If you rinse the flashlight/parts (last time I dunked the complete flashlight in the lye) at this moment, the surface can be quite smooth and be polished fairly fast. The longer you wait the more etched the surface is.
Last I checked one could buy Sodium Hydroxide crystals on Amazon.
Also been having thoughts on an EE X6. The Lye solution will get into the deep fins on the X6. HMMM again… I have an Ultrasonic cleaner with a heater, bet that will make short order of de-anodisation. As you can see in this pic, same S2+, de-anodised, but with a brushed finish, before I polished it. Brushed look really showed scratches easily.
There are still darkened areas, kinda yellow, in the knurling. I think that a second dip in the ultrasonic with some dish detergent and touch of Lemi Shine (citric acid) may be a no touch, strip and clean. Should get any discoloration out of the X6 fins because Dish detergents have metal brighteners and the citric acid does the same. Will neutralize the Lye also.
Another thought I have for the X6 was to only sand the high or flat surface areas, leaving the flat black in the fins and knurling. May look cool and if I FUD it up I’ll just strip it clean. I have a couple more X6 hosts on the way, we’ll see what happens when they arrive. Plans for both were XP-L HI single and triple.
Thanks MtnDon. You did a good job explaining the hazards and how to avoid injury. Better than I could. Be careful.
With the solution I started with one tablespoon to a Quart of water. I have a 1/2 gallon that I have been reusing for some time and not only on flashlight anodize removal. Strengthen the solution 1/4 Tbs at a time if your not satisfied. Warming the solution makes a huge difference in its effectiveness. I have been using an old ceramic coffee cup as it holds the dismantled parts of the lights I have done. I can also just heat that cup of solution in the microwave for a minute to warm it before using. Keep your solution in a plastic milk jug or glass jar. You can reuse it Many times.
Did some more tweaking of the Atom triple XP-L HI today, now the momentary tail switch can be activated while the light is in the magnetic keyring holder, which is handy.
most oven cleaners dont clean ovens very well either. This solution would do that better too.
do a cheap ebay light first. Just keep water pan near to rinse the light. Dont use your bare fingers to fish out the parts from the solution. Solution cold is relatively mild and is slow to react. Warming it makes all the difference. So if a cold solution works its too strong, add water.
Hey PD… in an XM-L2 I love the 4C, but in the XP-L I am really liking 5A3 and in the XP-L Hi I really like the 5A2. I have finally really found the sweet spot for me, when not using a 219B SW40.
OK, I guess this one is not quite finished and this is a teaser. There will be 7x dedomed XPL V6 1A emitters behind narrow TIR optics. I estimate there will be 8000+ lumens OTF and 130+Kcd.