Lots of nifty you tube videos on etching blades ..
I just like the sound of ...road salt and a battery charger :P
I’d definitely go with one off the first three options. They sound a lot more environmentally safe. LOL
Following on from the previous posts , here is a brief explanation on how I etched an item, in this case a dog tag , this procedure is of course also valid for etching steel or stainless flashlights,
A piece of mild steel with some surface corrosion
Shaped up, wire brushed and degreased
Without getting nasty fingerprints all over the metal, the design is put on using a sharp point and a puddle of nail-varnish. Nail varnish is not easy to draw with as it’s very viscous but with some patience it’s possible to achieve good results
Design complete and then left in the sun for a couple of hours to dry well
Screw fitted for attaching a short wire. Or you can simply stick the end of the wire to the item using gaffer tape. All the bare metal immersed will get etched so mask off the bits you don’t want etched with tape or nail varnish
The etching pot, plastic. I keep a bucket of half full of road salt for use during the winter and top it up with water so I can sprinkle brine on icy bits,so the brine I use is very strong. Put some road salt or cooking salt in boiling water until it won’t dissolve any more. The pot of brine I’m using has been going for a couple of months, now and then I just pour the brine carefully off the sediment and then top up with more brine. Clipped to the side of the pot is a piece of copper pipe, slit and opened up and the top crimped to the edge of the pot so it stays still. I think copper is ideal but expect brass or stainless would do as well.
By the side of the pot is a piece cut from a plastic bottle and with holes drilled in, this is clipped to the side of the pot and shields the copper plate so that nothing can short circuit against the copper. The plastic is clipped to the pot using plastic clips.
This is the wiring arrangement, the short length of wire is attached to the positive (red) clip of the 6 amp battery charger and the wire is tied to a piece of Titanium rod so the dog-tag will hang at a good height in the pot. I use Titanium because I have some and it is non-conductive so there is no chance of an accidental short-circuit, a stick would do. Other amperage battery chargers will do or you can even use a car battery or a D battery cell. The negative battery charger clip (black) is attached to the top of the copper strip in the pot
Here it is connected up and etching, The dog tag is in the centre of the pot. There are a lot of tiny bubbles coming from the copper strip. The brine becomes murky very quickly and the surface gets covered with a horrible scum, don’t drink it. As the metal etches there will be metal particles covering the thing you are etching and these particles will inhibit the etching process, so slosh the item up and down in the brine every few minutes to shake the sludge off or lift it out and give it a careful brush off with a very sort brush. If you are not careful the nail varnish will slough off, take care. I tap the Titanium rod on the side of the pot and this works for me. If you don’t clean/shake the sludge off every few minutes then some parts of the metal will etch quicker than the rest. After tapping I rotate the rod 180 degrees to present the other side of the metal to the copper strip. I don’t know if this makes any difference, but why not!
Sludge, leave it overnight and it will drop to the botom, it’s not necessary to clean it out every time
The time you leave it etching depends on the electrical supply, amperage and the depth you want the image to be. This is after 30 minutes, rinsed off with water, the nail varnish cleaned off with SWMBO’s nail varnish remover and the metal given a good wire brush
And after colouring with gun-blue and given some bee’s wax polish, job done and it worked out well 
Nice work and a very good demonstration/explanation.
Is anyone else thinking about looking for stainless hosts to give this a try on for a real custom build? :bigsmile:
That first light looks like something from a Sci-Fi movie or Star Wars. Nice!
boyo17 , have you tried etching any aluminum with the copper sulfate + salt yet ?
I have a couple of aluminum flashlights that might need some customizing ...
EDIT : Oh , by the way -
Still bent to make some port he knows not where, still standing for some false impossible shore,,,,,
Aluminium is one of my least liked metals mainly because it does not gain a patina that gets better over time. I might try it some time if the right object presents itself.
Absolutely , I bet you are one of the usual suspects 
If I were to try anything like that I’d probably end up in hospital. :Sp
Joking aside, beautiful work. Thumbs up!
Wow, the result of etching a knife looks really good. I like the result and that you use no acid. Maybe I will try this in the future.
Wow! That is SO cool. I absolutely love what you did with that ED01!
Very cool. Keep up the awesome work!
I’ve got a Trustfire mini 03 to modify but am thinking about what to do with it, meanwhile I’ve made some new scales and pocket clip etc. out of Titanium, the Swiss army Recruit looks good as far as the finish and colouring I’m getting, so I know that Ti will be on the flashlight
