Another day another Emisar D4 mod. 
This time, I added a simple metal switch button.
The goal was to do as simple a mod as possible, with the idea that other modders might give it a shot. I got the idea for this after doing my last mod with a lighted metal switch button on the D4. Unlike that last one this one is pretty straightforward.
Tools and parts needed:
- 1mm thick high-temp silicone sheet. Available at Amazon for $13.
- Scissors
- a small hand file
- tin snips (metal cutting scissors).
- steel wool
- super glue - I highly recommend Fiberfix optical super-glue for its ease of use and instant results (it cures instantly when you shine the blue led built into the applicator). Also available at Amazon, but not cheap.
- Plastic activator pen for super glue - I got this from a package of super glue advertised for plastics. Not sure if it works with other super-glues but certainly doesnât hurt.
- a screwdriver, victorinox mini knife or other tool to help in removing the switch boot retaining ring.
How to do the mod:
- Step 1: Remove the switch retaining ring and remove the stock button boot. On a number of D4s, I can lever the boot off with the screwdriver at the end of the nail file on a Victorinox mini. Bring the file in from the side and dig it into the boot under the retaining ring, then lever it up. However, this didnât work on every light. On my most recent D4, the ring was stuck and I gave up before seeing if it would break my knife. Itâs possible that a twisting action would get a better result but would be more likely to damage the stock boot.
- Step 2: cut a circle of 1mm thick high temperature silicone sheet with the exact same diameter as the stock button boot.
- Step 3: cut a circle of aluminum sheet for the button. I used 0.016â aluminum sheet cut with tin snips and then filed with a hand file into a nice circle. File down the circle until it is about 1mm smaller than the retaining ring on all sides. Chamfer the upper edge so there is no sharp edge and then run steel wool over the edge to smooth it out. Rough up the bottom with an etcher so the glue will grip better.
- Step 4: make a piston on the bottom of the silicone sheet. The barest hint of a piston is all thatâs needed. I penned on the plastic activator, waited one minute, then put a single drop of fiberfix super glue right in the middle. I used the light on the glue applicator to instantly cure the glue.
- Step 5: place the silicone circle into the switch socket of the light, piston down and test for fit.
- Step 6: place the retaining ring back into the light with the silicone circle as the new switch boot. I found the easiest way to get the ring back on was to place it in position with the head upside down over a small anvil, then press hard with my hands to push the ring back in.
- Step 7: Glue the Aluminum circle onto the top of the silicone circle. Carefully center the aluminum circle within the switch retaining ring before gluing, then use the plastic activator and fiberfix. When I first did this I noticed the silicone was bowing up into a dome with the boot sitting on top. I removed the new boot and determined the silicone circle was slightly too big so trimmed a bit off at the edges. I then used a toothpick to apply more fiberfix glue all around the edges of the metal button so there was no longer any gap.
Result: A fairly good looking metal switch that looks like it came with the light and sits flush with the stock retaining ring.
This entire project took me just half an hour. It was really quick.