I've seen the video posted here a few times. Probably in the LED conversion thread... Regardless, yes, the video does give a lot of information. I actually used it to do my dash because I got hung up on a few things.
Acetone worked perfectly fine for me. The green tint is a film sparsely applied to the back. As far as I can tell, the actual gauge markings are a separate layer on the other (outer) side. As long as you stop applying the acetone when there's no green left, I don't see it being really possible to destroy the plastic. I do believe I have some thin spots, but there's absolutely nothing visible in the front
That video uses a [1x] 5050 SMD LED bulb for a 194/168 socket (5050 SMD is the LED size and style). The description states he later used a different type, but the link is dead. adrst (the LED conversion guy) used [5x] 5050SMD LED "towers" for 168 sockets. One faces upwards, the other 4 face outwards on a square tower. This is also how I did it, but I'm not pleased. I've already decided on just making a large array of superflux LEDs and solid core wire (a wireframe, so to speak), but for everyone else, simply masking the top LED of the 5x5050 tower may be enough. I can't promise anything, though.
Then again, many people will be happy whatever it looks like simply because they're blue LEDs, and blue LEDs sell everything.
Tint vs LEDs vs Paint vs bulb cover vs overlays. Each has their own advantage.
You can get LED 168s in any color you want, as long as you want red, yellow, green, blue, pink, purple, or white. Unfortunately, orange turned out to be so difficult to find (because every yellow bulb was listed as yellow/amber/orange), that I went and bought reds and swapped the LEDs myself with a heat gun. If you can solder, LEDs definitely have my vote. Plus, I feel they have a richer color
However, if you can't solder, vinyl tint is probably the easiest thing to do. I would apply it to the back of the clear piece. Maybe glue the edges for added reassurance it won't peel in the heat.
I'd imagine paint would be very hard to apply thick enough to get the color, thin enough to let enough light pass, and even enough to look professional. Maybe use a spray gun and mix the desired paint color with clearcoat?
You can change the entire look of the dash with an overlay/replacement gauge face. You can get a few different full overlays on eBay for $50, or get white-face overlays for $20. They're a little too flashy for me (take a look, notice how many blue elements are forced into the design because just like blue LEDs, blue lines also sell). White faces are a little too obnoxious for me. This isn't a Mustang.
Do they still make colored bulb caps?
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I also gave up on trying to make [size] 3528 LEDs soldered to wires to replace switch bulbs and use the existing optics. I've been having a blast with a Dremel and copper-clad board to make "printed" circuit boards. Headlight switch for example:
(bare board)
I've also started using adjustable voltage regulators and "remote" trimpots (trimpot with a long wire) to match LED intensity between different parts after assembly because nothing is ever good enough for me when it's my own work.