Hiya all. I had a question about colored incandescents .


This below image by @LAllenLighting depicts a GLS lamp coated with an opaque glaze/paint from the inside.
Aside from GLS lamps, this kind of color application can be found in various shades (yellow, orange, green etc.) in various types of lamps from pygmies to tiny globes and of course GLS lamps:

(click to enlarge)


Not so common, however, is the type of incandescent coated from the outside with a translucent lacquer.
This type too can be found all the way from pygmies to small globes and of course GLS lamps, but the filament is actually visible when powered up.
I came across this type of coating on a pygmy lamp but I haven't found the time to upload the photos. In it's place, here is an example by @LightsAreBright27, almost identical to my lamp in the coating used:

(click to enlarge)

---

Here are my questions about the second (translucent) kind of coating:

How are these lamps made commercially? What is the kind of liquid they are dipped into, how is it made and is it easily available or even possible to synthesize from other easily available chemicals?
I assume the liquid has to be heated for this to work, so at what temperature would it be feasible?
What is the chemical compound used for the blue color? I have only picked blue cause it is my favorite incandescent color but I'd still be happy to learn about any color for that matter.
How realistic is it to coat either a GLS bulb or any smaller lamp (like a pygmy) at home with such a lacquer to get that blue hue?

Anyone?
@James?

I am not aware of what is actually used in lamp industry, but for thermally stable dyes in blue and green, different phtalocyanine dyes seem to fit well. These are very robust molecules, capable of surviving up to 500C. Maybe, also very finely disperse powders (to avoid milky appearance) of classic inorganic blue pigments like prussian blue or cobalt blue will work.

You of course need a thermally stable lacquer. 2-component silicone will likely work. Also may be something more specialized like high temperature polyurethane or polyimide, which are used in high temperature wire coatings.

Hmm, cobalt blue plus silicone seems like something that won't be too hard, it's worth a shot. Although I'd love to try the professional methods, it's just way too expensive and not possible without a factory