dye or paint to make lego parts fluoresce

[Juxtapoisson]

I need to make a part fluoresce under a black light.  It is not available in a fluorescent colour.

I have a lot of leeway.  The part aims to be black or pearl gold.  If the coating alters the colour somewhat, that is fine.  Also, I can consider some other lego colours (that the part is available in), but those two would be best.

 

So, I am looking for a dye or translucent paint that can be applied to lego bricks and that will fluoresce under a black light.  It shouldn't be very thick, I want to retain the physical detail of the piece.  I would prefer the fluorescent colour to be yellow/green ish.  But I will take what I can get.

It doesn't have to be permanent.  If it rubs off easy, that's manageable.  But it has to work when dry.

 

Does anyone have any leads they would share?   Please and thank you.

Wild suggestions you have heard of but not seen are welcome.  If you have first hand advice please include (if known) if the black light used was in the high end (390nm ish) or the low end of common black lights (360nm ish).  The 360nm has less visable white light (and is more expensive), but again, I'll run with what I can make work with out pulling my hair out (I haven't bought the black light yet)

 

I happen to have a gallon of this:

https://brightdyes.com/tracer-dye/fluorescent-yellowgreen-dye/

Which though yellow is (like food colouring) dark orange in it's concentrated form.  While it does discolour legos, the flourescent property doesn't seem to work so far.  I have tried concentrated and diluted dips.  As well as mixes with white glue (I have access to a black light for tests, but not for the real project).  I feel like I could make this work.  But as it's just this once, and I'm tired of the experiments, I am ready to buy a paint or dye that can do the job as-is (or with recipe). 

Please note: Glow in the dark paints usually don't fluoresce under a blacklight (they do super charge, but that's not a solution to my situation). 

 

 

[jam8280]

Did you ever find a fluorescent coating both thin enough and bright enough?

Guessing that you haven't based on my own experience with blacklight builds using the 4 brightly fluorescent LEGO colors (trans medium blue, and trans neon yellow, green, and orange). The perceived brightness of a given spot seems to vary directly with the number of emitting molecules -- say, of trans medium blue pigment -- along the line of sight. To  get comparable brightness, your very thin coating would therefore need an emitter concentration many, many times that of fluorescent LEGO plastic. Seems unrealistic.

 

Edited December 15, 2020 by jam8280