[HN Gopher] How to make colored fire at home (2020)
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       How to make colored fire at home (2020)
        
       Author : squircle
       Score  : 101 points
       Date   : 2024-06-10 12:02 UTC (2 days ago)
        
 (HTM) web link (sciencenotes.org)
 (TXT) w3m dump (sciencenotes.org)
        
       | h2odragon wrote:
       | possibly of use:
       | 
       | https://www.skylighter.com/collections/coloring-agents
       | 
       | https://www.pyrochemsource.com/Fuels-Colorants_c_16.html
        
       | eps wrote:
       | ... and not a single photo.
        
         | cpach wrote:
         | There was an illustration though :)
        
       | dr_dshiv wrote:
       | Don't miss the black flame! https://sciencenotes.org/how-to-make-
       | black-fire/
        
         | huhtenberg wrote:
         | Yeah, that's cheating :)
        
         | croon wrote:
         | That one we'd like to do at home, if I could get my hands on an
         | LPS lamp, there's a lot of wrongly marked bulbs out there,
         | afaict.
        
           | sva_ wrote:
           | Just look in a growing shop. Isn't that what they use?
        
             | genter wrote:
             | No, they used HPS. Although now replaced by LED.
        
               | sva_ wrote:
               | Ah, fair enough. Doesn't seem so hard to find a legit one
               | though. Searching for Philips SOX gets me a lot of
               | results for example.
        
         | hi_hi wrote:
         | Very cool. Reminded me of this post about Sodium Vapour Lights
         | used in old school special effects chroma keying.
         | 
         | https://news.ycombinator.com/item?id=39962615
        
       | nelox wrote:
       | They forgot phosphorus
        
       | dr_dshiv wrote:
       | I'm thinking of producing an "Alchemy Set" for kids. Like a
       | chemistry set, but... more esoteric. I work with these experts in
       | Alchemy from the Embassy of the Free Mind in Amsterdam.
       | 
       | If you are into this sort of thing, any experiments you'd hope to
       | see in the set?
        
         | croon wrote:
         | My daughter (6) loves experiments, but honestly all the
         | chemistry sets and similar we've bought have been quite boring,
         | except for the bog standard baking soda/citric acid/green
         | coloring snot volcano.
         | 
         | I like chemteacherphil on YT, who does a lot of visually fun
         | experiments, many involving fire, and I would definitely buy
         | packaged products of some of those, instead of trying to source
         | chemicals/metals/tools for home (not having access to our own
         | lab).
        
           | alt227 wrote:
           | Thanks for pointing out chemteacherphil, looks like the exact
           | type of thing Im looking for to watch with my kids.
        
           | 7952 wrote:
           | My nephew is into this. The great thing about the bicarb
           | style ones is that he can actually play with the ingredients.
           | And this is what "experimenting" should be. Trying things out
           | and seeing what happens. The fun is finding out what happens
           | when you use the kit in an unexpected way and make a mess on
           | the ceiling.
           | 
           | The problem with the more exciting/interesting experiments is
           | that play has a larger potential blast radius. And
           | understandably adults impose more limits which then leads to
           | less actual experimenting. And that actually makes it less
           | fun.
           | 
           | Because the best experiment is to start with random chemicals
           | and seeing what happens. Not a carefully curated set with
           | predictable results. The boring failure and the unexpected
           | result are all part of the fun.
        
             | 101008 wrote:
             | You are right. You described the difference between a
             | experiment and a recipe.
        
           | TheNewsIsHere wrote:
           | > My daughter (6) loves experiments, but honestly all the
           | chemistry sets and similar we've bought have been quite
           | boring [...]
           | 
           | I had chemistry sets as a kid, and I think I agree with this.
           | As an adult I understand why these sets are boring, and
           | honestly I'd be more likely to play with these sets as an
           | adult. The instructions and guides weren't really very
           | creative and they weren't engaging.
           | 
           | At the same time, the chemistry sets of the (for example)
           | 1950s were absolutely batshit insane and are rightfully taken
           | off the shelves.
           | 
           | It's a shame there isn't much of a middle ground other than
           | finding YouTube demonstrations. Then again I haven't looked
           | for a chemistry set lately...
        
       | CoastalCoder wrote:
       | The article's safety information doesn't mention the possibility
       | of intense UV. Is that a risk with any of these chemicals?
       | 
       | I thought of this because the list includes magnesium sulfate.
       | IIRC, burning magnesium _tape_ generates enough UV that you
       | should have eye protection.
        
         | perihelions wrote:
         | I don't think there are any combustion reactions here (besides
         | the source flame), since these are already fully oxidized
         | salts. It's only internal electronic transitions of the metal
         | ions.
        
           | CoastalCoder wrote:
           | I don't know much about chemistry, so I don't really
           | understand the significance of that.
           | 
           | Is the idea that there's no highly energetic reaction, and so
           | nothing to produce the energy levels needed for intense UV?
        
             | mecsred wrote:
             | Not my area of expertise but I believe the explanation is:
             | the radiation profile is blackbody radiation proportional
             | to the heat of the flame. The metal salts color the flame
             | by absorbing light and re emitting it according to their
             | electron transitions. However the don't add additional
             | energy so there will be no UV light, since the original
             | flame doesn't produce (almost any) photons that energetic.
             | Magnesium burns much hotter and emits uv directly from
             | blackbody profile.
        
               | marcosdumay wrote:
               | It's a small fix, but the original flame emits mostly UV
               | light. It's just almost harmless low energy UV.
               | 
               | The issue with magnesium burning is that both the UV
               | light is way more energetic, and it tends to also be very
               | intense.
        
         | kragen wrote:
         | no, because the fire is too cold
        
       | daralthus wrote:
       | One of the magical experiences growing up, with my mom working in
       | a food safety lab, was playing with the different coloured fires
       | (and the pipettes of course).
       | 
       | I only later learned about spectrometry: roughly, the flame's
       | light is split into a rainbow with a diffraction grating and the
       | colours become a barcode for the chemicals that burn.
        
       | Metacelsus wrote:
       | "If you use alcohol as a fuel, please remember that it is much
       | more flammable than wood. Never add alcohol (or any liquid fuel)
       | to a burning fire, or it will react much [like] lighter fluid"
       | 
       | This should be at the beginning of the article, rather than the
       | end. People have suffered severe burns on multiple occasions from
       | doing the "rainbow fire experiment" and adding alcohol directly
       | to the flame.
        
         | kragen wrote:
         | i add alcohol directly to flame all the time, and even burn it
         | on my skin. there are real risks to be careful of, but i think
         | you are exaggerating them
         | 
         | alcohol is great for this kind of thing for several reasons:
         | 
         | - you can extinguish a spill with water
         | 
         | - its low boiling point protects your skin and other materials
         | from high heat, but only when they are wet with it
         | 
         | - you can mix a little water into it to enhance this surface-
         | protecting effect
         | 
         | - unlike many organic solvents, its toxicity is quite low
         | (ethanol and isopropanol, not methanol)
         | 
         | - it produces very little carbon monoxide or soot
         | 
         | that said, it can still spread fire quite far quite fast, and a
         | house fire can go from the size of a small campfire to deadly
         | flashover in under a minute, so be very careful
        
       | Log_out_ wrote:
       | May contain highly carcinogenic substances
        
         | kragen wrote:
         | may, but doesn't. christ
        
       | philipkglass wrote:
       | The colors will be purer if you use ethanol (denatured alcohol,
       | 190 proof Everclear or equivalent) as fuel. High concentration
       | isopropyl alcohol has a yellow tinge to the flame from soot
       | formation. Methanol (sold to the public in the US in convenient
       | small bottles as Heet Gas-Line Antifreeze) is also very good and
       | may be easier to obtain in some areas than pure high-proof
       | ethanol.
       | 
       | Sodium chloride, lithium chloride, copper chloride, and boric
       | acid give the most intense colors. But sodium chloride's orange-
       | yellow color is a bit boring compared to the others.
       | 
       | A few milliliters of the alcohol mixture can be ignited in a
       | shallow stainless steel dish with relative safety and there will
       | be no color interference from carbonaceous fuels yellowing the
       | flame via soot.
       | 
       | If I had to pick just one to try, I'd suggest boric acid. The
       | green flames it produces are unlike any "ordinary" fire and boric
       | acid is easy to find. Here's a short video with a good view of
       | how the flames look: https://www.youtube.com/watch?v=g1jHVk6oqjU
       | 
       | The first night that my now-wife met me in person, I showed her
       | colored fire like this in the fire pit at my apartment complex.
       | She originally meant to visit for just a few days but we've now
       | spent 21 years together. I'd say that the demonstration was a
       | success.
        
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