[HN Gopher] How Silica Gel Took Over the World
       ___________________________________________________________________
        
       How Silica Gel Took Over the World
        
       Author : Hooke
       Score  : 75 points
       Date   : 2025-04-01 19:33 UTC (3 hours ago)
        
 (HTM) web link (www.scopeofwork.net)
 (TXT) w3m dump (www.scopeofwork.net)
        
       | Civitello wrote:
       | What a perfect opportunity to link to one of my favourite candies
       | https://waskstudio.com/products/sealed-fate-candy-packets
       | 
       | Balls of hard candy shaped and packaged like silica gel!
        
         | andrewSC wrote:
         | What a fun little website!
        
           | jonasdegendt wrote:
           | Every time I stumble onto it I have to resist not buying five
           | gimmicky things.
        
             | kridsdale1 wrote:
             | My favorite is the Short Sided Ruler.
             | 
             | Perfect for April 1st.
        
         | fuzzythinker wrote:
         | Got to ask why?
        
           | lovich wrote:
           | Why not?
        
           | fsckboy wrote:
           | self explanatory, it's dessi- _can_ instead of dessi- _cant_
        
           | buildsjets wrote:
           | Why ask why? Try Bud Dry.
        
         | neilv wrote:
         | Lolimsorandom/imsoedgy types have plenty of space to work in,
         | without messing with child safety.
        
         | binarymax wrote:
         | Also a perfect opportunity to link to one of my favorite comics
         | https://onegianthand.com/post/188730414621/silica-gel
        
       | Mistletoe wrote:
       | Starting to put these in my hygroscopic fertilizers was a game
       | changer. No more bricks of unusable waterlogged crap after a few
       | years. You can regenerate the beads in the microwave and you can
       | buy color-changing ones on Amazon that indicate their status.
        
       | eande wrote:
       | Another one of these fascinating super absorbent materials is SAP
       | (Superabsorbent polymer).
       | 
       | It is heavily used in diapers, tissues, water retention for
       | plants, etc. SAP can absorb liquid up to 30-60 times its own
       | volume.
       | 
       | https://en.wikipedia.org/wiki/Superabsorbent_polymer
        
         | dist-epoch wrote:
         | I think it's more expensive, and I'm not sure it can absorb
         | vapor (not liquid)
         | 
         | It's fun that it has the same refractive index as water, so if
         | you put clear ones in water they disappear. Then you ask
         | someone to put their had in a bowl with them for a surprise.
        
       | nvader wrote:
       | I didn't find this in the article, so:
       | 
       | You can "recharge" silical gel by baking in the oven at 120 C for
       | a couple of hours. If you do, be careful to remove the casing
       | before you do, unless it is heat safe.
       | 
       | I have a small collection of oven safe dessicant packs that I
       | keep on hand for emergency drying electronics.
        
         | JohnFen wrote:
         | I use a food dehydrator for this, but the principle is the
         | same.
        
           | nvader wrote:
           | When my last phone took an unsanctioned swim, my research
           | suggested that a food dehydrator is a last resort. It risks
           | forcing water vapour further into the electronics of the
           | system, rather than encouraging it to move out.
           | 
           | I did find a clever solution online that tried to induce
           | mechanical suction on your phone to force the vapour out, but
           | it was too expensive for a one off use.
           | 
           | In the end I had to resort to the food dryer anyway, after
           | the silica gel failed to work.
        
             | JohnFen wrote:
             | I've never used it for drying wet electronics. The couple
             | of times I've dunked my phone, I've just let it air-dry for
             | a couple of days and it's been good.
             | 
             | I use silca gel for storing 3D printing filament and long-
             | term clothes storage.
        
         | nemonemo wrote:
         | This sounds like a great idea, but how do you keep it from
         | being "drained" or hydrated?
        
           | mrob wrote:
           | I store mine in an plastic box with airtight lid designed for
           | food storage.
        
             | nvader wrote:
             | Precisely this! Even so, I refresh them just before using
             | them.
             | 
             | TIL about the microwaving trick. I'll have to find out more
             | about it. My concern would be the gel beads popping from
             | internal pressure.
        
           | NoahKAndrews wrote:
           | If they're not getting hydrated slowly, they're not serving
           | any purpose. The whole point is that water goes into them
           | instead of whatever you're trying to keep dry.
        
             | mrob wrote:
             | If you're keeping them on hand for drying electronics in
             | emergencies then you need to store them somewhere airtight.
        
             | filoleg wrote:
             | I think the grandparent comment meant keeping unhydrated
             | during storage (for future uses of emergency drying
             | electronics), not while it is being actively used for its
             | intended purpose.
        
           | wildzzz wrote:
           | Immediately take them out of the oven and store in the
           | smallest airtight container you have. Obviously they'll
           | absorb the humidity in the container and whatever is
           | introduced anytime you open it. Ideally, keep them in
           | containers that have an excellent seal and minimal internal
           | volume like quality ESD bags.
        
             | thfuran wrote:
             | I don't think I've ever seen an antistatic bag with a very
             | good seal, and I'm not sure it's a good idea to drop
             | something directly out of a hot oven into them either.
        
               | cma wrote:
               | Another option is a canning jar.
        
           | reverendsteveii wrote:
           | other people are suggesting the microwave rather than the
           | oven. to my mind it seems very possible that you don't keep
           | them from hydrating, you just dehydrate them on-demand.
        
           | jonah wrote:
           | In a "ziplock" bag which you have vacuumed all the air out
           | of.
        
         | jchw wrote:
         | I use dessicants for 3D printing. I've heard you can dry them
         | out safely by just microwaving them for a few seconds. I wonder
         | if that's good enough.
        
           | bayindirh wrote:
           | You can get the ones with indicators, which change color
           | according to how saturated they are.
           | 
           | You can check the color to see whether it's time to microwave
           | them, and whether they are dry once you microwaved them.
        
           | bgnn wrote:
           | I use them in my car against condensation.
           | 
           | The instructions on tge cover say 3 minutes at 700W in the
           | microwave.
        
         | Graziano_M wrote:
         | You can just microwave them too, on low power. It's much, much
         | faster and power efficient.
        
           | mrob wrote:
           | Also much harder to control. Oven drying has the advantage
           | that you can set the temperature so there's no risk of
           | overheating anything.
        
         | neilv wrote:
         | Can someone speak authoritatively on how safe/unsafe it is to
         | put the silica gel packets with cobalt chloride indicator into
         | the oven?
         | 
         | (By default, I've been assuming it's _not_ sufficiently safe.)
        
         | imglorp wrote:
         | Practical details about the types of desiccant beads and how to
         | dry them.
         | 
         | https://www.youtube.com/watch?v=6tHInlFfMcM
        
       | amiga386 wrote:
       | https://onegianthand.com/post/188730414621/silica-gel
        
       | FridayoLeary wrote:
       | Why does it have the words DON'T EAT printed on every single
       | package? you don't usually come across such warnings on other
       | products.
        
         | timerol wrote:
         | Your body likes having water inside of it, and doesn't like
         | having glass shards inside of it
        
           | lovecg wrote:
           | With millions and millions of those things around I'd guess
           | quite a few get ingested accidentally and we don't hear of
           | them causing problems. It must be pretty safe (well as safe
           | as eating a small amount of sand is).
        
             | celticninja wrote:
             | https://www.theguardian.com/notesandqueries/query/0,,-18619
             | 3...
        
           | celticninja wrote:
           | Actually they are quite safe to eat.
           | 
           | https://www.theguardian.com/notesandqueries/query/0,,-186193.
           | ..
        
             | marcosdumay wrote:
             | In small quantities. As somebody already pointed, your body
             | likes to keep its water inside it, it also doesn't like
             | when stuff carries large quantities of unmixed digestive
             | fluids from one part of your body to another.
             | 
             | They are probably quite harmful if large pieces get eaten
             | in non-small quantities. Or powder in large quantities that
             | are not previously mixed with a liquid. But I don't know of
             | anybody that tested that.
        
         | AdamH12113 wrote:
         | The packets look like the little salt packets that come with
         | fast food, and the stuff inside looks kind of like salt.
        
         | netsharc wrote:
         | Probably because they look like candy, and they're packaged
         | with food a lot?
         | 
         | Even if not packaged with food, these sachects left on the
         | table while unboxing, e.g. a pair of shoes, might entice
         | kids... And it's just easier to print "DO NOT EAT" rather than
         | have separate production lines for "for shoes" and "for food".
         | 
         | Although, from the description, it seems they're perfectly safe
         | (because they're inert) to eat...
        
         | giraffe_lady wrote:
         | I'm pretty sure it's just following the rules of the strictest
         | food packaging laws among the places they expect them to end
         | up. In some jurisdictions non-food that is directly inside a
         | package along with food needs to be labeled that way. So they
         | just do em all like that.
        
         | wildzzz wrote:
         | It's a choking hazard that is sometimes included in food
         | packaging so it's just to cover the manufacturer since they
         | don't really know what products it may end up in. Silica gel is
         | non-toxic although maybe could cause some issues if you
         | deliberately ate a huge quantity of it.
        
         | madcaptenor wrote:
         | Before I had kids I wondered this. But it's really telling you
         | to make sure your kids don't eat it.
        
         | mmmlinux wrote:
         | I realized this week for the first time exactly why. there was
         | one in my instant ramen along with its other seasoning packets.
         | If not paying attention you could easily be having your noodles
         | with added desiccant flavor.
        
       | jchw wrote:
       | > That single gram of silica gel could have an internal surface
       | area of eight hundred square meters--the size of almost two
       | basketball courts.
       | 
       | For us Americans, that's about 8600 square feet...and around a
       | seventh of a football field.
        
       | krunck wrote:
       | Lets not forget the MST3k silica gel skit in:
       | https://mst3k.fandom.com/wiki/MST3K_1103_-_The_Time_Traveler...
       | 
       | https://www.dailymotion.com/video/x8hb1jh @ 00:02:00
        
       | Animats wrote:
       | Five ads and seven "subscribe" buttons, for one short article
       | about silica gel.
       | 
       | Wikipedia has a better article.[1]
       | 
       | > You can just microwave them too, on low power... Oven drying
       | has the advantage that you can set the temperature so there's no
       | risk of overheating anything.
       | 
       | It's hard to hurt silica gel itself with kitchen level heat.
       | Melting point 1200C. The packet it comes in is more of a risk.
       | Although there are forms with other chemicals that change color
       | when humid. Also, heating wet desiccant fast enough to produce
       | steam might crack the material.
       | 
       | [1] https://en.wikipedia.org/wiki/Silica_gel
        
       | ge96 wrote:
       | The word desicant is burned into my mind from this guy talking
       | about building some AC system
        
       | benwikler wrote:
       | Can't see this headline without thinking of my favorite cartoon
       | of all time
       | https://www.reddit.com/r/me_irl/comments/sqap29/me_irl/
        
         | benwikler wrote:
         | Ah, seeing that (apparently like-minded amiga386) came here to
         | post the same thing:
         | https://onegianthand.com/post/188730414621/silica-gel
        
       | xfp wrote:
       | The ones in food are often oxygen absorbers instead of
       | dessicants. They contain iron "sand" that is, unfortunately, not
       | reusable. They're usually very flat and have a "do not microwave"
       | warning on them in addition to "do not eat".
       | 
       | (This is not to say dessicant packets aren't used in food, just
       | that not all of those packets are dessicants)
        
       | Uzmanali wrote:
       | As a kid, I imagined silica gel was a special treat. It seemed
       | like the ultimate 'DO NOT EAT' dare. I put one in my mouth,
       | waiting for superpowers or disaster.
       | 
       | Turns out, it just tasted like disappointment and regret. 10/10
       | would not recommend, but at least I lived to tell the tale!
        
       | moonlighter wrote:
       | Former W.R. Grace employee: Molecular Sieve Desiccant Beads (also
       | manufactured by W.R.Grace) are even more absorbent than regular
       | silica gel. It's found in most double-pane windows inside the
       | metal track between both panes; slowly absorbing any moisture
       | over many years to keep them from fogging/going 'blind'.
       | 
       | You can use MS to dry flowers in record time... and use it to
       | quickly heat up baby food in a pinch if needed... just put a
       | smaller container of food in a bigger pod filled with MS and pour
       | water of the MS... it's ultra-rapid absorption of water creates
       | heat as a byproduct.
        
       | jas39 wrote:
       | This is sold as crystal cat litter. Very useful to put a sock in
       | the car, the boat or the check-in luggage.
        
       ___________________________________________________________________
       (page generated 2025-04-01 23:00 UTC)