# Why do/did Spray Cans Have a Marble? **URL:** \ **Category:** Factual Questions\ **Created:** [March 29, 2013, 12:58am UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227 "2013-03-29T00:58:40Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![flatlined](https://avatars.discourse-cdn.com/v4/letter/f/eb9ed0/32.png) [@flatlined](https://boards.straightdope.com/u/flatlined)\ **Post date:** [March 30, 2013, 3:49am UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/21 "2013-03-30T03:49:08Z")
> [@dstarfire](#): > > I’ve always wondered why aerosol cans needed warnings about “do not puncture or incinerate”. Now I know why. +1 However, back in my misspent youth, there was that time that I tossed a firecracker into a broken sewer line to see if methane was as explosive as I’d heard. It was. That’s when I learned that blowing shit up often means that shit rains down on you. ---
**Author:** ![dougie\_monty](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@dougie\_monty](https://boards.straightdope.com/u/dougie_monty)\ **Post date:** [March 30, 2013, 5:51am UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/22 "2013-03-30T05:51:31Z")
George Daniels, in his book _Make Your Own Monstrosities with Tooth and Nail,_ gives simple instructions for painting your living room. Light the fire in the fireplace, and throw several cansful of your selected color into the fire, and the resulting explosion will coat the room and everything in it with paint. All you need to finish the job is an old mop. There are no brushes to clean, no rollers to wash, no glass in the windows. 😃 ---
**Author:** ![garygnu](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garygnu/32/2924_2.png) [@garygnu](https://boards.straightdope.com/u/garygnu)\ **Post date:** [March 30, 2013, 6:56am UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/23 "2013-03-30T06:56:30Z")
> [@JLRogers](#): > > This is a common misconception. In fact the “marble” or “pea” is the seed of the paint tree. Although these days they grow almost exclusively in ordered rows on factory farms there was a time when the paint tree was a common sight in North America. That which we call “paint” is actually the mesocarp, or fleshy portion, of the paint fruit, and due to the chemistry of the fruit’s development it is naturally under pressure. Humans have long drained the fruits for their paint, but it was not until 1949 that Bonnie Seymour developed the technology to lop off the stem and attach a valve to the fruit without losing pressure. Thus “spray paint” was born. > > Unfortunately, due to poor husbandry our current cultivated population of paint trees suffers from an artificially-limited genetic base, and many paint shades that were once common have become rare or extinct. Luckily the paint tree is quite prone to mutation, and unculled populations tend to manifest novel colors within three generations. In order to return this majestic species one would do well to encourage its wild proliferation. As the paint tree easily finds root with even minimal nutrients and light this is best accomplished by discarding empty “spray paint” in fields, by the side of the road, in public gardens, or anywhere else they might germinate. I am posting this on the employee wall at the art supply store where I work. ---
**Author:** ![dougie\_monty](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@dougie\_monty](https://boards.straightdope.com/u/dougie_monty)\ **Post date:** [March 30, 2013, 7:23am UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/24 "2013-03-30T07:23:41Z")
Don’t post George Daniels’ painting tip–they may try it on _you!_ 😃 ---
**Author:** ![Michael63129](https://avatars.discourse-cdn.com/v4/letter/m/3da27b/32.png) [@Michael63129](https://boards.straightdope.com/u/Michael63129)\ **Post date:** [March 30, 2013, 5:12pm UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/25 "2013-03-30T17:12:34Z")
> [@dougie\_monty](#): > > George Daniels, in his book _Make Your Own Monstrosities with Tooth and Nail,_ gives simple instructions for painting your living room. Light the fire in the fireplace, and throw several cansful of your selected color into the fire, and the resulting explosion will coat the room and everything in it with paint. All you need to finish the job is an old mop. There are no brushes to clean, no rollers to wash, no glass in the windows. 😃 Of course, there wouldn’t be any house left to mop up (actual warning on a can of spray paint: “Danger: Extremely Flammable!”). ---
**Author:** ![dougie\_monty](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@dougie\_monty](https://boards.straightdope.com/u/dougie_monty)\ **Post date:** [March 30, 2013, 5:54pm UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/26 "2013-03-30T17:54:21Z")
Well, that’s _modern_ paint. The paint manufactured circa 1960 might not have been thus formulated. ---
**Author:** ![yoyodyne](https://avatars.discourse-cdn.com/v4/letter/y/a9a28c/32.png) [@yoyodyne](https://boards.straightdope.com/u/yoyodyne)\ **Post date:** [March 31, 2013, 3:15pm UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/27 "2013-03-31T15:15:36Z")
> [@Jinx](#): > > That’s what I was told, but how does the marble know??? The marble is trapped in the unstirred gunk at the bottom of the can until the contents are sufficiently mixed; then it is free to contact the sides of the can. ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [April 1, 2013, 9:40am UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/28 "2013-04-01T09:40:32Z")
> [@dstarfire](#): > > I’ve always wondered why aerosol cans needed warnings about “do not puncture or incinerate”. Now I know why. That’s odd - are you required to puncture cans before disposal in some countries? Because I see Japanese gadgets for puncturing cans (at least that’s what I think they’re for, I can’t read Japanese). ---
**Author:** ![JBDivmstr](https://avatars.discourse-cdn.com/v4/letter/j/b4bc9f/32.png) [@JBDivmstr](https://boards.straightdope.com/u/JBDivmstr)\ **Post date:** [April 1, 2013, 10:10am UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/29 "2013-04-01T10:10:24Z")
> [@AaronX](#): > > That’s odd - are you required to puncture cans before disposal in some countries? Because I see Japanese gadgets for puncturing cans (at least that’s what I think they’re for, I can’t read Japanese). Cite (pictures) please. ---
**Author:** ![AaronX](https://avatars.discourse-cdn.com/v4/letter/a/7bcc69/32.png) [@AaronX](https://boards.straightdope.com/u/AaronX)\ **Post date:** [April 1, 2013, 11:29am UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/30 "2013-04-01T11:29:35Z")
> [@JBDivmstr](#): > > Cite (pictures) please. Hmm can’t find the exact item I’m looking for, but it was something similar to this: [https://lh6.googleusercontent.com/-nONV\_9\_ezHI/UVlu8-AdJII/AAAAAAABOXY/b6\_Zg20hpP0/s800/KIC\_173\_\_54953.1362440104.1280.1280.JPG](https://lh6.googleusercontent.com/-nONV_9_ezHI/UVlu8-AdJII/AAAAAAABOXY/b6_Zg20hpP0/s800/KIC_173__54953.1362440104.1280.1280.JPG) i.e. very simple/cheap construction, doesn’t look heavy duty. The one I saw was like a pair of curved tongs, to fit the can. In one of the curves was a rubber stopper. Come to think of it, I don’t think a rubber stopper would have been able to puncture an aerosol can. ---
**Author:** ![JBDivmstr](https://avatars.discourse-cdn.com/v4/letter/j/b4bc9f/32.png) [@JBDivmstr](https://boards.straightdope.com/u/JBDivmstr)\ **Post date:** [April 1, 2013, 12:52pm UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/31 "2013-04-01T12:52:42Z")
> [@AaronX](#): > > Hmm can’t find the exact item I’m looking for, but it was something similar to this: [https://lh6.googleusercontent.com/-nONV\_9\_ezHI/UVlu8-AdJII/AAAAAAABOXY/b6\_Zg20hpP0/s800/KIC\_173\_\_54953.1362440104.1280.1280.JPG](https://lh6.googleusercontent.com/-nONV_9_ezHI/UVlu8-AdJII/AAAAAAABOXY/b6_Zg20hpP0/s800/KIC_173__54953.1362440104.1280.1280.JPG) i.e. very simple/cheap construction, doesn’t look heavy duty. > > The one I saw was like a pair of curved tongs, to fit the can. In one of the curves was a rubber stopper. Come to think of it, I don’t think a rubber stopper would have been able to puncture an aerosol can. Wow! I have to agree, that is exactly what it looks like it’s for. I guess it makes sense for a country that already has limited space. I, for one, squeeze the air out of plastic drink bottles, and then screw the cap back on while I have it crushed. They take up less room in the garbage can, that way. 😉 ---
**Author:** ![maggenpye](https://avatars.discourse-cdn.com/v4/letter/m/ecc23a/32.png) [@maggenpye](https://boards.straightdope.com/u/maggenpye)\ **Post date:** [April 1, 2013, 7:34pm UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/32 "2013-04-01T19:34:18Z")
> [@dougie\_monty](#): > > George Daniels, in his book _Make Your Own Monstrosities with Tooth and Nail,_ gives simple instructions for painting your living room. Light the fire in the fireplace, and throw several cansful of your selected color into the fire, and the resulting explosion will coat the room and everything in it with paint. All you need to finish the job is an old mop. There are no brushes to clean, no rollers to wash, no glass in the windows. 😃 [![](https://i.ytimg.com/vi/T9MAmWnOznI/hqdefault.jpg "Painting His House | Funny Clip | Mr Bean Official") ](https://www.youtube.com/watch?v=T9MAmWnOznI) It’s not an aerosol, but the same idea. \*\* JLRogers\*\*; very nicely done. _claps_. ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [April 1, 2013, 7:38pm UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/33 "2013-04-01T19:38:02Z")
> [@JBDivmstr](#): > > I, for one, squeeze the air out of plastic drink bottles, and then screw the cap back on while I have it crushed. They take up less room in the garbage can, that way. 😉 If you screw it on, then crush it, you can simulate a spray can 🙂 ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [April 1, 2013, 9:30pm UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/34 "2013-04-01T21:30:12Z")
I started out thanking my lucky stars that my kids never added this to their mischief repertoire. > [@GaryM](#): > > I can say with some authority that when the can stops spraying it doesn’t mean there’s no pressure. Used a can opener to remove the marble. My folks weren’t happy with the red painting the wall. :eek: Then I read this. > [@flatlined](#): > > +1 > > However, back in my misspent youth, there was that time that I tossed a firecracker into a broken sewer line to see if methane was as explosive as I’d heard. It was. That’s when I learned that blowing shit up often means that shit rains down on you. Now I’m a little dissappointed. I would have loved to see that. I console myself with the thought that they would have probably gone on to other firecracker related stunts that I wouldn’t have found so amusing. ---
**Author:** ![flatlined](https://avatars.discourse-cdn.com/v4/letter/f/eb9ed0/32.png) [@flatlined](https://boards.straightdope.com/u/flatlined)\ **Post date:** [April 2, 2013, 4:23am UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/35 "2013-04-02T04:23:11Z")
> [@Yllaria](#): > > I started out thanking my lucky stars that my kids never added this to their mischief repertoire. > > Then I read this. > > Now I’m a little dissappointed. I would have loved to see that. I console myself with the thought that they would have probably gone on to other firecracker related stunts that I wouldn’t have found so amusing. Do remember that your kids are the ones who will be picking out your nursing home! Honestly, it only took one shit covered firecracker moment to make me never blow shit up again. Picture if you can, a 14 year old kid who spends a lot of time in the library. All of the knowledge is just words, nothing really processes, but reading is good. Imagine her seeing a broken place in a sewer pipe and smelling it as she walks by. See the wheels in her head start to turn as she thinks that she read that sewer gas blows up and remembers the firecrackers hidden in her locker. Now imagine the interested look on her face as she leans over to drop the firecracker into the break. Notice that she is leaning over the hole to watch what happens. And the sudden fear as a brown geyser happens. Scrambling panicked run, shit falling all over the place. I was an idiot kid, but I was smart enough to learn from that experience. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [April 2, 2013, 6:28am UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/36 "2013-04-02T06:28:05Z")
> [@flatlined](#): > > +1 > > However, back in my misspent youth, there was that time that I tossed a firecracker into a broken sewer line to see if methane was as explosive as I’d heard. It was. That’s when I learned that blowing shit up often means that shit rains down on you. Pure comedy. Would love to see a recording. ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [April 2, 2013, 6:30am UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/37 "2013-04-02T06:30:30Z")
But yet you keep a paint gun by your door. ---
**Author:** ![JBDivmstr](https://avatars.discourse-cdn.com/v4/letter/j/b4bc9f/32.png) [@JBDivmstr](https://boards.straightdope.com/u/JBDivmstr)\ **Post date:** [April 2, 2013, 11:21am UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/38 "2013-04-02T11:21:58Z")
> [@flatlined](#): > > Do remember that your kids are the ones who will be picking out your nursing home! > > **Honestly, it only took one shit covered firecracker moment to make me never blow shit up again.** > > Picture if you can, a 14 year old kid who spends a lot of time in the library. All of the knowledge is just words, nothing really processes, but reading is good. > > Imagine her seeing a broken place in a sewer pipe and smelling it as she walks by. See the wheels in her head start to turn as she thinks that she read that sewer gas blows up and remembers the firecrackers hidden in her locker. > > Now imagine the interested look on her face as she leans over to drop the firecracker into the break. Notice that she is leaning over the hole to watch what happens. > > And the sudden fear as a brown geyser happens. > > Scrambling panicked run, shit falling all over the place. I was an idiot kid, but I was smart enough to learn from that experience. (bolding mine) “shit covered firecracker moment” A+ Bwa-ha-ha-cough-choke-spit-sputter-gasp-wheeze-ha-ha-ha!!! 😃 ---
**Author:** ![Myron\_Van\_Horowitzski](https://avatars.discourse-cdn.com/v4/letter/m/9de053/32.png) [@Myron\_Van\_Horowitzski](https://boards.straightdope.com/u/Myron_Van_Horowitzski)\ **Post date:** [April 3, 2013, 5:11pm UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/39 "2013-04-03T17:11:14Z")
The marble thingy is called a “glacket.” ---
**Author:** ![Jake](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@Jake](https://boards.straightdope.com/u/Jake)\ **Post date:** [April 3, 2013, 6:38pm UTC](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227/40 "2013-04-03T18:38:05Z")
> [@JLRogers](#): > > This is a common misconception. In fact the “marble” or “pea” is the seed of the paint tree. Although these days they grow almost exclusively in ordered rows on factory farms there was a time when the paint tree was a common sight in North America. That which we call “paint” is actually the mesocarp, or fleshy portion, of the paint fruit, and due to the chemistry of the fruit’s development it is naturally under pressure. Humans have long drained the fruits for their paint, but it was not until 1949 that Bonnie Seymour developed the technology to lop off the stem and attach a valve to the fruit without losing pressure. Thus “spray paint” was born. > > Unfortunately, due to poor husbandry our current cultivated population of paint trees suffers from an artificially-limited genetic base, and many paint shades that were once common have become rare or extinct. Luckily the paint tree is quite prone to mutation, and unculled populations tend to manifest novel colors within three generations. In order to return this majestic species one would do well to encourage its wild proliferation. As the paint tree easily finds root with even minimal nutrients and light this is best accomplished by discarding empty “spray paint” in fields, by the side of the road, in public gardens, or anywhere else they might germinate. _ **BEAUTIFUL!! 😛** _ [Previous page](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227.md?page=1) [Next page](https://boards.straightdope.com/t/why-do-did-spray-cans-have-a-marble/654227.md?page=3)