everyone wants to feel safe and secure. many people keep pepper spray, tasers, knives, and all sorts of other self defense items with them at all times. these are great against a human attacker or dogs and other animals, but what if the elements themselves turn against you. what will your taser do against a fire??? nothing. luckily now, with the pocket fire extinguisher, you can feel safe from the elements everywhere you go.

this instructable will teach you how to make an effective pocket sized fire extinguisher so that you can feel prepared at your next candlelight dinner.

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Step 1: How It Works

fires need oxygen to burn. if you can smother the fire, then it will go out. to do this out extinguisher uses a combination of dry powder and co2. we will use a simple co2 canister to shoot blasts of co2 at the fire, but it will also blast baking soda into the fire, which when heated produces co2. attacking the fire from two fronts

Step 2: What You Need

to build this extinguisher you will need several things:

+ a co2 canister (16g is good) THREADED
+ an old bike tube
+ some tape
+ scrap metal, or a spoon of some sort
+ some foam (for insulation)
+ a co2 canister bike adapter (see foot note)
+ baking soda (NOT BAKING POWDER)
+ a small container with fastening lid (holds baking soda)

FOOT NOTE: i had one of these nifty things lying around in one of my bike kits, but if you dont have one you can find them at most bike stores or online here: http://www.amazon.com/Genuine-Innovations-133111-Microflate/dp/B001K0LXPA/ref=sr_1_7?ie=UTF8&s=sporting-goods&qid=1247662324&sr=1-7
ignore the bad review, mine worked great for inflating tires. (and for putting out fires)

Step 3: Assembly: Step 1

now to assemble it!
first take your old bike tire and cut out the valve from it so that there is no excess rubber. (you have to leave some on to keep it well sealed)
i then took a valve stem remover (available at most autoshops) and took out the valve stem so i just had a tube with no valve this makes air get through quicker.

sorry about picture quality, i dont know what is up with the camera... it gets better as the instructable goes on...

Step 4: Assembly: Step 2

next take your scrap metal out, this is the hard part (at least to explain). you need to bend this in a way that you have an open plate to pour baking soda onto, and so that it fits snugly to the bike valve. pictures do the best job explaining this one. i made mine with side walls so that the baking soda would stay mostly in place until i shot it out with co2.
next fix the tray onto the bike valve. i used high-durability electrical tape to connect the two parts

*note you can also use a spoon instead of scrap metal for the baking soda dish and just bend if appropriate

Step 5: Assembly: Step 3

now its time to grab that fancy adapter and some foam.
how the adapter works is you screw it all the way onto the co2 canister to puncture the seal, but air doesnt start coming out until you start to unscrew it.
so lets coat this thing in some foam so that we dont have to freeze our hands when we're twisting this thing.
i used a bunch of scrap foam all taped together so it looks pretty ugly, but you can make yours look pretty if you use nice pieces of foam

once you've got it coated go ahead and insert the bike valve assembly we've been working on into it.

Step 6: Assembly: Step 4 (you're Through the Worst)

now lets grab that co2 canister.
this thing really gets cold when the air comes out of it so we have to make a real good foam coating for it.

i made my sleeve a tube that can easily be removed from the co2 canister so that when you have to replace the canister you dont have to redo all the foam work

Step 7: Assembly: Step 5 (its Almost Done!!!)

now you need a tight container to hold the baking soda when its not in your tray ready to spray.
i had a little tube container with a lid that use to store some weird medicine stuff, but anything works. just make sure its the same size or smaller than the co2 canister, other wise it might be a tight fit in your pocket.

now go ahead and fill it up with the baking soda (make sure its baking SODA not powder because baking powder will explode in flames) and attach it to the foam insulator for your co2 canister. this can be done with tape, or you can take some scrap metal and make a custom clip.

finally screw that head piece on! im suspicious that it leaks while screwed all the way on, so i just screw it a couple turns on an then screw all the way when a fire arises.

THATS IT! you're done! the final product is just slightly larger than a cell phone, easily fits in the pocket.

Step 8: Using Your Extinguisher

this fire extinguisher is meant for class B&C fires, which means it works well for grease fires, and gasoline or petroleum fires. it is not meant for combustibles like dry leaves as the co2 could blow around embers. in my tests however it was able to effectively extinguish small combustibles fires with dry leaves sticks and stuff like that. for combustibles you can always use water though so its really most useful against the class B&C fires

so how do you use it?
like this:

as soon as you hear or see that there is a tiny fire grab your extinguisher and tighten the adapter piece down all the way. then grab the baking soda canister and pour a generous heaping into the platter made form the spoon or scrap metal. point at the base of the fire and began to unscrew the canister. NOTE: twist the canister, not the adapter piece keep the adapter rig pointed at the fire.

there are some fires where baking soda is not required. if you just want to put out some candles on your birthday cake, or extinguish that guy's cigarette who is standing next to you, skip the baking soda and just let rip some co2.

check out these videos to see the extinguisher IN ACTION:
when i was putting out the candles i had low pressure with no baking soda which is why it didnt work well
the pan was filled with cooking grease and i used full pressure with the baking soda

Step 9: Further Thought

WHAT IF......
as an alternative to the co2 canister that would be a bit more diy you used an airtight container in which you could mix vinegar and baking soda to produce large amounts of co2. this is dangerous however because your container could end up exploding all over you if the pressure got too high.
i am in the process of making one of these with a pressure gauge just to make sure everything stays under control, i'll post it soon.

just in case you are wondering, if you want to make one with vinegar and baking soda you dont mix the two until your at the scene of the fire, so you would want a little storage capsule for the baking soda just like in the co2 one.

this particular reaction also produces some co2 foam which is great to use against combustibles.

please rate, comment, and vote for me in the pocket sized contest

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    17 Discussions


    6 years ago on Introduction

    So where is the cute little mini red fire ext. ? You deceived us!


    8 years ago on Introduction

    This is always an option :D http://www.coolest-gadgets.com/20060706/the-worlds-smallest-fire-extinguisher/


    9 years ago on Step 7

    thnk bary much ...... for instructable.....!!!!!


    9 years ago on Step 3

    Whats that faint reflection? I think the cam focused on that


    10 years ago on Introduction

    I think the candle is a bad example. It would blow out. But I take your word for it! Nice Job!


    10 years ago on Introduction

    Hmmm... can't wait until the baking soda/vinegar ible comes out!


    10 years ago on Introduction

    Tip for shooting close-up photos: turn on macro; it enables you to take clear close-up photos.


    Reply 10 years ago on Introduction

    thanks! i'll update this with some better photos then


    Reply 10 years ago on Introduction

    online you can get them fairly cheap. and any biking shop will carry them, also any place that sells airsoft will usually have them