And now the complimentary warning!
I am not responsible for your stupidity. period. We are using chemicals and playing with fire. Do not eat, huff, nor burn yourself on what we make. Stay 5 feet away at the least, and wear protection. This is designed to have no hard shrapnel, and if it explodes should throw chunks no further then 5 foot.
Once again, fire hazard. think before use.
all right, now that that's out of the way...
What do we need? continue on to the next step!
Step 1: Materials
-spoon (optional, fingers are fine, this is for de-gutting)
-mini pumpkin (for a pumpkin that'll be good for a few days, plastic is fine, I used a REAL pumpkin though)
Smoke bomb materials
-KNO3 (potassium nitrate) avalible nearly everywhere as STUMP remover (see second picture) Online... ECT, Home depot's "grant's stump remover" is what I use.
-sugar (sucrose) if you don't have this...
-scale (gram scales are best unless making large batches)
-a pot (please, don't borrow mom's without her permission. Everything in the mix is water soluble and rinses out easily under hot water. Will not leave any poisonous remains, and shouldn't damage the pot a bit. If you clean the pot out by burning (my favorite) it had better be your pot, otherwise, it'll be ruined.)
-safety goggles (face shield so I don't loose eyebrows :D )
-stir rod (I like paint sticks)
-Grease (cooking/spray on fine)
-plate or smooth slab to work on
-length of fuse (5" is sufficient)
Now, I know it sounds like a ton, BUT, you should have everything but the pumpkin and stump remover at home. Fuses from fireworks are fine, but, more never hurts! May need to buy a pot too if you can't borrow one.
Step 2: De-gutting
First, take your knife and cut a pentagon around the stem. The hole SHOULD be large enough for you to stick a finger in with a little wiggle room.
Like any jack 'o lantern, pull out the seeds and guts. For the rest of the instructable, I'm working outside, this is HIGHLY recommended if you want to save your house from possible (though unlikely (if you pay attention)) damage and general mess. Clean up is as easy as sweeping the junk into the grass!
Once you are satisfied that the pumpkin is empty, DRY IT OUT!!!!! Use your paper towels and get it as dry as possible.
Step 3: Begin the Smoke Mix!
everyone seems obsessed with grinding KNO3 then melting sugar. Not only does this usually result in heavy carmelization of the sugar, impossible to mold, and a genuine fire hazard, grinding up beads to powder is slow, laborous, and just plain messy.
Besides, on an atomic scale that powder is HUGE! Let's easily turn the molecules back into individual KNO3 molecules and produce a STRONGER, better burning, more reliable, and significantly less dangerous to cook mix!
Here's what we need for our pumpkins-
So, step one of this is measure the KNO3 and pour granules into pot. JUST cover them with water and turn your stove on to med high.
Step 4: Boil...
There, that was some easy crushing wasn't it?
Now, we've super-saturated the water with KNO3, So, keep the burner on and move to the next step!
Step 5: Add Sugar
why not put it in first?
Well... the sugar will actually suck up the water and leave granules of KNO3 at the bottom. It means you have to use more water, which means a significantly longer process. KNO3 first.
We have now created a flammable mixture. Though you can't light it yet, (trust me, it ain't going to light) don your goggles and gloves, from this point on, you need to be vigilant!
it shouldn't take long for the sugar to dissolve, now you'll have both sugar and KNO3 precipitating out of the water. it's ultra-saturated at this point. stir quickly, and don't stop, this keeps the crystal sizes to microscopic levels, and also keeps them consistent. Hang in there!
PS: if your doing this inside, turn on the fan, open windows, doors... ECT, drips from the mix at this point will produce lots of smoke, setting the smoke alarm off isn't fun.
Step 6: Boil, Boil, Oh, and Boil
Also, in this stage, it will LOVE to over boil, be VERY VERY VERY careful to not let it do so. Cook on med heat.
Seriously, don't let it over boil, or you'll have smoke going everywhere, and just a general mess.
the GOOD news is that because there's water in there, the mixture can't get over 212 degrees F (100 degrees C) So, no worries, the pot will NOT spontaneously ignite. Nor will it caramelize.
Step 7: Melt
We are NEARING completion of the mix. Hang in there, and be as alert as possible to orange splotches in your pot. That means you have hot spots and are heating too fast. At this point the mixture will sustain combustion. BE CAREFUL. Seriously, wear protection.
If you're stirring properly you'll notice that the mixture suddenly doesn't want to stick to the sides anymore, but rather wants to clump together, this means we're CLOSE. one more stage to go. the water is all gone from the mix, and now the sugar is in between the boiling point of water, and it's melting point.
Pretty quickly after this, the mixture will begin to turn orange. This is the important part, if it lights now, you've got an issue on your hands. it will burn quickly and rapidly, if you see dark orange splotches, TURN THE STOVE DOWN! Once it gets to a peanut butter color, you're done! quickly scrape it to the oiled plate. (In this case a marble slab left over from a tiling job, wonderful thing it is)
Step 8: Knead and Mould!
No worries once you're slicked up though.
Below is a demo of what your mix should look like. below that is the stages of the mix, from left to right:
wet and still boiling over
not boiling over, still wet
water is gone, sugar not to melting point
slight yellow tinge, sugar is beginning to melt
sugar is melting
(big blob) sugar has fully melted and is caramelizing, remove from heat and pan quickly. Any more caramelization is detrimental.
let sit for about 15 seconds and then play hot potato with it and knead it. Can't do this with the other methods can you? if you continue to knead you'll keep the crystal formations from really growing and solidifying. this means you can get it to 150 or so degrees before it hardens!
Step 9: Fill Pumpkin
You should see something happen... (ignore with plastic pumpkin)
Water should start seeping out of the inside of the pumpkin... kinda like if you were baking it... this is BAD, before you fill the pumpkin, I'd suggest drilling a couple holes in the base to let this water out. You may want have the holes drilled from the next step done first!
The water is our enemy. basically, just let it drain and dry as much as you can with the paper towels. Plan to use the pumpkins TONIGHT. Pumpkins go bad quickly anyways, once you make the first incision, generally they have two days left before they look bad.
I used a spoonful of corn starch to suck up the water, and it seemed to help a good deal, if there's a better way, LET ME KNOW, but the cornstarch coated interior worked pretty good.
Any way you look at it, make sure to have some holes drilled in the base before you start filling the pumpkin.
Step 10: Drill Holes!
I'd recommend a about 8, 1/4th inch holes rather then lots of small holes. (see fourth picture for the CORRECT pumpkin bomb format)
Step 11: Fuse 'n Plug
Fold the fuse and shove in the newly drilled hole. it SHOULD be a tight fit in the hole. otherwise you'll have to drill another hole. (see second and third picture) You only need to have about 1/5th -1/6th of the fuse folded over, it doesn't need much, just enough to wedge it into the hole.
Why fold the fuse? Fuses send the flame in the opposite way they're burning, so, we need to redirect that flame to burn on the smoke mix. The easiest way to do this is just to turn the fuse upside down and direct it at the mix, which happens to be exactly what the fold does.
Finally, take a cork (wine bottle cork is what I used) and drill a hole for the fuse in it (1/4th again) then wrap it in paper towel until it is a really snug fit. Make it so you have to jam it in there and use a screwdriver to assist the fit. Once it's been pushed a half inch down, leave the paper towel alone and just push down the cork until the fuse is visible and easy to light. Should look like fifth picture if done properly.
Step 12: Completed! (fire at Will...)
Go out and use your newly made pumpkin bombs! Create smoke screens, confuse your archenemies, throw them at the jerks... and if you're a green goblin, just think of all the little spidermen to throw these at! (last joke = sarcasm, don't do that, no, really)
(sorry about the white balance...)