Firstly, to deal with the obvious: the term sparkler bomb is a bit of a misnomer, the burst isn't contained - there's no explosion, just a large woosh. There are, of course, ways to contain them and make a bang, but doing so is (frankly) twattish and far, far less fun (even before it goes wrong and puts you in A&E).
Secondly: this post is offered as a bit of fun, not as an instructable - if you're silly enough to try and recreate (or better) my mischief, then the consequences lie with you and you alone.
Anyway, moving on...
One of my earlier memories of being on the internet, was delight at finding pages talking about creating sparkler bombs. Pages much like this post (in fact, I'm all but certain that was one of them, I remember the humour and definitely remember the imagery).
Much like any obsession on the earlier web, I only had photos to go on (Youtube wouldn't be created, let alone mainstream, for years - even where videos were recorded, they were shared as framegrabs).
The photos, though, showed some fairly spectacular results:
That blue line is an artefact of the CCD in the camera the image was captured on (i.e. it's not really there), but it does nothing but add to the effect.
At the time, I couldn't possibly have built a sparkler bomb myself - being too young to buy the things was a surmountable obstacle, but not having the funds to buy them in the first place was not. And so, some things that should not have been forgotten were lost - at least for a time.
Actually, I have periodically thought about them - usually when handed a sparkler - but the thought's slipped from my mind well before being able to act on it.
Recently though, I had need for a couple of small sparklers (think of things you put on a cake), and had the rest of the pack left over. Being mini sparklers it was never going to be anything near as spectacular as the image above, but nowadays we do have an availability of cheap video cameras to watch things in slow-mo so I figured it'd still be interesting to try.
The initial attempt was extremely small, I wanted to check a few assumptions, as well as (hopefully) not oversaturate the camera's sensor (so that the way it burns is visible). So I wired up a small bundle of 9 sparklers
The result, as you might expect, is simply a very quick burn
In the slow-mo, though, we can see a few things about the way in which it burns - not least that it keeps that sparkler property of pushing outwards, so you get a band of fire working it's way down the sparkler bundle whilst throwing what starts to look like tracer fire out.
It was time to build a bigger version. Still not massive - I'm a) not drunk b) a parent so have to be at least semi-responsible c) not too sure anyone nearby would thank me for a huge one. On Dan's Sparkler Bomb Sizing Guide this would be classed as "Domestic".
So, the next one was 6 bundles of 10 with a sparkler jammed in the middle as a fuse (chosen, in no small part, because a manufacturing defect on it reminded me of "the candle with the handle" from Allo Allo
Small a bundle as this may seem, the flame still makes it 3x the height of the sparkler material
It also utterly destroys the tin foil I'd put behind it as a rudimentary blast shield (the intention was only ever to stop sparks flying that way) as well as obliterating the majority of greenery that had been in front of it.
Because the camera auto white-balances, it's easy to miss just who bright it got - look at how comparatively dark the background gets - on a scale of 1-10, it burned fucking bright.
The result is a charred, fused mess of wire, and a fairly large hole in the substrate that had been holding it upright
Whilst I could build much bigger and more spectacular
- Sparklers are fucking expensive nowadays
- Unlike the early pioneers I'm not in the middle of Australia, there isn't anywhere round here you could safely and legally set a bigger one of
- I'm not drunk
And, of course, nowadays we have Youtube and news websites, so can clearly see that the net result of humanity being able to build large sparkler bombs, is a bunch of teenagers accidentally blowing bits off themselves (as I said before, containing it to make an explosion is a really, really bad choice to make).
It was good fun to play about at a safer scale though, and finding that some of the sparkler bomb pages I used to read are still available on the net was a nice surprise.
It also makes for quite a nice GIF