| But I started getting ready while poking around in
a store after Christmas and noticed these little strings on sale for half
price: $.50 for a string of 50. I bought a couple of strings for camping. Teresa's research requires that we go camping quite a lot. We have to go into the boonies and study some aspects of the wildlife therein. It makes for a long day, and we don't quit until it is too dark to take pictures. Sometimes not even then. |
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So by the time we reach camp, it is pretty well night.
We hang these strings of little lights over the tree branches and plug them into a power inverter running off the spare truck battery. They provide a very pretty light for dinner, dancing, and stimulating conversation way out in the woods. These are much more pleasant than the light-blaster Coleman lantern, which I treasure but don't like to look at. And they don't attract insects either. Entomologically correct. |
| When winding the string back up, I noticed something...
They are wired in SERIES! There is one wire running from light to light to light, and another running from the far end back to the plug. Series! So let me count: 110volts divided by 50 lights... well, that is a little over 2 volts per bulb, right? I did that in my head! Aren't you proud? But that means these are long strings of penlight bulbs for a penny apiece! |
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| I tested one with my Co-Pilot altimeter and found
that it does indeed light it up. So well, in fact, that if you let it
stay on for more than a few seconds, it burns the bulb out. That filament isn't very big, but it shines brilliant white. So its temperature would be what, 5000 degrees? Seems like that could be used to ignite something, if placed in close proximity to some readily ignitable substance. Voila! The JimmyFire! Here is the stuff I'll be using. Pistachio nuts are a recommended option. |
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Yeah, I could clean them with fine sandpaper just
about as easily. Or I could leave them dirty and count on the flux to do the job. But I like to solder clean wire. I like to see the redheads smiling at me. It has a good feeling about it. Feels like a reliable connection. I have split a foot-long piece of shooting wire an inch or two, and stripped a little insulation off each end. These wires are clean, but if they had not been, there is that little vial of acid just waiting... |
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The soldering iron has been heating quietly on the
side. Sometimes I think it should have a whistle like my tea kettle.
There is already a drop of solder on the tip, so all I have to do is touch it to the cleaned, fluxed copper and the solder flows like magic. Aaah! This means that I don't have to juggle three things with two hands. By doing a bit of prep work, I have enough hands to go around. |
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Here I am using a small torch to heat the tip of
the bulb. I got distracted taking the picture and overheated this bulb, creating a problem. It only takes a couple of seconds - when the orange flame appears, it is hot! The tip of the bulb is dipped in shallow water, causing it to fracture. As soon as it hisses, take it out. It's done! |
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Here are our three bulbs. They have all fallen
for the latest craze. Click on the picture to bring up a larger version,
and notice the one in the middle. This is the one I overheated - see
the melted spot just before the tip? That's a problem, because when
it hits the water, it doesn't just craze, it fractures and draws up water.
See the meniscus of water just to the left of the melt-hole? Note
the water at the internal blob-of-glass insulator? All is not lost. Just break the wet bulb open and let it dry. Or if you are in a hurry, heat it until the water boils off. The other two don't have any water, despite having lost their tips. They were properly heated, and barely dipped. But do check them all for water intrusion because that little bit of water could render the pyrogen non-flammable. |
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Guess you could see this coming. I take the
rusty pliers and pinch off the crazed glass. It's very easy, and the risk of getting cut is low. But if you want to wear gloves and goggles, I would certainly not make fun of you. Not to your face anyway. Here are our three little bulbs again. The middle one still has some water in it, but it tested OK, as we shall see. The bulbs are ready to seal up with a little pyrogen. |
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Now we can dribble in the pyrogen. Here I
am adding 0.2 grams of Red Dot, which I find to be excellent for this purpose.
Black powder also works, and I'm sure there are other things. This is NOT the full ejection charge, it is just enough to set fire to the ejection charge, plus a little more just to be sure... It's a bit of a chore to get the powder past the sticky tape, but be sure some goes in the little glass thingy. I use the point of the loading wing to pack in gently in. Gently, so that the filament is not broken - at this point you can't see it. |
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Test
1: Red Dot You could hardly see
that one fire. Smokeless powder is also pretty much flameless powder.
But you will note that it had enough force to bend the wire and jostle the little plastic vise.
These have plenty of hot air to ignite an ejection charge - I have used them
on about two dozen flights so far (as of 12/05) and none of them have failed to ignite the
charge. Test 2: Black Powder At least this one has a bit of smoke and a bad smell. Red Dot smells like baby powder. But black powder offers good bit of visible flame to convince the public that this is indeed an ignition source. Test 3: Black Powder with Ti flakes Finally, some drama. It is hard to imagine a pyrotechnic compound resisting ignition with those little balls-o-fire dancing around. Sometimes I use magnesium flakes, which are similar to Ti in their effect. If Mg flakes are hard to obtain, one can get an "emergency fire starter" from the camping section of Wal-Mart - it's a bar of magnesium with a sparky striker on one side. Just use a knife to scrape off some flakes. But the metal is superfluous. Plain BP or Red Dot is perfectly adequate for this purpose. Metal would be more appropriate for motor ignition, and that is not what these ignitors are for. See warning above. |