Nichrome Wire

[lumberjack]

For those of you who have a use for nichrome wire but find it hard to come by or too expensive to purchase, this may help. You can get short pieces of the stuff out of old crock pots and hair curling irons but for long pieces (20 ft. or so); old electric blankets are loaded with the stuff. The only drawback is that the wire that comes out of the blankets is a smaller gauge wire than the stuff that comes out of crock pots and curling irons. I don't know just how much heating power that you can get from the smaller wire. I wrapped about 5 ft. of the stuff around a 25 X 50mm vial, filled it with water and hooked the wire up to a small 12 volt battery and got the water to heat to around 100 degrees Fahrenheit in about 10 minutes.

:confused: Does anybody know of any other sources? :rolleyes: Does anybody know where it can be bought fairly cheap? :confused:

[kingspaz]

Have a search on google for wire suppliers. I know there is atleast one!

As for the wire, the thinner the better. The thinner the wire the more resistance it has and thus higher heat concentration from a given voltage. I use 0.8mm nichrome. It works very, very well.

[sevin]

eBay man, it's the best place for it. I just go 150ft of 38 gauge Nichrome for about 4 dollars shipped. Nice and easy.

[Desmikes]

They sell replacement heating coils for small, table-top electric stoves or other heating appliances. These come in different sizes, and they are very cheap (I paid an equivalent of a dollar for mine). You will get a lifetime supply excellent quality nicrome wire.

[K'Luuppo]

Here they sell 5m rolls of something named "resistance wire" at electric components store. I don't know, if it's the same thing but I suppose it would work. The price of one roll is 2,70€, so it isn't really expensive.

[xxxplosive]

When I lack Nichrome Wire I end up de-tangeling a piece of steel wool and use whatever length pieces I can get out of it.

it's not fun nor easy but the stuff does work and is not a bad last resort.

the trick is to wrap it a couple of extra times aroud the thing (fuse or whatever) you are trying to light.

[Trigger Mike]

I managed to get a load of it out of an old toaster. Hairdriers are good for it aswell.

[Mr. Pseudo]

The only thing with the nichrome out of toasters, or hair dryers, is that it's very low-guage. This is not necessesarily a bad thing however. Mine requires a 70V Alkaline battery about the size of 2 decks of cards to glow. For reliable ignition however, I usually use a portable 12V car-charger.

With this system, I can set off as many as 12 simultaneous dets (perhaps more, i've never tried 13) when linked in parallel. I even tried passing the current through a 250m spool of 8-guage bell wire, and still only had a 129µs delay (up from 48µs).

I also seem to get more relable dets with the lower guage. Using .12mm hairlike nichrome, I could use a 9V battery, but ignition of a bead of Pyrodex around the wire was only 9 in 12. Using the .8mm hairdryer nichrome, I used the system above, and got 12 ignitions out of 12 also using a solid pyrodex bead formed around the wire.

When placed into coarse Pyrodex Powder, ignition was 7 in 12 for the .12 mm, and again 12 out of 12 for the .8mm.

If you are only setting off small devices, where failure would not be too tragic, by all means stick with the fine nichrome. However if you are setting off a depth-charge, or other large device, where failure would mean the loss of lots of hard work, I would suggest the more reliable, lower guages.

[Anthony]

The finer the wire, the less current needed to make it glow. Energy output in the form of heat (quantity, not just temperature) is a factor of current. So a thicker wire at the same temperature, will give out more heat, and more reliable ignition.

It would take a 70V battery to make a hairdryer coil glow if you use the whole length! If you pull a section out straight and cut off an inch, it'll burn up with a few volts.

If you have a broken hairdryer or similar appliance, then scrounge the nichrome wire from it. There's enough wire for hundreds of dets. It's a waste of money and time to buy new applicances for this though. Just buy a roll of it from any electrical supplier (even maplin, radioshack etc). It's much cheaper, your get more, it's on a convinient roll, and often you can pick the thickness and resistance that you want.

Yes, resistance wire is the same thing.

[sv_sniper]

Just got 75 feet 40AWG (0.003 inch dia) of nichrome wire for US$4.00. The seller is selling rocket stuff on eBay. Check "www.newtons3rdrocketry.com".