Electric kettle element wire questions

[lordvader88]

I'd like to take apart a kettle for the element wire, hopefully NiCh. What does that cut like with average wire cutters, should I use old cheap ones?

I'd like to take some of it and make a little hot air soldering gun, since its what I have on hand.

How are these element wires meant to be used ? What kind of current/voltages can be used ? Are they fine with just DC ? What kind of resistance does this stuff have?

Can I just hook up 12VDC and a resistor to a 3-4" coil of it and see what kind of temperature I get for a given current?

I looked up average Kettle power ratings and they are like 1000W-2000W. Compare that to a little 40W soldering iron.

[retrolefty]

I would use old cutter if on hand. As far as the rest of your questions it's all about ohm's law, you can't proceed without knowledge and understanding of it. Your wire would represent a pure resistance. A digital multimeter would be your first tool of choice once you are ready to move on.

[floobydust]

A few things to consider, it's the heat of fire with electricity so what could go wrong 

Resistance wire in magnesium-oxide powder as the electrical insulator, just like your older stove heating elements, is what I imagine the kettle element uses for construction. The electrical insulation of the MgO, so you don't get a shock. Once you take it apart, it's a mess. It's designed for heating liquids, not air.

A hair-dryer heating element is very similar to the hot-air gun heating element, so maybe consider that, although operating temps are much lower so the materials (plastic) verses steel tube, porcelain insulator etc.
You can buy a 858D entire hot-air station for low cost, or the wand or heating element for very cheap. Less things melting for you.

[wilfred]

But the 858D+ hot air stations are so cheap on Ebay. Only AU$40 when I looked just now.

I'd consider a toaster element before the kettle one. If you just want the wire. But the heat resistant plastic is more of a problem.

[Gregg]

 Nichrome wire is readily available and less brittle than used heating elements.  Other sources if you have second hand stores nearby or attend yard sales are things like hair dryers and hot air popcorn poppers already have half the solution done for you.  Princess Auto must sell the same cheapo hot air guns that Harbor freight puts on sale often and with a cheap nozzle adapter you would only need some temperature control. 
Mica is often the insulation material in most hot air appliances to suspend the element.  The biggest problem with bare nichrome is making good connections to the copper wire.  I’ve found that making a loop in the end of the nichrome and fastening it to a ring crimp on the high temperature insulated wire with a small machine screw with washers is the most reliable.  Crimping the solid nichrome will only make a weak spot and solder has too low of a melting point.  Silver braze works on nichrome if you are good at using it.

[Cliff Matthews]

Typically I've found water heating elements to be housed in Stainless-Steel packed with baked ceramic and spiral Ni-chrome wire running down the center. To easily get at the that wire (undamaged and in one continuous piece), would probably require something like a mini pipe cutter. I tried to do this to an oven broil element once and could only pull off the outer steel tube about an inch at a time.

*Edit - Since you live in Canada, pick-up a used 1400w hair-dryer or two at a recycled-goods store and dis-assemble. I sometimes use these as ad-hoc loads which can be used immediately as 10.5, 21.0 or 42.0 ohms. There's usually two elements in a spiral wrapped around an interleaved mica-fiber form. If possible, try to reuse the TCO (cut-out fuse) in your final design for safety. Here's an example of using one for a load:

[Brumby]

Access to the wire depends on the type of element we're talking about:

This type is easy:


This type is not:


... and I haven't even dreamed of diving into those that lay hidden beneath a stainless steel bottom.

[lordvader88]

Yeah its the enclosed SS type, and I don't have pipe cutters, definitely not for steel.

I don't want to spend any money, I want to make it from saved/salvaged stuff. A guy on utube made a nice simple 12V HAG with a diesel glow plug, I might check a garage to see if they'd part with an old 1 (that still works enough)

I have a 'little' 1500W space heater, I might snip 2-3" from that and experiment with.

I have triac's on the way, they'd be useful for this I guess

[Cliff Matthews]

Yeah its the enclosed SS type, and I don't have pipe cutters, definitely not for steel.

I don't want to spend any money, I want to make it from saved/salvaged stuff. A guy on utube made a nice simple 12V HAG with a diesel glow plug, I might check a garage to see if they'd part with an old 1 (that still works enough)

I have a 'little' 1500W space heater, I might snip 2-3" from that and experiment with.

I have triac's on the way, they'd be useful for this I guess

I wonder how long that guys glow plug is going to last?

[Gregg]

I get the idea of building something with what is on hand without having to venture out into the cold Canadian winter. 
How about a couple of automotive H-4 or similar headlight bulbs; they are often replaced with the high beam intact when the low beam burns out.  (I often use them for small load banks).  They are in the 60 watt range at 14.5 volts nominal and usually free.  I haven’t tried cutting the base off one of these bulbs, but it shouldn’t be too hard with a Dremel.
The heat would have to transfer to the air stream even with the quartz envelope intact. You could use two, one for preheat and another nearer the tip for regulating the temperature.  As a side benefit it would illuminate your work.  If it works well, you could look for crowd funding.