Instructions to make heated clothing

By Jason T. Sharman

From: Jason T. Sharman <>
Date: 23 Aug 1996 17:48:59 GMT

Ok, everybody. At the request of many, here is the information I have regarding making your own heated clothing. I was just too cheap to buy it and I figured it couldn't be that hard. A few days working on it at my desk at work and I had a fully heated jacket, glove liners, and bootsole, for a total cost of about $32. And I still have about 200 feet of nichrome heating wire left. Just in time for winter, here is the skinny:

Frey Scientific (I'm afraid I lost their number, but they are in Ohio I believe) sells the nichrome resistance wire I used in various gauages. Using a bunch of funny equations I found in a book, I managed to calculate the various resistances per foot of the gauges and they are as follows:

I decided I wanted a 45 watt jacket or so. Using the relationship P=E^2/R, and assuming 13.5 volts were coming out of my bike, I decided the jacket needs about 4 ohms of resistance.

I bought the 26 guage because 4 six foot strands connected in parallel gave me about 4 ohms. (Each 6 foot strand giving 15.58 ohms, 4 in parallel giving 3.9 ohms total, for about 46 watts.) I decided on 46 watts simply because that is what Widder and the others seem to rate their vests at and I figured they must know how much heat to use.

I poked the wires through a $6 Kmart work coat which was made out of light quilted satin that slid easily under my leather coat. It took some time, but I got the wires zig-zagged through and used non insulated crimp connectors. The wire shows in a few places where I poked it out to make a u bend with it and poked it back in, but the exposed wire has caused no problems. A needle and thread to sew up the small splits I made in seams for the connections and I stitched a molex connector hanging off so if it were tugged it would not come undone. And I plugged right in and it worked dandily.

A few things I learned though. Don't put wire around sholder blades because they are bonier and end up feeling hotter than everywhere else, and do concentrate more around the lower back because it feels the coldest. Also I found that a good snug jacket conducts heat to your body much better than a loose one.

For gloves I just sewed a single 6 foot strand up and down the fingers of a polypropelyne glove liner that I can slip under my gauntlets when needed. I attached molex connectors hanging off each liner that come out my gauntlet and plug to matching connectors on my handlebars by each handgrip.

For boot soles, I took felt insoles and zigzagged a 6 foot length through each one with molex connectors that stick out the top of my combat boots and plug into mates on each side of the bike.

The molex connectors yank apart very easily, so I'm not worried about being tethered to my bike in case of accident. My glove plugs pop right out every time I have to give somebody the finger without me hardly noticing.

Next, I may make a heated bag lined with nichrome wire because I hate going for pizza or MacDonalds and it being cold when I get home.

-Doctor Jason

P.S. If anybody uses this info, let me know how it went or any new discoveries that might be interesting.

Editor's note: Another source you may find useful ... see   (dead link as of 2004) contributed by Susan Diaz.

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