Desktop Hand Warmers I use these because I work on my computer and I often need to warm up my hands. I tend to fumble the keys when my hands are cold. The Tea Cup Hand Warmer Get a teacup or tea mug with a lid, fill it with hot tap water, then put the lid on it. I use the Glass Nordic Mug it stays hot surprisingly long. The Flower Pot Hand Warmer On the interwebs, there is one popular design that traps the heat from a tea light and radiates it outward to better heat a room. I don t think this is a practical use for the device but I found the design can be altered a bit to make a good hand warmer. People are always bringing up thermal dynamics, trying to point out how useless such devices are, probably because the people presenting their designs on the web do not really make it obvious what the devices are actually for. So I should make it clear, they are not a means of producing more heat than a lone tea light (this would be impossible), they are a means of taking the heat of a tea light and radiating it horizontally. In my case, I am focusing the heat as much as possible to the outer wall of the flower pot so that the heat can be easily absorbed through one s hands. The design derived from: http://tacticalintelligence.net/blog/how-to-make-a-candle-heater.htm My design, just like the one in the link, is a small flower pot turned upside down over a tea light. At first, I tried the smallest pot I could find (which was not much bigger than a coffee mug). I could not use a pot this small because the surface of the pot would heat up too much no matter how I configured it. Then I tried a larger pot and found it to be much more manageable, and more comfortable as well.
I simply bound the saucer to the main part of the pot with three threaded rods and set a tea light on top of the saucer in the middle. The saucer is bound to the pot so that the device can be moved with the tea light easily, and so the tea light can be centered in the device easily. A gap is left between the saucer and the main part of the pot so a tea light can be added or removed. The flame disperses heat to the inside of the pot, which is eventually felt on the outside of the pot. When the hole at the top is not covered up, the pot does not reach a desirable temperature. I tried to cover the hole up with a coin, but this only helped heat the top half of the pot. I later placed a large bolt down the center to disperse heat to the bottom of the pot. You will need 1. 1x unpolished flower pot with a drainage hole and that comes with a saucer. The pot in this case, must be 5 tall, 3.5 in diameter at the base, and approx. 6 in diameter at the top. 2. 1x tea light. 3. 3x 7.5, ¼, threaded metal rods. 4. 12x ¼ split-lock washers. Preferably ones with a larger spring and less resistance, this will reduce the chances of the pot cracking. I took flat washers and bent them but the resistance was too much and I cracked my pot. 5. 12x ¼ hex nuts. For aesthetics, 3 of them should be acorn. 6. Diamond head drill bits or carbide masonry bits. 7. A decent drill. 8. 1x bolt that has a diameter just small enough to fit into the drainage hole, but a head big enough to keep it from falling all the way through. I am have used a 4 bolt but will experiment with longer bolts later (to see if I can heat up the bottom of the pot more). This is the radiator bolt. 9. 7x washers for the radiator bolt. 10. 7x nuts for the radiator bolt. 2 should be split-lock.
11. 4x thin adhesive pads. Something that can fold over the saucer rim. Creating the Hand Warmer 1. Place down a small piece of cardboard, place a tea light over it, then put 3 nuts around it in triangle formation. There should be a 1 to 2 mm gap between the teacup and the nuts. 2. Mark the drill points on the cardboard with a marker or by depressing the drill bit, you plan on using, into the cardboard. This piece of cardboard will be used as a reference for drilling holes into the base of the pot and the saucer. 3. Place a pot upside down on a table (the base of the pot will still be the end with the drainage hole). Drill 3 holes centered on the drainage hole using the cardboard reference. (See this article for drilling through unglazed clay flower pots.) 4. Drill 3 holes in the same manner through the saucer.
5. Bind the flower pot to the saucer with the 3 metal rods. If you have chosen to use capped nuts, the rods would have to be attached to the base first, otherwise, start by attaching the rods to the saucer. Use 2x nuts and 2x washers for each hole. The gap between the pot and the saucer should be the height of the tea lights you will be using plus 1-2 mm. 6. Slip the large bolt into the drainage hole and use the washer/nut configuration below. Note, I am using a smaller nut at the top in an attempt to radiate less heat around the top of the device. 7. Make 3 marks around the pot where the tea light would be slipped in to help find the right angle to insert the candle at.
8. Fold the 4 adhesive pads over the rim of the saucer evenly spaced around the circumference (where the saucer touches the surface it is placed on). This will keep the saucer from scraping your desks and tables.
Creating the Tea Light Handler Take an expansion slot insert and make one 90 degree bend and another 180 degree bend near the end so that it can mount a tea light.
The handler can then be used to easily add and remove the tea light.
Creating the Glove The device might get too hot to be used comfortably. This happens after about 4 minutes with my particular setup. When this happens, a glove can be slipped over the device to make it more comfortable again. Simply cut the ankle part off of a sock and slip it over the top of the device. Note: I had the toe cut off on this build but it s better to leave it on. Also notice how the handling rim is not covered by the glove. This is because that build did not have a radiator at the time and the rim never got hot. Optionally, a hole can be cut in the middle of the toe-end of the sock so that it can be elegantly attached to the top of the radiator bolt. Then the sock would be kept on the device and used much like a curtain. Pin the sock between the washer and the bolt head in opposed to the pot and the washer. If the sock is in under the washer, it will be subject to some hot air coming up between the bolt and the drainage hole; this hot air will burn the sock and cause nasty fumes. Cations 1. Devices like this are known to superheat the wax in tea lights and cause the entire tea light to catch on fire. They are not much safer than an open-flame candle so use basic candle safety with the device.
2. When the device is in use, avoid touching the metal elements on the top of the device because they get hot rather quickly (the glove will help with this). 3. While creating the device, the worst mistake to make is overtightening the nuts. This can crack the pot immediately or cause the pot to crack later on. My pot started with a small crack, and is all kinds of cracked up now. 4. Be careful when removing a recently used tea light from the device, the tea light s wax may be completely liquefied so removing the tea light too aggressively might mess up the wick. 5. Make sure the center bolt covers up the drainage hole completely when using the glove, because hot air coming through the hole can burn through the glove. 6. Polished nuts and bolts may give off unwanted vapors/fumes/flux when heated by the device. Potential Improvements 1. The top of the device still gets way too hot way too fast. I d like to focus the heat onto the areas that are actually touched by the hand. I can block the convectional heat with a disc. I d need to insert a disc right under the pot base that acts as a heat barrier and will not give off fumes when heated up. Shoving aluminum foil up there might help a bit. A bigger radiator and radiators on the rods may or may not reduce the amount of heat conducted to the top of the device. 2. A sequence of metal rings could be added onto the tea light handler, or perhaps mounted to the saucer, so that the tea light can be lit easily without removing the tea light from the device.