At 11:10 AM 12/7/2009, Bob Blick wrote: >I've always wondered why soldering gun tips like this work so well: > >http://www.cooperhandtools.com/brands/CF_Files/model_detail.cfm?upc=037103478818 > >The material appears to be made of the same alloy all the way through, >and it doesn't get thinner near the tip, so why is the very tip of it >the part that gets really hot? My experience is that the entire tip gets hot. The big, thick tubes that the tip connects into serves as a heatsink which keeps the wire temperature at that point at a touchable level. In other words, there is a temperature gradient from the end of the tip to the connections. The temperature on the wire close to the end of the tip is almost as high as the temperature on the end of the tip. Back when I was a kid, I used to make my own tips from #14 or #12 copper house wire (solid core) that I had stripped the insulation from. Worked nearly as well as the official tips, except they weren't as rigid. dwayne PS - I also used to use the soldering gun as a power supply for making magnetizing and de-magnetizing steel objects - I wound a small solenoid coil of a few turns with really thick wire. If you energize the gun with an object inside the coil and then withdraw the object slowly, the item becomes de-magnetized. If you leave the item inside the coil and quickly click, then release the gun trigger, eventually, you will turn the coil off somewhere near an AC peak. You can get a healthy amount of magnetism into a screw-driver tip that way. dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist