I can put one together in about 45 minutes. I use a cordless drill. The instructions tell you what setting to use. I haven't used Flexwatt, but with heat cable or whatever it is, it helps to plug it in first to make it flexible. But you can't leave it plugged in, because it gets to 130 or hotter, which burns your hands. You _may_ need an adaptor to go from the three prong Flexwatt (heat cable is three prong, I don't know about FW) to your thermostat, which may or may not take grounded plugs. Herpstats didn't used to, but now you can buy a Herpstat for a grounded plug. If for some reason they don't send the instructions, I have posted them on line here for someone else.