Heat stick build advice

[denislemieux]

I am thinking about building a heat stick (or 2) to help bring my water up to temps and save on some propane during the mash and starting boil. Was planning on loosely following instructions found here http://lovebrewingcompany.com/brewing/diy/heatstick/" onclick="window.open(this.href);return false;

Just wondering if anyone has any tips for the build of things they tried that didn't work very well and such. The number one thing I expect to hear is to use a GFCI outlet, I am all setup there.