I built a heatstick yesterday, but noticed that there's an thick exposed piece of rubber at the connection end. Does that need to be sealed with JB Weld, or will that be OK in the boil?
It's the black part right under the thread on the heating element http://i.imgur.com/0juEG.jpg
You can see some black stuff exposed, and that's the rubber.
If that's the seal that came with the element, you should ok to run it. If your concerned, submerge it in water to see if it leaks.(unplugged of course)
There is a silicone that is foodgrade if you want to make sure....
I am not worried about the leaks, but about something leeching into my beer.
I looked through a bunch of pictures of heat sticks, and I can't tell what others have done with the rubber seal.
Get yourself a different "nut" one that goes to 1 1/4" not 1 1/2". That will cover the rubber seal and make for a much nicer heatstick. You can pick one up at Lowe's, I haven't seen them anywhere else. In addition I smeared mine with food-grade aquarium silicone before screwing everything together to ensure it all was watertight.
Give it a shot and see how it works, stick it in your pot and boil some water for an hour. Let it cool first, then taste it. If it tastes nasty then start over, if it trips the GFCI then start over. If everything works out well, then you're golden.
Think about where that gasket normally goes, inside of a hot water tank. I'd have to imagine that nothing dangerous is going to be in there, so the taste method worked well enough to satisfy me. I boiled water in a saucepan with the gaskets in it for an hour then tasted the water and didn't get any off flavors, so I used them. Now the JB Weld, I don't know anything about. Mine didn't have any JB Weld on the outside, only food grade silicone. If you're really worried about the gasket you can pick up some silicone o-rings that should work for you.
I am being paranoid, but better safe than sorry. I may just go and pick a different kind of sealant and coat the outside of the nut. I did so much reading, but missed the huge 50+ page thread which talked about ways to improve the design from http://www.cedarcreeknetworks.com/heatstick.htm