Ok, so hopefully this hasn't been posted before, and if it has, oh well. I've made a few heat sticks following the awesome write up that The Pol wrote
One of the steps is to mix both tubes of jb weld together and "pour" it into a 1" pvc coupling. Well, when you mix the stuff it basically has the consistency of very sticky, thick peanut butter. No way that stuff is pouring anywhere. My first attempt was really messy, mostly trying to slop it in with a plastic knife. I figured there had to be a better way.
Unfortunately I didn't have the camera with me, but what I did was took a piece of parchment paper (for cooking), about 12 inches long. I squeezed out the tubes in the center and mixed it up. I then folded the paper in half, with the jb weld in the center. Then , starting with the folded over section that had the JB weld, I rolled it to the end. Then taped it shut with scotch tape. Basically you are making something like one of those pastry bags, or a tube of toothpaste. Insert the end into the coupling, and then just squeeze it out! You end up leaving a little on the paper, but considering how much I got on the outside of the coupling the last time, I think it worked really well.
Anyway, sorry no pics, but hopefully you get the idea. I read on the JB Weld site that you can cut it with a little acetone or lacquer thinner, but I dunno... I wasn't brave enough to try it.
Hope it helps.