I was moving across the border this week and I had a cheap China glass mini-rig I wanted to bring. It had a nasty stain on the male joint so I used a torch to burn it off. It went fine at first but when I got lower on the joint, I hard a pop and saw a small crack. It looked like the crack didn't go all the way through, more of a surface crack on the inside of the joint. After that I put my HE domeless on it and heated that up, to see if the crack was going to cause problems with a heated nail. I heated the nail up good and hot, then pulled it back off with a leatherman. I could see some bubbles around the joint (so I know I weakened it), but the crack was gone. Performance wise the mini-rig hasn't changed. I don't know much about boro and why I can't see the crack now, so I was hoping to get some info!