I love the came. What kind of hinge did you use?
2 different sizes of very small copper tubing - the smaller size just fits inside the larger size. I use 2 hinges, one on each side. Total length of each hinge is 2", one 1" piece of the larger tubing is soldered to the top, the other 1" piece is soldered to the bottom - keeping the two pieces aligned is the hardest part of this type of hinge - then a 2" length of the smaller tubing is slid into the larger tubing and soldered on ONE end only (otherwise you end up with a lock instead of a hinge), I usually solder the outer piece of each hinge to the inside piece of tubing - that keeps the top from coming off. The picture explains it a whole lot better than I can.....
