This question may be slightly off topic, but I'm hoping I'll find the expertise I need on this site. I'm making a bird feeder out of a wine bottle, and wrapping 8-gauge copper wire around the bottle. The problem is, I can't get the wire smooth because it's so thick. Does anyone know how I can manipulate the wire so it's smooth around the bottle?
Wire that is 8 AWG is just a smidgen over 1/8" in diameter. Copper wire is also a soft metal that actually bends fairly easily.
The trick to bending wire into a shape is to bend it around an object using the object as a mandrel. If your project is similar to producing something like the following then I think you can bend the wire simply using the bottle as the mandrel. For the tight turns at the neck of the bottle I would start by using a longer than needed length of wire at the broad part of the bottle and wrap down through the tighter and tighter turns at the neck. If you have an extra length to hold onto as you get into the tight turns it should be relatively easy to just form it around. After the bends are complete then cut off the excess foot or so of wire. In the example shown the maker actually formed a decorative ending on the wire.
Get a piece of pvc pipe about the same diameter the wine bottle. A little smaller is better. PVC has the advantage over glass of being non-breakable. Calculate how much wire you need (# of turns times diameter, plus a few extra feet). Drill a hole at the end of the pipe that your wire will fit through. Insert the wire and give the inserted part a good bend, so it's stuck in the pipe. Clamp the pipe in a vice or similar and start wrapping. Start each turn by hand, then pull tight from the end of the wire with a vice-grips or similar. Pulling will get the loops tight arond the pipe. Pulling from the end will keep all wire damage localized where you can cut it off. When you've got a long enough helix, just cut off the excess wire, and work your spring onto your wine bottle.