A new? source for fine wire.

I will unravel speaker wire for the individual strands

I'll 2nd Nathan and Don.

Round-wound strings are great for O2 hoses, or any other hose/tube of that style. .24ga is good for 72nd, .32ga for 48th, and lookin at around .52 or so for 32nd. (I use "9's" on all my guitars....9, .11, .16 for the highs, and .24, .32, .42 for the wound). Also, old guitar cables are a great source for PLENTY of fine copper wire...much easier to bend, than guitar strings!

I salvage wire from old electronics as well (electrical cords), I have a good stash of various sizes. The stuff I use most, came from the "pig tails" for the old taxiway lighting at my airport. Quite fitting, since 99% of what I build is aircraft!

What I often do for fine wire is either purchase fine electrical wire from an electric supply vendor, and also do some recycling when I throw out old electrical devices.  Transformers in electronics often have lots of fine wire- you can break the case open the case and unspool the wire (for buying the fine wire, the useful stuff is called magnet wire.

As there are fewer and fewer vendors are around for actually buying magnet wire, fortunately I have seen more and more available from craft/hobby stores like Michaels and HL.  It is in the section of these stores that caters to jewelry makers.  Sometimes this section is referred to as beading supplies.

By the way, there is a forum below called Supplies and Materials forum that frequently has threads on finding fine wire, and other useful things you may not find in your LHS.

I wish my Brother would re-string my guitar... they also work well for making oxygen hoses if you leave the winding on. 

Which string was it? is it round-wound? What is the gauge of the wire?

Thank you! never thought of that.