For anything 1/4" and thinner, I use .007-.009" stainless wire - you can get it at Small Parts, Inc (link below). For anything 3/8" and thicker, I use stripped down twist-ties as Swedge suggests. The potential problem with copper wire is that solvents can cause immediate oxydation and leave some coloration in the joint.
http://www.smallparts.com/products/d...ions/saw%2Ecfm
HTH,
James