Thanks guys. I just got back from the local Law Library (my source for reference of these codes, short of buying them).
It appears after reviewing both the 2002NEC and 2005NEC, there is very little to mention about the solder issue except what's mentioned in the above comments RE the "mechnically joined" and being "insulated equivalent to..." criteria. There is no mention of whether a wire nut is or is not considered "identified for the purpose of use" as also mentioned, and I suppose a wire nut counts as insulation referencing 110.14 opening paragraph and section (B) splices.
The section seems to be more concerned with the issues of dissimilar metals such as copper and aluminum, which is understandable given the nature of potential connection failures.
I suppose twisting 18-2 standed wire counts as "mechancially joined" in this context.
Any other ideas or suggestions?
