My first thought was that when I saw them. The "tinning" step of prepping the wire is left out there. If things anent shiny clean.... There was a lot of rosin in the solder we used to use. It did a nice wash job.

What is eutectic solder Larry? I take it it has similar properties to tin lead combinations.

We drifted into soldering on VTWilly's Introduction thread. Anything is possible here.