[ebarker]

Somewhere on the web there should be a good tutorial but I'll give you the basic rundown.

Let's start with basic defects.

a) using solder to make 'mechanical' connections
b) dirty or corroded copper
c) using the iron to melt the solder, not the work.

The answers.

a) If a connection has any sort of mechanical stress it is to be configured to handle the stress without solder. The solder just takes care of the electrical part. This is true of cable, harnesses, are larger leaded parts. Surface mounts parts have low enough mass that the soldered joint is sufficient.

b) if the materials are excessively corroded then clean the work with an abrasive material. Use solder designated for electronic work. DO NOT use solder for plumbing. plumbing solder has highly acidic cleaning fluxes and will destroy electronics. Electronic type solders has fluxes (cleaning agents) that are suited for this type work. In hobby work if you use a resin core flux solder it will smell like turpentine pine. You can leave the residue on. The new organic core fluxes wash off in water or with a damp cloth. If you leave the flux residue on it will eventually corrode and get messy.

c) what heats what ? This is where a lot of people really get messed up. The iron heats the work, the work melts the solder. Go get a perfboard with a lot of tin plated holes and a bag of cheap resistors and practice. Put the iron tip into the vee between the resistor wire and the pad. put the solder on the opposite vee and it will 'strike' and the flux will clean and the solder flow.

You don't ever want to solder butt to butt to wires. you can do it but it will be a piece of complete junk.