Quoted from vid1900:
We do ALL of our soldering from the back side (non component side) of the PC board.
I'm not going to turn this into a soldering tutorial, but I'll run you through the routine.
Turn your iron up hotter than normal because the end pins often have to be soldered into the large ground plane traces, and these act as big heat sinks. I run at 480° F, but if you are a beginner, use a lower temp until you know what you are doing.
Do all the thick ground plane and power plane traces first, with your hotter temp.
Press the iron firmly against the solder pad AND pin of the socket. Wait half a second after you see the pad face turn to liquid and then add your solder. Watch, the moment you see the solder puddle shrink for a second, move the heat to the next pad. When the puddle shrinks, the solder has flowed to the other side of the board. Go ahead and check. See how you just soldered both sides of the board at once? Nice job!
Once the heavy plane traces are done, lower your soldering iron temp and hit all the rest of the pins on the SIPs.
Check your work on the component side of the board and make sure each SIP pin is soldered on both sides. If you have to touch up a solder joint on the component side, you are going to be VERY thankful you used SIPs rather than closed sockets!
Use your meter set on the continuity mode (beep mode), and check EVERY socket pin to the place it runs to on the board. Don't take a shortcut here. Do every one.
Also check each adjoining socket pin against the next to make sure you did not accidentally make a solder bridge.
Clean the flux left from the solder with isopropyl alcohol and an old toothbrush. I know, you probably don't have to, but it is the sign of professional work.
Another marvellous super detailed guide. It's interesting, I learned such lot of things from your tutorial. Great work.