Through hole soldering problems

[KL27x]

I agree with eKretz. In general, I match the tip to the work by selecting the largest possible tip that won't cause problem.

If some of your holes are connected to the ground plane, directly, or with insufficient relief, this can cause a huge problem that a skinny 1mm bevel or the like can't even touch (sans presence of a board pre-heater). Huge tip, high heat, clean tip, then hit it fast.

[orin]

"Quality Hand Soldering and Circuit Board Repair" suggests that you place the solder next to the wire/pad being soldered and apply the iron tip to the solder.  This allows the solder to melt, the flux to release and flow over the joint before the joint heats up and oxidizes.

Certainly, applying the iron with a low thermal mass tip to the joint without flux can cause problems as the joint heats up slowly and oxidizes before the solder/flux melts.

Adding lots of flux will help.  Even the paste flux that Radio Shack sells is OK - don't know if it's still sold in the stores.

[Stuartambient]

Figured I'd update the thread.  I tried the larger chisel but really didn't work for me.  Finally tried a hoof, about or slightly wider then hole and it was a huge improvement.  Able to get the edges to the plated ring and lead and heat enough to complete the joint in a few seconds.  Also using slightly narrower solder and additional flux.  All 3 make a big difference.