Solder won't flow right ...

[pcb rookie]

Practice builds confidence. I did more soldering lately and got better at it overtime. I did some pretty clean PCBs lately. Most days the solder just flows through easy peasy. Every now and them, I hit a project that the solder just won't flow right. Today was one of them. The solder would stick to the lead instead of flowing though/on the contact eyelet or just bunch up. I stopped, cleaned and tined my tip. Cleaned up the PCB with IPA. Tried again, same. Applied some flux paste (usually don't). It got better but barely. Flowed perfect in the end when I got to transistors and trim pots ...

Any one as leads on what's the cause when solder just won't flow?

When do you do or adjust when that happens?

FYI - I use 60/40 Aims .032 diameter solder @ 400 degrees average. I tin my tip between every 2-3 solder and keep in clean.

 

[djmiyta]

^great point there. I didn't realize that the 60/40 isn't eutectic...using an eutectic solder made a huge difference for me, personally.

I'm a SN100C man myself...not a big Pb fan. Concerns and such. It's a bit more of a pain to desolder, and melts at a higher temp, but it's eutectic and flows very well. Much better than the sn-ag-cu stuff that I was using before.

eutectic? holy shit on toast! I had to look that word up. Never heard that word ........... EVER! love expanding my vocabulary

 

[bowanderror]

eutectic? holy shit on toast! I had to look that word up. Never heard that word ........... EVER! love expanding my vocabulary

I'm always interested to find words that are (mostly) unique to one particular field. Here is another fun one for you: Disproportionation

Ever watch the small bubbles in the head of a beer combine into ever larger and larger bubbles? That's disproportionation. The science of beer foam is pretty fascinating in and of itself.

 

[djmiyta]

Ever watch the small bubbles in the head of a beer combine into ever larger and larger bubbles? That's disproportionation. The science of beer foam is pretty fascinating in and of itself.

All I read was beer