weird soldering thing

[MattL]

Hi everybody, I wonder if anybody else has this strange thing that happens to me from time to time. Normally my soldering goes just fine, but on occasion something strange happens. first let me mention that I've been building for around four years and have had around eighty successful builds. I generally feel experienced and confident about my soldering ability. I use 60/40 rosin core solder from Radio Shack, I use the Hako 936 at around 700 degrees. It usually works great, but while I'm more than aware of tinning surfaces before I solder, using a bit of solder to de-solder etc., sometimes it behaves very strangely...old solder doesn't want to melt even with tinning, the tip wants to stick to the solder sometimes, as if I were trying to solder while the iron is cooling. No amount of cleaning the iron, tinning anything, or varying the temperature slightly (which I only do to troubleshoot) changing tips...nothing helps. It occurred to me that maybe some oils from my hands are causing it...
Any ideas, or has anybody else dealt with this problem? It's like all the settings and techniques are the same, but it's just not working. Thanks!

[pickdropper]

Try adding a bit of flux.  That can help a lot.

[wgc]

Flux can help a lot, but it sounds like the kind of thing that happens with pads connected to large ground planes and fills.  You might need a little more heat or wattage in those situations.

[jimilee]

Happens to me from time to time,it's like the iron is cooling down and heating up and you catch it on a cooling cycle.

[jeffaroo]

i had a pos ebay iron and had that problem. my old neighbor opened it up and somehow changed the cycle swing. almost as if he tightened up the on/off span. loved the iron after his tweak. i wish i knew what he did

[MattL]

I had tried the flux, but it didn't help much. Still, I'm relieved that it's not just me! Thanks everybody!

[pickdropper]

I had tried the flux, but it didn't help much. Still, I'm relieved that it's not just me! Thanks everybody!

If the flux didn't help, then I would bet on wgc being right about it being a ground plane.  What kind if tip and temperature setting are you using?

[Guitar Master]

I doubt its your hand oil, I was actually taught that cleaning off the iron with oil on your finger is the best. And its probably just the iron in its cooling cycle

[wgc]

If not flux or ground plane issues, it might be something flaky with heating element or intermittent cord/connector, etc.

Take apart the hand unit and give it a visual once over, I think spare parts are available pretty easily.

[juansolo]

I had that and the element in my iron was packing in. Stuck a new one in there and all is gravy again.

Amusing that I needed a soldering iron to fix a soldering iron... Luckily I have two.