Ignoring the flux during regular PCB soldering, I was curious as to whether core in the solder wire is required to properly wet the iron tip. I saw someone saying that for drag soldering the solid-core wire was better, but in that case there is no flux when you wet the tip or deposit solder onto the tip. The flux must do something to the tip right? Although, I have heard that active flux does shorten tip life, I am not sure if it does anything beneficial for the tip.

 

I can't say I've ever seen any non-flux electroic solder?, I certainly see no reason to want it? - if you're 'drag soldering' you're applying solder directly to the tip, and the flux evaporates anyway.

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I've seen solid solder w/o flux, but it doesn't work well at all. You have to add flux of some type else you have grainy, cold-soldered joints (especially lead-free, which kinda looks grainy anyway, flux or no flux.) The flux is used to cut through the oxidation and such so that a proper joint can be made. I don't recommend trying to solder without flux.
JB

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Nothing is impossible for the man who doesn't have to do it himself - Weiler's Law

 

I'm not talking about soldering without flux (the flux is applied to the PCB). I am talking about wetting the tip with solid core solder wire.

This is where I am confused, isn't the flux required to remove the oxides on the tip so that the solder can properly wet the tip? But I have also read that active fluxes oxidize the tip more shortening tip life (remember than the flux is supposed to remove oxides). But then again, the tip is so hot that the flux evaporates?

 

Use normal solder - I see no reason not to want to, if your tip only lasts 17 months instead of 18 months?, do you consider that a big problem?.

I'm also doubtful the 'drag soldering' technique will work unless you use flux cored solder (or apply external flux to the tip), as the solder won't 'stick' to the tip properly, so when you try to 'drag' it will tend to come off in one big blob!.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

If all you interested in is making sure your iron's tip is sufficiently wetted with solder, try tip cleaner. It comes in a small metal container about 1 inch or so diameter. Basically, it's solder powder suspended in a hard flux base. You simply heat up your iron and dip it in the mixture. When you do, the flux and solder melt onto the tip, tinning it automatically. Here's an example.
JB

__________________
Nothing is impossible for the man who doesn't have to do it himself - Weiler's Law

 

I'm just curious about the details in soldering process.