Great question, I use mine on 685, I just read it somewhere, but it has worked fine for me
for 2 yrs...

I just did a relay today at 800 just don't leave it on long. Real quick melt

Great question, I was wondering the same thing myself.

400c

I usually keep mine at about 610.

I solder at around 700F. Maybe a tad less for small chip sockets and a bit higher for larger component lugs and older boards.

There really isn't a single, clean cut answer for that. Some people like a lot of heat for a very short amount of time, some people like less heat for longer. It's a bit like a recipe, where you can adjust the amount of heat you need to prepare a dish to tailor it to the amount of time you have to cook in.

I tend to desolder around 400 celsius. Solder around 325.

Sometimes, you have to adjust that, though. If you're desoldering a big pin of a connector that is attached to the ground plane of a PCB, you've got a heck of a lot more to heat up than a single leg of a transistor. So, on ground planes, I go a little higher on the temperature.

When desoldering, I often use a little liquid flux. That seems to reduce the amount of time I have to keep the heat on the board.

You also have to keep your tips in good shape - clean, not oxidized. As a tip wears out, you often have to increase heat a little to keep it operating well. That's a good sign that it's time to replace the tip. The coating on the tips is very thin - you can't just file or sand the old tarnished tip and make it shiny and start using it again.

Find some junk boards to practice soldering on, and find out what works for you!

Don & Jeff suggested 660ish on the pinball podcast.

i do anywhere from 650-700. sometimes a little higher desoldering pesky blobs.

johns words are spot on. tin those tips, boys.

I started at 750, and in replacing a transistor for the first time (previous board work being nothing more ambitious than reflowing header pins) I just barely lifted a trace, so I have dialed it back a bit. Sounds like I should go a bit lower still.

Also, do yourself a favor and lose the wet sponge and instead go with something like this for cleaning your soldering iron:

http://toolmonger.com/2008/11/12/solder-better-with-a-clean-iron/

tip-cleaner.jpg

Another reason there is no correct answer is because things like ambient temperature, humidity level and the temperature of the boards you're working on all affect what temperature works best. Soldering warm boards in a 84 degree house with medium humidity will take less heat than soldering the same cold boards in a 55 degree garage with low humidity. The colder the room/ parts, the hotter you want the iron.

Sometimes a wet sponge is the better choice. I know there are strong beliefs for both. I use whatever works best.