Here is my video of me fixing my 905 electronic cigarette. The Sucker fell of the desk onto the atomizer knocking out the whole top. It took a hard fall and the glue inside it became weak over time. This is not anything related to the 905 itself glue does that.
YouTube - Fixing a DSE 905 broken top peice Well done super strong and cheap
The sucker is Super strong now, EPOXY SEALED, Much better then the way it was before.
Not only sealed nicely but you will next ever get the wobble from it ever again.
i have been soldering for years and i see a few problems with those video's now if your doing a microprocessor everything they have said is 100 percent true. But if your soldering individual wires tinning the iron is only one of the steps to prevent failure.
Tin the iron the board and the wire. when you do this a tap will do ya. No need to hold due to oxidation because you have done all 3 steps to remove it ahead of time.
i have heard horror stories about people burning traces on boards and such waiting for the heat to melt solder. A good solderer can solder a micro board with a 40 watt iron with ease. Although a good solderer would only use whats needed for the job because too much heat can ruin things.
Rule of thumb is bigger is not always better with soldering. for 90 percent of your jobs a 12 - 15 watt will do ya. Especially if your new to soldering. Its also suggested to practice on some old broken electronics, just soldering wires to diff places to get used to it.