Tips on soldering and unsoldering train stuff. . . (updated 12-24-2007)
The issue is usually how to unsolder something. Almost always, the problem with unsoldering something is the lack of flux in the existing joint. This is where a bottle of liquid flux is invaluable. In the electronics repair business, we typically paint the old joint with some liquid rosin flux with a small brush.
Using a larger iron is better for unsoldering. A smaller iron takes longer to heat the object, that time translates to heat migration and the area gets overall hotter than using a larger iron. I use an iron of 45 watts for everything. Remember, with soldering, the object is to get in and get out quickly. By the way, I never burn ties.
It is kind of like a house painter, they will use a 4 inch brush for things you and I would use a 1 inch. They have the technique and skill honed to use the larger tool. Soldering is an art, you have to develop and practice the technique.
Liquid soldering flux
From GC Electronics Completely non-corrosive liquid solder flux consisting of a solution of special rosin in alcohol. Contains no traces of acids or chlorides and is completely safe to use on even the most delicate electronic equipment. For electronics applications. $6.95
Here are the tools I use to solder everything from a decoder wire to an HO rail. There is NO adjustment on my Iron, by the way. The advantages of the station is the thermostatic control and the sponge. Simple soldering irons typically have poor or no thermostatic control and get hotter and hotter the longer you use them as evidenced by their burned up tips. The tip in my Iron is 5 or 6 years old. It does not burn up, and is easy to re-tin. I cannot tell you how many times I left it on all night. My soldering station is an old TC202 Weller. They can be had on Ebay, I recently purchased a spare in near mint condition (compared to my old unit) for less than $40 including shipping. The tips are still available.
Soldering iron tips wear out much faster when you use acid core solder like when hand laying track
Too bad we don't have a video of the time I sat on my soldering pencil in a computer room about 20 years ago, burned a hole in my pants and my butt!
These are the primary tools I use to do all the soldering on my layout. The two larger rolls of solder are there for illustration purposes. I only use the tiny stuff on the left. The yellow disk is solder wick, a copper braid useful in removing excess solder from a board. Been years since I used it.
The most useful tool for soldering that I have is this marvelous tool.
A brass solder sucker, only time I use this is when I am removing a part from a printed circuit board, or I am cleaning up excess solder on track joint or feeder I removed.