Choosing the right kind of coax connector.

There are some things to keep in mind when buying PL-259 or SO-239 coax connectors. If the material holding the center pin is white or clear, DON'T BUY IT! I have found that these materials will not tolerate much heat from soldering. They will  melt and come out of the barrel. The best type are connectors that are either brown or baby-poo yellow. These stand up to heat very well and can even be reused. I try to buy Amphenol brand coax connectors if possible. I think they are the best. Beware of buying coax connectors at hamfests. I have seen some that are factory rejects and some of the center pins are undersized. This causes problems in getting the center conductor of the RG-8 coax to fit.
If I ever need to cut off a coax connector from a cable, I try to leave at least an inch of coax sticking out the back side of it so I can grab it with a pliers while heating up the center pin and outside of the barrel with a propane torch. I have a small torch head that is on the end of a rubber hose and it has a sleeve that you turn to turn on the gas. The other end has a cap that fastens to the propane cylinder. It was rather expensive to buy, but very handy. You can regulate the amount of heat more precisely than with a standard torch head.
Once I get the old piece of coax out, I set it aside to cool for a while. When it is safe to touch, I take a Swedish file and file the area around the 4 holes in the barrel so it is shiny brass. This also gets rid of burned soldering flux. I also use the same file to clean the inside of the barrel of solder fragments and any wire whiskers that may be still sticking to the inside. Once this is all done, the connector is reusable.