Desoldering braid or desoldering wick is finely braided strands of copper wire that contain a flux. It usually comes supplied on a roll. Its prime and I think only use is to remove solder. Don’t be fooled into thinking that all desolder braid is the same, it’s not. The best desoldering braid will soak up solder like a sponge; unfortunately some of the others are all but useless.
To use desoldering braid you simply heat up the joint that you want to remove the solder from by applying your soldering iron tip. When the joint becomes molten you just feed the braid into it while still applying the soldering iron. You will see the desoldering wick soak up the braid and vanish from the joint. You then pull the braid and soldering iron away and you should be left with an almost solder less joint. Then you will need to cut off the used section of the braid. Sometimes you may have to heat any remaining solder and try again with the wick until it’s all soaked up.
If you don’t have desoldering wick to hand you can make an alternative homemade desolder braid. You may have noticed that desoldering wick looks a bit like the screening on coaxial cables. That’s what we’re going to use. If you’ve got any around it’s used on audio, microphone, satellite and TV aerials. Cut a couple of inches off, strip off the plastic, pull out the central core then apply some flux. Make sure it’s the electronic kind not the plumbing stuff. Without the flux it won’t work very well.
I get mine from Amazon and if you look at the reviews for it you’ll see I’m not alone in thinking it the best desoldering braid, especially considering the cost. Some of the others I've tried didn’t work particularly well if at all. I think the main reason is the flux that is use or the lack of it. If you find your wick underperforming try applying a little extra flux. Try this Liquid Flux for Electronics 30mls. The Amazon Electrosmart product must use a superior type. It is 2mm wide which feels just about right to me and you get a decent 3 meter roll which lasts for ages even if you’ve got loads of desoldering to do. All in all I can’t really fault it and for me it easily attains the title of the best desoldering braid.