From Reddit saved comment — r/AskElectronics, u/Dio_Frybones, Jul 19 2020 https://www.reddit.com/r/AskElectronics/comments/htqk24/learning_to_solder_are_these_cold_joints_link_in/fyipn13/ Comment on: Learning to solder. Are these cold joints (link in post)? Some of the joints dont look great. What most people call a dry joint is when the joint doesn't look shiny. Often caused by moving the parts before they solidify. Its the shape of the joint thats problematic, and where the component lead meets it. Its the difference between sticking a pencil into an apple (bad) vs putting it into a jar of honey and pulling it out slowly. The solder should ramp up to the lead. Same at the edge of the pad. It should be a concave profile. You'll get advice to heat the component lead. That's correct if you are just trying to solder the lead and nothing else. What you need to do is heat both the lead and pad simultaneously and APPLY the solder to the component lead. Not the pad. Because if the component lead isnt hot enough to melt the solder, you are going to get a bad joint. The size of the solder is quite important here. It needs to be fine enough that you have enough time to control exactly where it is going. Too big and you'll just get blobs. If you are still struggling, you might find that it's worth cleaning the leads. Keep a small piece of emery paper or similar nearby and wipe the lead before soldering. Don't touch anything you plan to solder with your fingers. You can also clean the solder. Finally, people on here swear by using flux. While I agree it can make SMD work go easier, for routine soldering you should never need it to get a good joint. I'm talking 40 years experience here. Don't buy stuff you dont need. A decent iron with a decent clean tip. Good quality rosin cored solder. Err on the side of being too fine. Some way to clean component leads and pcb pads. Personally I'll frequently just use a plastic scourer and wipe any residual plastic bits off before soldering. That's about it. For 95% of applications you dont need to even worry about temperature control if you've got the right sized tip. But bear in mind that occasionally when soldering larger components, or pcb pads connected to large earth planes, you need more heat. Often that's more a matter of tip size than temperature anyway. I find that I can get away with a fine pencil tip for most of what I do, and use a little portable gas iron when I need the nuclear option. These are absolutely worthwhile if you plan to do anything requiring a bit more heat.

From Reddit saved post — r/AskElectronics, u/Scarycoast, Jul 18 2020 https://www.reddit.com/r/AskElectronics/comments/htqk24/learning_to_solder_are_these_cold_joints_link_in/ Hello! I am learning to solder and bought a little kit off amazon for my first attempt. I’ve only soldered a couple of resistors and some other chip on so far. I’m having a hard time with the resistors, I think due to them being so thin. [Here are some pictures of the soldering. ](https://imgur.com/gallery/uzkB224) Are these cold joints? Will I need to redo all of these? Thank you!