Soldering or Melting paste

@dazza 

most of the solder sticks to the iron or drops on the floor/table

It sounds like your basic soldering skill is in need of a correction. There should be very little solder on the iron. Correct technique is to heat up the parts with the iron then touch the solder to the parts, very little to no solder gets on the iron. If some does, stick the toip into a brass cleaner like this. Also use either paste or my favorite liquid rosin flux.

You might benefit from watching some Youtube videos about SMC soldering. Good luck.

@zander 🤣  and Yes YT I go 🤠 

Also I need to close the current 30 tabs open in my browser 🤩 

Hello @zander, I'm new here but I thought I might have a couple of details to add on this subject.

I've just moved out of the very beginning phase of learning SMD work. I had quite the issue with soldering the infernal stuff at first, but I got clued in by another hobbyist which I had the fortune to cross paths with that if you're going to be doing some SMD work, especially in the beginning, it helps to use a really thick or sticky flux paste if you're hand-soldering because it will help hold the part in place while you get started and because it will do a good job of helping the solder flow with less lumping and bridging.  Of course a liquid flux will work just about as well, but it won't hold the piece in place much. I'm a particular fan on Chip Quik solder paste and flux paste, but any good-quality paste will do just fine.  Most solder pastes include a decent flux, but be wary of getting too much solder paste at one time because most of them have a pretty limited shelf-life even if refrigerated between uses.

I heartily agree with the YT video suggestion, videos are where I picked up much of my technique, both with an iron and with a hot air wand.

Happy soldering!

Old Techie

@old-techie Cheers, thanks for your reply

@old-techie let me pick your brain. 

Would you prefer to use the hot-air gun or try a hot plate? 

@dazza Hello!

For me, plate or wand depends on how complicated the board is and how small the parts are.  I tend to favor the wand both because it lets you concentrate more on the parts that need more heating while sparing the smaller parts that are heat sensitive, such as diode, LEDs, and transistors, and I have more experience with the wand.  So far I've mostly used minimum air flow with the wand so that parts aren't blown around much, and I avoid using air that's really hot.  I stick around 210 to 235 degrees most of the time, though I know guys who go as high at 270, but I'm afraid I'd cook something if I went that high.  Once the solder melts it tends to pull parts into alignment with surface tension, and using a good sticky solder paste to tack the parts down helps keep them from shifting as much so using a higher airflow might work.  I tend to be conservative with my SMD stuff.  I've stayed away from the TSSOP and similar-sized chips because their lead pitch is just too fine for my sloppy hand to apply solder paste without making huge globs between pins.  If you have a fine hand, that might not be an issue for you and if you're using a solder stencil, it's generally not an issue at all.

If you're doing a more complicated board, that's when I'd really break out the hot plate.  If you don't have an air wand there is no reason to avoid a hot plate either, it's just that a wand is my personal preference.  Hot plates work very well, but they're not very forgiving of rough handling.  Tilting a board too much or jarring it while removing it from the plate is a frequent source of shifted components. Using a hot plate tends to avoid "tomb stoning", where uneven heating and cooling can stand some two-terminal parts right up on end.  I've never seen that happen myself but I've heard several people who have done many more boards than I ever will say it happens sometimes with wands and uneven heating.  It can also happen with cooling a board too quickly, but that's not as common.

I guess which to use really boils down to two things:  Use what you have unless you have the spare cash to buy a new tool and it depends on how delicate a touch you have with handling small items and using paste.

Remember when using the plate method to be careful about overheating the semiconductors, it's really easy to get impatient waiting on the heating and turn the heat up too much.  While people can and do use a frying pan full of sand (to give a more stable surface and to even out the heat transfer because most plates are just on-off type devices) on a regular stove, make sure you either use a temperature stabilized hotplate or use an infrared thermometer and find out ahead of time which setting on the plate corresponds to which temperature and how long it takes your setup to heat all the way up, that also makes it easier to try and follow the soldering profile recommended by the manufacturers.  Doing that helps make it even more likely to get good results.

I apologize in advance for the sloppy organization of my thoughts, I sometimes have a bit of an issue with that.

Have a great day and happy soldering!

@old-techie Sand? I can see that

Interesting