I have just searched for ‘soldering’ and didn’t find any threads that really answer the questions I have, and most of the stuff I find on Google is pretty much useless, so I hope it’s ok to post a new thread about what must be a fairly well-covered topic…
Basically, I’ve just recently gotten really into Arduino (after having an UNO since November) and finally got round to buying a soldering iron. However, I haven’t used one since my school days, which must be about 8 years ago now, and even then I didn’t do a lot of soldering. Plus we were taught barely anything anyway, so I’m quite rusty.
I bought myself a Weller WTCP 51 station, which is a step up from what we used at school (though I’d imagine a long way from a professional iron). The iron and tip combo it comes with gives you about 370C (700F). I’ve used it to assemble two Proto Shields today, which is where the first of my problems come in.
Around the contact pads I’ve soldered the board (and on the pad and joint itself, actually) has some yellowish stuff on it (please see photo attached), at first I thought it was the board itself melting slightly or delaminating, but is it flux residue? And if so, is it bad having that much still stuck to the board, given that it’s acidic? I’m using some RS own brand solder, it’s Sn60 Pb40 0.75mm No Clean, probably with a rosin core (it doesn’t say so on there but it’s cheap and was branded as an ‘essential’, probably meaning not at all specialist and therefore just standard, common or garden solder).
Also, the tip of my iron was tinned when I got it (i.e. the last 5mm of the tip was silver whereas the rest was duller) but after a little bit of soldering (and loads of cleaning, I dabbed it on the sponge after basically every joint made because of the build up of brown/black stuff on it) the silver area is a lot smaller. Am I supposed to just keep applying solder to it to tin it (even though when I did that it just stuck to the bits that are already tinned and turned into a big drop of solder)? This is something I was never really taught. I have some tip tinner/cleaner so I just placed the tip of the iron on it, but now there are big yellow stains on the cleaner itself (which I imagine will end up back on the iron if I use it again), so I don’t really know what’s going on, I’m completely clueless about this stuff.
Finally, is 370C/700F a good temperature for soldering or would 310C/590F be more suitable? This iron’s temperature is set by the tip you use, you see, there’s no dials to adjust or anything, and tips come in 310/370/425/480C, but it came with a 370C tip. I guess the answer to my first question would answer this, though; I imagine if the yellow stuff is flux residue then the iron is fine, but if it’s the board delaminating/melting then it’s too hot!
Thanks for taking the time to read this, any help would be very much appreciated.