#108

  • 40W is on the low side. it’s fine for small boards/repairs/projects. here’s a thing: wattage doesn’t exactly determine how hot the iron can get (900F is plenty hot), more how quickly it can heat up - this translates to temperature consistency when working with bigger parts / many parts in a row… or tasks like desoldering a big part.

  • it is probably not really temp-regulated, just a voltage conttrol. if you are gonna solder lots of stuff, it’s really worth $100 to get a regulated solder station - it will be easier and over time will likely save some parts from destruction.

  • if it really came with an enormous chisel tip, that’s not good for electronics. you want a chisel tip closer to, i dunno, 1/16" wide or something. (pointed tip is a little less useful.) this is the cheap and effective upgrade.

of course tools aren’t everything, and a simple tool will get the job done. practice is probably the main factor.

re: desoldering pots, it’s just hard. legs are already trimmed and will get messed up more. there’s a real risk of damaging traces. so “don’t do it” is pretty sound advice.

if you are gonna do it, a solder vacuum is a great tool. but it will amplify the risk of lifting pads. and like anything else it takes practice to get good at. also, they are not made equal. for some reason a thing called SOLDAPULLT appears to be universally well regarded. (it was the only usable one in our shop when i was growing up.)

as far as tips or tricks, all i’ve got is that it’s sometimes (counterintuitively) helpful to use large blobs of solder to hold heat. 1) it can actually make it easier to vacuum a leg. 2) you may be able to keep all the joints “wet” by going quickly around, and then just lift the part out. this technique is easier with two irons and a helper. in principle it’s the poor man’s solder pot.

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#109

i use that narrow one on the right from this pack:

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i think you’re right. im not gonna worry about it for now. then get a better iron and a solder vacuum eventually. i appreciate the help.

also thank you for explaining the heat consistency. that makes sense

#110

cool. well if you have that whole pack it’s probably worth experimenting with the smaller flat tip, or the cone. you can get more surface area in contact with the part.

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#111

That might be the same iron I use (though it looks like there is a higher wattage one, too). I keep mine around 4, a little lower for smd and a little higher for pots, switches, etc.

For flux I use something similar to this though I don’t remember where I got it or the brand. If you get a flux pen just make sure you get “no-clean” and not “water soluble”

If you plan on doing a lot of projects it might be worth looking into using no clean solder for some parts and water soluble for others (though this is a separate conversation entirely!!).

One other thing - make sure your tip is clean when desoldering. If fresh solder doesn’t immediately stick then it’s not going to desolder. I recommend using one of those steel wool type cleaners over the wet sponge method but that’s up to you.

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#112

I’ve always wondered about this. I’ve been soldering then in my boards thinking the more there is the better for stress relief… But in these vertical pots and encoders, maybe not really helping? On the right angle DC power jacks, soldering the 3rd blade for stress seems essential, since plugging the cord in give lots of sideways force.

How do others feel about soldering retaining tabs on parts?

#113

One caveat, if your pots don’t use washers/nuts for security to a front panel of some kind I would advise to solder them down for security for sure, I’m mostly speaking as someone who pretty much is always fastening them to a front panel with washers/nuts.

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#114

Can anyone share what you do to clean the boards out of flux? Especially with loads of smd components like Mutable ones? I tried to use very soft brush + isopropyl alcohol which makes things better but still everything is kind a sticky and not fully cleaned.

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#115

I use a toothbrush with 99% iso and do a couple passes. If there aren’t any switches or pots on the board yet, I soak it in a little container and then scrub. If you have a nice nice PCB (Oshpark, etc) they can take a some action and be fine.

I recently had to shelve a Paia Fatman kit after months of work. Poor board took a beating. It was a pretty oldschool single sided board and pads were getting ripped left and right while trimming leads. I learned my lesson!

The dream would be to have an ultrasonic cleaner tho… one day!

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#117

Maybe I just need to try harder I am not sure, I use same things but either I use too much flux or I use wrong alcohol not sure but mines are always stay sticky, maybe need to be more patient in cleaning as well:)

#118

To my experience, 99% isopropyl alcohol works significantly better than 70% IPA. Also, in most cases it is possibly ok to use a medium soft brush as well. And what usually makes the biggest difference for me with stubborn residue is that I wipe the cleaned areas with a little piece of freshly IPA soaked cloth, or cotton bud in very narrow places, after every brush clean (although I usually only do that before there are any sensitive parts installed). That seems to soak up most of the remaining residues. After that I give it a quick final brush with a clean and dry medium hard brush to finish off the procedure.
Different solder (or flux for that matter) may require a slightly different approach. Some clean very quickly and with almost no hassle. Others are quite stubborn. Adjust your technique accordingly and you’ll get good results.

#119

Usually with solder braid I put it over the part I want to desolder, and lay the entire end of the iron down parallel to the braid over it. It definitely takes a second. I’ve seen people try to use the very point of the iron to desolder with braid, which might be your problem?

#120

Thank you very much for feedback, I should definitely try to add ipa+cloth step.

#121

If, hypothetically, one was soldering away, lost in a semi-meditative state while brandishing the iron and happened to solder some header pins backward, and then proceeded to clip said pins and remove the bits-n-pieces, and upon doing that, found that he/she had lifted some pads- should that hypothetical person scrap the PCB?

(Also, if we ever do a standup night here on lines, this project would make a killer bit. Remind me to tell the story later)

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#122

Totally depends on the circumstance, might be something you could fix with solid core wire as jumpers if it’s through hole. Was this another colour pallet PCB? Pics?

#123

Nah, this time it’s a Sweet Sixteen mk ii. It’s not as bad as I feared it would be, inspecting it this morning. I dunno, thoughts? Think she’ll fly?

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#124

No harm in soldering them back in and then tracing them out (checking continuity between the header pin and the destination of the trace coming off it). Worst case as @kbit mentions, you may need to run a jumper wire or two if you’re not getting continuity. Check the schem, too, it’s possible a couple of those teensy headers aren’t going anywhere, in which case, lifted pads? Who cares! The circuit won’t.

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#125

I wouldn’t scrap the PCB, you can always just run jumper wires between what the lifted pad was supposed to connect, though having the schematic for what you’re soldering makes that a lot easier.

#126

Maybe it will just be a Sweet Thirteen or something :laughing:

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