For some people (e.g. this author) solder wick is a tool of last resort. Unfortunately, solder suckers and vacuum pumps lose most of their utility when you move from through-hole to SMD components, forcing us to use the dreaded wick. For those of us in this mindset, [nanofix]’s recent video which we’ve placed below the break on tips for solder wick could make desoldering a much less annoying experience.
Most of the tips have to do with maintaining proper control of heat flow and distribution. [nanofix]’s first recommendation is to cut off short segments of wick, rather than using it straight from the roll, which reduces the amount of heat lost to conduction along the rest of the length. It’s also important to maintain a certain amount of solder on the soldering iron’s tip to improve conduction between the tip and the wick, and to periodically re-tin the tip to replace absorbed solder. Counterintuitively, [nanofix] explains that a low temperature on the soldering iron is more likely to damage the board than a high temperature, since solder wick getting stuck to a pad risks tearing the traces.
[nanofix] also notes that most boards come from the factory with lead-free solder, which has a higher melting point than tin-lead solder, and thus makes it harder to wick. He recommends first adding eutectic lead-based solder to the pads, then wicking away the new, lower melting-point mixture. Other miscellaneous tips include cutting a more precise tip into pieces of wick, always using flux, avoiding small soldering iron tips, and preheating the board with hot air.
We’ve seen a couple of guides to desoldering before. If you’re looking for more exotic methods for easing the task, you can always use bismuth.
Making Solder Wick Less Painful
I’ve been hesitating to replace my solder-sucker with a real vacuum pump for so long, that now I don’t need either of them anymore because everything is SMD. :D
Naaa, not really true. I like to work on vintage computers. But I became so proficient with my solder-sucker that I just can’t warrant the purchase of a vacuum pump.
Yeah, been using my favourite type of solder sucker for a long time, for thru hole and SMD cleanup as well as chemtronics wick.
The only vacuum pump desoldering gun I’ve ever got in with was an OK Industries one, they are not cheap and I doubt my employer would have been happy if I’d taken it when I left.
I have an OKi solder station from when they were merged / bought out whatever with metcal so metcal tips fit it fine
so we were in a merger and some equipment, mostly broken got transferred to us, and I was going though it and found this thing, its a iron with metcal tips, a sucker gun that transforms from pistol grip to pencil grip and a set of tweezers, it was broken.
So I say “hey boss man there’s this kit, its valued at whatever was on the spreadsheet, but its totally dead”. He says I don’t want you wasting your time fixing old junk just toss it out (neglected to say where)
I take it home and pull it apart, put less than 50 bucks worth of effort and parts into it and a little bit of glue (if you pressed in a tip too hard the cable boot would pop out) and its been in nearly daily service for almost 8 years now.
On that same mentality of “its old junk don’t waste your time with it ” I’m also running a TDK-Lambada UP20-10 power supply connected to a surplus GPIB remote control while sitting at my Kewaunee 3 tier ESD safe bench with a full stack Kennedy tool box next to it
The toolbox was especially funny cause when that got kicked out of house the maintenance manager scoffed and said if you can fit that in your KIA (2006 rio) you can have it for free … he didn’t know it was 3 boxes stood on top of each other, though with the back seat down and passenger seat full I still drove 40 min with my knees against the dashboard
this is an older picture but still
https://forums.atariage.com/topic/277693-show-us-your-bench-and-i-got-a-new-toy/#findComment-5671450
Looks like it never sees someone working there…. :-)
yea it never really looks like that, that was the day I cleaned it
For multi-pin smd parts I use tin-bismuth solder to remove them. Melts at around 140 C, put an excess on all the pins and keep it molten. Much less likely to strip traces off the board. Then use a vacuum solder station to clean off the excess.
I’m gonna throw out the best piece of solder wick advice I have ever learned.
Press the tip on the wick…then pull the wick up and back over the top of the tip. The heat above the joint will cause the solder to flow upwards…so it is wicking instead of dabbing the solder off.
Credit goes to the late John Dunn. My electronics instructor.
Yeah, if you have a LOT of solder to remove, you can put the wick down with a bunch hanging out the other side, put the soldering iron tip on it, and then pull the wick through, drawing solder out along the wick length. But be really careful doing this. It’s an easy way to rip off a pad/trace.
Same thing holds for particularly terrible through-hole cleanup. Strip 10cm of stranded copper wire, twist it together tightly with your fingers, and see if you can get it through the hole when it has some extra solder on it to increase heat transfer, then push it all the way through, soaking out solder as it travels. As long as you don’t end up sticking the wire in the board and manage to get it free, you can extract a lot of solder from even the crabbiest of ground planes.
if you have problems with solder wick, you probably bought something “solder wick shaped” on alibaba
It works fine if you use plenty of rosin flux.
Flux is 100% key to good wicking, dip the wick in flux if you can or smother it with it depending on your flux type and it wick like a dream
Flux is 100% the secret sauce they don’t tell you about when you’re taught to solder, except as an offhand comment. With a tube of tack flux, anyone can solder good (not that using tons of flux makes you ‘good’ at soldering).
Seriously. When I think back to using a way-too-hot Radio Shack firestarter with no flux, it’s no WONDER I thought I couldn’t solder back in High School. Variable temperature iron + a syringe of rosin feels like a cheat code.
When I first started soldering I bought on aliexpress, like 50 meters of solder wick for $10, many times cheaper than those “premium” ones, and I got frustrated because it didn’t suck ANYTHING.
BUT now I know there is not a single reason to buy expensive ones, all you need is the cheapest wick you can get, and the bottle of liquid flux, might be cheap as well. You just do a quick dip and use it, it works better than any of those premium wicks out there.
let me look at my wick, ah yea Chemtronics 50-4-100, yea that’s 85 bucks on digikey
Has always sucked, will alway suck, have to add about a half gallon of flux most of the time and by its nature is very abrasive, even on brand new boards if you press too hard
granted that 85 bucks has lasted me about decade but even cheap crap doesnt really work all that much worse, its wick … flux and practice is key vs quality
I have purchased great wick from Aliexpress that works as well as the name brands. The key is don’t buy no clean, lead free fluxed or heaven forbid unfluxed wick. Get wick with activated rosin flux.
The other “tricks” I learned long before SMD was popular, but they still apply. Double the end of the wick over before wicking. Gives more heated mass and more surface area to wick. Also, Don’t use a tiny tip on SMD. Soldering and desoldering works because you transfer heat from your iron the the connection. A tiny tip doesn’t have enough mass and the tip and connection cools instead of melting the solder. Finally, as mentioned prevously, use a little 60/40 RA flux solder to wet and melt the connection before wicking. Do these things and wick will be your friend.
Looking forward to Chapter 5.
When I didn’t have flux (stuck in the “use what I’ve got” mindset for too long) I found that sometimes spreading the braid out helped a lot. Grab two points on it, near each other, and push them together gently. The weave should open up a bit.
Now that I have a decent iron, and flux, I haven’t had to do that very often. I’ve been using a fluxed braid, but I find that I don’t use it fast enough to keep it from drying out, and it works just as well as the non-flux stuff I’ve got left over from when Radio Shack was still around. Now when I want flux, I just use a bottle with a blunt needle to apply some in liquid form.
If you use the braid straight off the roll, keeping a small bit of solder on the end of the braid when you cut off the used portion is quite help too.
Best solder wick I’ve found was the shield from old RG59 coax and a bit of rosin flux. Salvaged a ton of coax from office network upgrades years ago and I’m still using it.
Now that’s a good and proper hack. I love it. Coax shield.
Now speaking of cheap wick, is there any reason that wick made of CCA wouldn’t work well? Or even the dreaded and scandalous copper coated steel wire that was showing up in alligator clip jumpers? That would reduce the excessive conductive losses when wicking “straight off the roll”
Lead free solder “eats” the copper off of copper clad aluminum (CCA) really fast. That leaves you with aluminum, which doesn’t stick to solder.
CCA sounds like a really bad substitute for solder wick.
I get my solder wick from old stp cat5 network cable. The older, the best shielding mesh. Soaked in rosin it works like a charm for what it is: a recycling habit.
Pro Tip: pay for the good stuff, buy Gootwick. You can thank me later.
This is all just wrong… keep the wick in a spool and use its tail. Pu the tail on top of solder (pis or pads). Press it into the solder with the iron, and pull both the iron and wick away. It wicks the solder quick… how could you over heat a pad? I use wick to clean used pcb to like-new. I use wick to mount tiny qqfp pins (just melt solder all over them, wick it all off, then check for shorts and use more wick if you have any shorts). It is very easy to use… I don’t see the problem.
Yes to flux anywhere and everywhere, especially on seldom used braid. I still work on vintage musical gear. As for suckers I’ve never liked the single shot ones, cock and fire over and over. A heated hollow tip with a baby enema bulb is often encountered but with poor results, shake whilst holding still and lift to squeeze as well with little suction on release. Player pianos with their vacuum tech had me make a foot bellows to make a short but powerful burst with no pad lifting kickback, hands only hold the tool. Hose goes from the floor to the former enema bulb. Desoldering that isn’t a pain in the butt. Cheaper than any vacuum electric powered tool.
I need to see that bellows system. Got a link!
You must pull the stranded braid exceptionally tight to start and tack a drop of solder near the frayed end. Trim off the fray. Now, that the braid is exceptionally tight, it’ll wick as well as a professional vacuum desoldering iron without needing any flux.