Dragon's Lair Fans - Arcade Lifestyle
General Chat => Technical Area => Topic started by: Superully on June 06, 2010, 12:33:58 PM
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guys, i need some input:
yesterday i had to remove two old capacitors from a pcb which turned out more difficult than i had imagined.
(1) desoldering: i couldn't get the old solder to "flow / melt", although i had done everything i was told to do: temperature at 370°, tin the tip, put some new solder on the tip to add flux to the old solder. it worked at some joints, but there was one which was impossible to get out / off. even the new solder didn't want to stick to the old one, , i even tried cleaning the old solder with a fibreglass pen. i had to give up on this joint :(
(2) soldering: as you know, i'm no expert in that, but i've watched a couple of videos and read some stuff about it. so i put the new capacitor legs through the holes, cut them to the correct length and heated both the spot and the leg at the same time. the videos suggest that you add the solder wick from the other side, because it tends to flow towards the heat, therefore forming a nice little "hill" around the entire leg. this didn't work at all, the solder simply wouldn't melt. then i put it directly on the soldering iron tip and while this worked for the first "connection", it got worse with each subsequent one. at the fourth connection, it wouldn't even stick to the capacitor's leg anymore :(
i feel stupid!!! now it's your time to shine: what did i do wrong, how can i get the old solder to melt and the new one to stick / flow?
one more question: is it possible that the solder wick i'm using is too old: i have this liying around for many many years, perhaps it simply isn't usable anymore. if that is the case, do you have any solder wick suggestions for me?
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bump of the week!
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I doubt your wick is too old, it sits in shops for ages before you buy it also.
You could try applying flux to the area first, you can buy it in the same places you buy the rest.
Also, check if the solder you're using is the new lead-free stuff. I'm not sure about this but it might not bind well with the older solder with lead in it.
I know it's bad for your health and whatnot to inhale the leaded solder but I've never managed to get good results with the lead-free stuff anyway.
For soldering, hold the iron to the trace/leg, and apply solder from the opposite side of the leg (not the opposite side of the board). You might need to "help" it a little by applying a little solder to the trace while heating it and letting it flow around the leg first.
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on a french board, there's a tutorial, to properly desolder using desoldering braid.
Here it is, passed thru google translator :
there are many pictures, this could be helpful :
http://translate.google.fr/translate?hl=fr&sl=fr&tl=en&u=http%3A%2F%2Fwww.gamoover.net%2Ftuto%2Fje-dessoude-%25C3%25A0-la-tresse-%25C3%25A0-dessouder (http://translate.google.fr/translate?hl=fr&sl=fr&tl=en&u=http%3A%2F%2Fwww.gamoover.net%2Ftuto%2Fje-dessoude-%25C3%25A0-la-tresse-%25C3%25A0-dessouder)
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Like liquidx says, leadfree solder sucks bigtime !
I always use the tin with lead (60-40)
and make sure youre using Flux-core solder , that is made for electronics
it has flux inside that helps the solder to flow
http://en.wikipedia.org/wiki/Solder#Flux-core_solder (http://en.wikipedia.org/wiki/Solder#Flux-core_solder)
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OK, I'm using this topic for my question :P
Got my new soldering station yesterday, and finally asking for some basis questions ( :oops:)
1.How do you proceed with this? :arrow:
(https://www.dragonslairfans.com/forforum2/soldering1.jpg)
... I mean, do you clean 'the head?' on it between each soldering (or after a couple of..), when it's still on temperature? Or do you clean the 'head' on this 'white thing' (what is the English word?) when the soldering station is cold, after the job?
2. Does this 'kind' of heavy paper is also a cleaning part? :arrow:
(https://www.dragonslairfans.com/forforum2/soldering2.jpg)
:oops:
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... I mean, do you clean 'the head?' on it between each soldering (or after a couple of..), when it's still on temperature? Or do you clean the 'head' on this 'white thing' (what is the English word?) when the soldering station is cold, after the job?
2. Does this 'kind' of heavy paper is also a cleaning part? :arrow:
(https://www.dragonslairfans.com/forforum2/soldering2.jpg)
:oops:
The soldering iron head needs to be cleaned while working between one soldering and another. That "heavy paper" has to be a sponge. You need to add water to it so it will inflate and be ready to clean the iron.
Matteo
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Many thanks Matteo :-*
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And, even better if you can, get dry solder tip cleaner. It works just as well and doesn't reduce the tip's temperature each time because of the water.
I love this stuff.
(http://blog.makezine.com/upload/2009/07/toolbox_soldering_tools_part_2/dry_tip_cleaner_main.jpg)
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I always "flick" the excess solder off. Use a quick movement with your wrist and aim on a surface that can't be hart by hot solder (like a carton box or something).
Note that this is for advanced solderers only !
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I would say go hotter. 450 degrees (max on my solder station) is great for thick capacitor legs. And higher temperatures are less damaging then lower ones, as the time to heat can be kept much shorter.
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Somethings i learnd at school are. Alwees stab the sponge like you would do whit a sword. Dont wipe but stab. Also never set your iron to hot it wil burn the liquid thad helps the tin flow.
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ok, back on this since i'm still struggling: how long does it take for an old solder joint to get "flowing" when being touched with the soldering iron? i've tried temepratures from 350 to 400 degress, but nothing happens at all. i really think my soldering station isn't capable of producing enough heat anymore ...
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Hey you should have asked when I was around (didn't I actually show you ? I forgot).
First step is to ALWAYS tin the tip of your soldering iron with some new solder, so that it covers the tip and looks shiny. If you can't get the tip shiny anymore, your tip is very likely worn out.
The thing is with old solderings is that they do not have any "flowing" fluids in them anymore. This results in the fact that the old solderings won't start becoming fluid, no matter how high the temperature you apply.
So, to start running old solderings, you will need to add a little NEW solder. So put the iron on the old soldering, and then add a little new solder until it becomes fluid, then remove the new solder. Now you can suck it up. Recently I've switched from using a hand-pump tin sucker to solder-wick, it works MUCH better and cleaner IMHO.
As I mentioned before, get LEADED solder when you still can, it is a hell lot better to handle compared to the current unleaded stuff.
Yes, lead is bad for your health and the environment so don't inhale the fumes, but since we're not soldering 8 hours per day there is extremely little risk.
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Yes, lead is bad for your health and the environment so don't inhale the fumes, but since we're not soldering 8 hours per day there is extremely little risk.
Or make an extractor. That's what I did.
http://blog.makezine.com/archive/2008/11/nocost_fume_extractor.html
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So, to start running old solderings, you will need to add a little NEW solder. So put the iron on the old soldering, and then add a little new solder until it becomes fluid, then remove the new solder.
so basically i put the tip of the soldering iron on the old solderings, hold the soldering wire to the tip of the solderingh wire until it flows, wait until the entire "mount fuji" becomes fluid and then suck it up? i've tried this, but still nothing happens :(
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and if it still does not flow....
(http://farm4.static.flickr.com/3628/3355896838_5f010b7bd0.jpg)
kidding ofcourse :D
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and if it still does not flow....
thx etienne, that worked ... ;)
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I dont know the surrounding area, but if there are not too much parts in the neighbourhood,and its really a mountain of tin, you can try something with a little more kick ...
(http://www.gloeidraad.nl/radioforum/images/uploaded/200907142227394a5cea3b00df9.jpg)
just add new solder like mentioned before, or flux it like hell
it must come loose !
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i'm slowly starting to get the hang of it, but it is slow work indeed - at that rate my cap kit will be done by christmas :P. one joint refused to "melt" at all :evil: PLUS the solder-wick somehow doesn't do it for me, can't get it to "suck up" the old solder properly.
another question: once i've removed an old cap, do you somehow clean the area where the solder was with something like a fiberglass brush to get all the residues off?
and one more: i've found something called "kolophonium" in my soldering box and while i've looked up on the internet what that stuff is, i still don't quite know when to use it?
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Sounds to me your soldering iron is not producing enough heat OR the tip has worn out.
Does NEW solder actually melt right away when you touch it ? If not, it's not hot enough.
Get a good tool, you're going to be annoyed like hell for the rest of the time (and also probably make very unreliable solderings....)
Cleaning up residue is a good idea but not with a glass fiber pen (you will scratch away the protective plastic layer at some spots). Use some kitchen-towel and 99% alcohol (get it at the chemists). Maybe a toothbrush or another small brush.
O and Wikipedia is your friend:
http://de.wikipedia.org/wiki/Kolophonium
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Sounds to me your soldering iron is not producing enough heat OR the tip has worn out.
Does NEW solder actually melt right away when you touch it ? If not, it's not hot enough.
that's what i've been thinking as well. it DOES melt the solder, but not at the very tip of the iron (i'm using a very thin tip). plus sometimes the solder in the iron "hardens" while i'm trying to apply it to the new capacitor making the soldering iron stuck at the joint for a few milliseconds (know what i mean?). guess i should be looking for a new soldering station, unfortunately the one on rs online was only on offer in holland :(
O and Wikipedia is your friend:
http://de.wikipedia.org/wiki/Kolophonium
i had already read that, but i still don't understand when and how to use that stuff? do i apply it on top of a new joint i've made?
one more thing: the "mount fuji thing" doesn't work like it should for me, most of my solderings don't look extremely clean and mountainous. i'm trying to do it as i've seen it in some of the videos: put the soldering iron on one side of the capacitors leg and holding the soldering wick to the other side should make the solder melt and flow, but nothing happens at all. and when i apply the solder to the iron itself (which i was told is not the way to do it, sometimes it doesn't stick to the capacitors leg at all). man, this is more complicated than i had thought it was going to be. however, probably all due to my soldering iron not being able to hold / produce the temperature needed. guess i'll have to put my stuff away for a while and look out for a new station ...
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the tip does not warm up good as i understand you correctly
many times there is a screw that fixes the tip to the tool
unscrew, take out the tip, take a grinder, or sandpaper and clean the tip, or install a new tip
if its really dirty and burned use a file (Datei in german)
(http://www.vvcequipment.be/data/vijlen.jpg)
make sure that the screw is as tight as possible after you reinstall the tip, thats essential for heat conductivity
test with new solder on the tip
it should melt like crazy, if not buy a new station
http://www.youtube.com/watch?v=krxTfZCFptk (http://www.youtube.com/watch?v=krxTfZCFptk)
maybe Andre can forward the one that was in offer at RS online
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Trouble is that it was only on offer for a day IIRC.
I think filing maybe a bad idea for SOME tips, but I don't know what Ully's using.
Ully, EVERYTHING you mention points exactly to too little heat. The solder should do the work "by itself" If it's hot enough it will flow, if it's hot enough it will form a nice "mount Fuji" too. I bet your solderings are not shiny looking either.
One more thing: solder wick is this:
(http://www.girr.org/girr/tips/tips6/tool_tips/solder_wick.jpg)
Sounds you're confusing it with solder (tin):
(http://www.girr.org/girr/tips/tips6/tool_tips/sn63.jpg)
The wick is used to get old solder out of soldering holes.
Forget about that stuff you found in your soldering toolbox. You shouldn't need it with soldering electronics.
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nope, i meant WICK yesterday - doesn't suck up the older solder well. guess it's time for a new soldering station >:(
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Get a new soldering station and your worries will be over.
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Get a new soldering station and your worries will be over.
if only i knew which one to buy ...
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Farnell have a whole bunch of them.
This one (http://de.farnell.com/duratool/1498366-5090726-1467280/kit-soldering-st-draht-cleaner/dp/1737236) is the cheapest.
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that looks nice, its digital, it comes with sponge, and with brass tip cleaner, so it looks like a nice set for not too much money
personally i preffer weller, but this should be better than your old one ;)
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:shock:
http://www.youtube.com/watch?v=wUyetZ5RtPs&NR=1
:spaceace:
That's another way to do it!
Another good video: http://store.curiousinventor.com/guides/Surface_Mount_Soldering/101
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Just stumbled upon the videos from PACE
Nice 80s videos ! ;D
http://www.youtube.com/watch?v=vIT4ra6Mo0s&list=PL926EC0F1F93C1837
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Just stumbled upon the videos from PACE
Nice 80s videos ! ;D
http://www.youtube.com/watch?v=vIT4ra6Mo0s&list=PL926EC0F1F93C1837
Nice :-* Thanks for the link :spaceace:
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Yep nice movies. Judging by the devices shown in the film (this is filmed, not videotaped, pretty cool IMHO), cloths, hair-styles and general style of the film I'd say this is 70's stuff....
[EDIT] Woooops, there's a copyright screen saying 1980. O well....really "on the edge" both ways ;)
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I see i only linked to theyre "basic soldering lessons" but there is another playlist of them that is called "Rework & Repair Lessons"
Which are more interesting (to me at least)
especially episode 6 "Damage & Repair"
They fix a edge connector and traces there like we use to see them in arcade boards..
those lessons are from 1982, very nice also, and exactly the era of the boards we use ::)
http://www.youtube.com/playlist?list=PL958FF32927823D12