Advice for a soldering noob?

[giftiger_wunsch]

That's a lot of posts, thanks for all the advice. I'll take a look at the reel of solder and check for any indication on type, etc., but I don't think there are any markings. The solder is very dull on the exterior so it may well be that it needs cleaning.

As for the copper on the board... it's a board from a VCR about 10 years old, which I took apart, left out in the rain for about 3 weeks before realising there was still plenty I could salvage from it, and then I inexpertly desoldered about 40% of the components on the board, and in many cases lifted and damaged the copper tracks. I doubt there's much I can do to improve the situation there, next time I'll use a different board for practice

Thanks for the suggestion for a solder station bountyhunter, but this is the second iron I've bought in quick succession so I'll probably stick with this until I have some cash going spare / decide I desperately need a thermostatically regulated iron.

 

[mneary]

First pic: The solder (iron?) was too cool and the solder was soupy not liquid. That's why there are little fingers leading away from the center mass.

Second picture: Flux is gone. You can probably fix with a drop of flux and a quick touch of a solder tip (with half a drop of solder on it.) Before fixing, you might need to cool the iron a little. If the iron wasn't too hot, it just means you work more quickly with more flux.

Third picture: Good, maybe 25% more solder than necessary. Doesn't need fixing.

Fourth picture: Good, apparently added flux and solder to keep it wet as suggested. Unfortunately it peeled back the wire insulation. Sometimes I use stainless tweezers (like we use for smt parts) to heat sink tiny wires. Problem is, where's my third hand?

Most importantly (to me) is the size. I use 0.015" solder almost exclusively. For really gross work (0.40" and fatter) I keep some 0.032" around.

A needle dropper with appropriate flux is essential for me to re-do as many connections as I do. I use Solder Wick to pull my excess solder away; for me, suckers are mostly for gross work (0.40" and fatter).

 

[giftiger_wunsch]

As I thought, the solder I'm using doesn't have any markings on the reel which would indicate its size or composition, but it appears to be 1mm (~0.04") in diameter. Perhaps the solder being too thick is part of my problem. Regarding the comments that I've used too much solder, I've found mainly that when I touch the solder to the hot joint + iron rapidly, I usually get almost nothing on the first flick across, and then a flood on the second flick. But perhaps I'm simply not removing the solder quickly enough; I usually remove it as soon as I see the solder start to flow onto the joint.

By the way, I'm sure this is absolutely no help at all but I thought I'd mention that the solder I'm using has a very different smell to the solder already on the VCR board. The one I'm using has a much stronger smell, rather more acrid. Just in case that's any vague use in identifying what type of solder it is.

 

[giftiger_wunsch]

Had another try just now, and took a couple more pictures. I'm not sure if the brown discolouration of the joints is flux or dirt.

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[bountyhunter]

Had another try just now, and took a couple more pictures. I'm not sure if the brown discolouration of the joints is flux or dirt.

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Use a bit of acetone spritzed on a Q tip to scrub the flux off and see what you've got. Use auto carburetor cleaner or non-chlorinated brake cleaner spray for this. It will stink up the room so your spousal unit may not appreciate it....

 

[audioguru]

Most NOOBs drip the solder on a joint from much too high. When the molten solder drips from 1m or more above the solder joint then it is much too cold when it lands on the joint. Hee, hee.

 

[mneary]

Doesn't matter if the brown is flux or dirt. It's a Good Thing to have flux left over as long as the connection is properly fused.

I use IPA (Isopropyl) to clean my connections; acetone seems like overkill. But IPA does contain water so it does need to be dried thoroughly.

Solder from the factory will smell different than yours; there are many different types of flux. The flux used in the factory is designed to flow on top of a fountain of solder as the bottom of the board passes by.

Your soldering is improving rapidly. It's better than I think I could do with 0.040" solder; I haven't tried lately.

 

[Mr RB]

Get more heat in there, either leave the tip on the joint a little longer or turn the temp setting up.

If there is old solder on the joint (ie the orig VCR solder) it won't solder very well, you may have to apply clean solder a few times and keep removing the excess from the tip.

I prefer 1mm solder, even for tiny SMD stuff. 0.8 needs unrolling too often.

 

[giftiger_wunsch]

I think I'm using an appropriate temperature setting, so I'll try to make sure I have firm contact between the tip and the pad/lead over as large a surface area as possible and leave it there for longer if necessary, though I've heard that it should only take ~1 second.

I had the temperature higher before when I was desoldering as I had difficulty melting the solder on the VCR board at lower temperatures, but when I got a bit more used to maximising the contact between the tip and the joint that helped a lot. I found that at the higher temperature the solder was heated so quickly that it would spit, occasionally a fair distance. Corrected the issue after a small piece of molten solder burned my finger

Though I've also found that even at a high setting and using as much of the side of the tip as possible to increase the surface area of contact, I've had difficulty desoldering the heatsinks and transformer. Is there any particular procedure for desoldering devices which can absorb so much heat, or is it simply a matter of holding the iron there until the solder eventually melts? Other than this slight snag I'm reasonably confident with my ability to desolder components now, so I'm mainly focusing on my actual soldering.

 

[Mr RB]

1 second is nowhere near long enough. Maybe 3 seconds on an old solder joint, the flux needs TIME to clean the metals especially the steel component lead. You need to get it wet, get some solder on, remove the dead solder and filth (tap the tip to flick it off in your tray) and once more with fresh solder for the final joint.

With a new clean PCB and component leg, especially a small pad size, 1 second may be enough but even then i'd say 1.5 seconds and two quick solder dabs.

For large joints like the heatsink tabs I get it wet then apply LOTS of excess solder, then just hold the side of the tip on it and wait. The increased thermal mass of that big melted solder blob and its increased contact area with both the tip and the PCB helps carry the heat into the PCB copper and the heatsink tab much quicker.

For removing parts like TO-220 (and all 3 leg transistors, even most 2 leg caps etc) I apply a heap of solder to all legs at once (again the thermal mass) and jam the side of the tip against all the legs at once. Generally you can remove a transistor in about 2 seconds this way and it's so quick you wont damage the PCB so it's not as butcherous as it sounds. I also like to run my iron tip a little hot at 325'C and get in and out quicker but it does require a bit more cleaning of the tip.

When we had TV repair shops I used to get the apprentices practicing for a few weeks desoldering parts from TV and VCR PCBs for at least a couple hours a day. When they can pull a cap or TO-220 in a couple of seconds, and a DIP 16 with a sucker in under a minute then they can solder pretty well.

 

[AllVol]

I'm reasonably confident with my ability to desolder components now, so I'm mainly focusing on my actual soldering.

If you do not already have one, get a good magnifying lens or, better yet, an adjustable light with magnifying lens. Seeing well makes soldering easier, I find.

 

[mneary]

You mention splashing the solder... you are using safety glasses, correct? I have safety reading glasses, which makes it easy for me to remember.

I've scraped flux and solder droplets off the lenses, I'm sure that was easier than cleaning a cornea.

 

[bountyhunter]

I've scraped flux and solder droplets off the lenses, I'm sure that was easier than cleaning a cornea.

When hot solder hits the cornea, it cools enough to solidify and the next blink of the eye knocks it away leaving a white scarred area on the cornea. If you are REALLY lucky, the cornea heals up reasonably well (enough to see through) but you have to keep it covered for about a week and pray a lot.

You really don't want to go through that.

 

[mneary]

I prefer glasses.

 

[giftiger_wunsch]

... perhaps I should acquire safety glasses. Though so far it's never spat high enough to get anywhere near my eyes and at lower temperatures it doesn't usually spit at all.

 

[bountyhunter]

... perhaps I should acquire safety glasses. Though so far it's never spat high enough to get anywhere near my eyes and at lower temperatures it doesn't usually spit at all.

It isn't the spitting upwards as you solder that is so dangerous. 30 years back when I had it happen to me, I was holding a small piece of 12 gauge wire with needlenose pliers and was tinning it with my soldering iron, so it was covered in a layer of hot solder. The piece of wire slipped out of the pliers and fell straight down towards the workbench. When it hit the bench, the solder was sent up into my eye. I have no idea how exactly, but that's what happened. Probably a million to one shot to hit my eye, but it did.

Always protect the eyes. I shoot pistols every week and so I have the lenses of my glasses made from polycarbonate which is shatter resistant. On my shooting glasses right now, there is a "quarter moon" shaped chunk gouged out of the right lense, dead center on line with the middle of my cornea. I know exactly what put it there: a 9mm brass case which was ejected bounced off the wall and came back at me. The open mouth of the hot brass case hit the lense, gouging a piece out. God help me if that had hit my eye....

 

[PedroDaGr8]

Heck safety glasses are so cheap, it makes no sense NOT to use them. I have had my eyesight saved MANY times in the lab (chemist), where stuff would spatter, flame up, bounce, break, etc.

 

[giftiger_wunsch]

Heck safety glasses are so cheap, it makes no sense NOT to use them. I have had my eyesight saved MANY times in the lab (chemist), where stuff would spatter, flame up, bounce, break, etc.

I'm always one to be very careful with safety equipment working in labs, but I must admit the danger while soldering hadn't occured to me. I'll have to see if I can get some. In the meantime I have some simpsons UV protective "beer goggles" which will both protect my eyes from flying solder, and make me look epicly cool

Of course there are times when safety equipment in labs just doesn't cut it. I know someone I went to school with who leant over a bunsen burner he didn't realise was on, and burned a hole in the armpit of his labcoat . And then there's the very clever individual who was playing around with a pot of hexane fitted with a wick (which was lit, of course) who knocked it over and promptly spilt the flaming contents over his hand.

 

[giftiger_wunsch]

The open mouth of the hot brass case hit the lense, gouging a piece out. God help me if that had hit my eye....

Ouch As grateful as you'd have to be for the blink reflex in that situation, I don't think it'd be that much consolation while you were getting stitches in your eyelid I've only used a firearm 3 times, I was in the Air Training Corps when I was 13 . Low velocity single-shot rifle, and no spring mechanism so the casings either fell out when the bolt was drawn back or sometimes had to be removed by hand; fortunately no need for eye protection and no real risk of that happening.

I caught myself just now holding the iron above my hand while tinning a wire, and just as I was about to call myself an idiot and put it down, a drop of solder fell off the iron onto my hand. I think I deserved that one it's unpleasant even with a tiny drop of solder you have to look hard to be able to see, I don't want to experience a larger amount, or worse, getting hit in the eye