World's Worst Soldering!

Very few people are good at soldering. The defense companies require extensive training and certifications in order to touch any equipment that is customer category. Most engineers are adequate, at best. And that is the way it should be

There may be hope for you yet:

1. How many watts is your soldering iron? It looks like the mess made by too low power or too fine a tip. 75 watt seems about right.
2. Is the soldering iron temperature controlled? If yes, raise the temperature and work fast. Mine runs at 750F (400C) for 60/40 lead-tin. If no, go shopping and buy a decent adjustable temperature controlled soldering station. Get a fine tip for fine work, and a thicker tip for the big stuff (so that the tip doesn't go cold as soon as you touch the work).
3. Are those 3300uF 25V caps 85C caps or 105C? The photo looks like

85C. If so, they'll last about 6 months inside a hot oscilloscope.

1. Clean the enamel off the wires with sandpaper before you solder. Tin the wire ends before attaching to a lug or PCB rivet.

I've dragged some of the local hams into my palatial office and demonstrated how easy it is to solder properly with a decent soldering iron. They're usually amazed at how well THEY can solder using my equipment. That's when I discover that they're using something from Radio Shack or that came with their childhood wood burner kit. I just did a quick scan of what's available on eBay and noticed that they now have OLED display aftermarket temp controllers for HAKKO soldering irons. I'm tempted: Also, if you don't have a hot air SMD workstation, this might be a good time to get one because they often include an adjustable temperature controlled soldering iron.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Really bad.. Im suprised that the diods are still alive after that burn. Have to be a newly employed that did not get His/her 2hr education before doing the job

Den 2018-10-07 kl. 18:08, skrev Cursitor Doom:

50

ensive training and certifications in order to touch any equipment that is customer category. Most engineers are adequate, at best. And that is the way it should be

I think in my day I could solder "adquately" as you say. It was when I met people who do it 8 hours a day 5 days a week that I realized my soldering was very poor by comparison.

These days it is mostly done by machines and the quality depends on the tem perature profile and the design of the pads. Again, that's not my part of the job so I'm no expert, but I'm not sure many people responsible for the soldering are "experts" either. They get the job done though.

Rick C.

There is no shame in liquid solder flux. Think of it as liquid GOLD.

Link:

About $6 a bottle, which will probably go bad before you use it up.

Cursitor Doom

Cool

Now that is an interesting bridge rectifier.

Here a raspberry replacing a big chip:

That thing has been working all day now since Dec 2013 without a glitch. Nothing to worry about.

Even older, 1985 or so, still works:

Na, it is OK.

I sort of like soldering, but only 60/40, maybe it is the lead ...

:-)

have many boards like that....

Scroll down can you find the SMDs on the board?

that is some Giggle Hz stuff too. It is still working, in fact added some stuff.

Soldering is simple.

You need a good temperature controlled soldering iron, some solder wick, some 60/40, and there you go. I count to 14 at 320 C for it to flow ... around pins.

:-)

A good soldering station and good hand tools (eg. - strong needle nosed pliers, shard edge clippers) are indispensable for repairing equipment properly.

I spotted what looks like "10..." curling over the edge on the edge of one of the caps, so he is at least using 105C caps. The caps should be secured though.

Sandpaper may be too aggressive if a rough grit, that can introduce scratches to the copper leaking to the potential for breakage. I suggest using something more like wet/dry emery cloth of about 1000 grit - true, it is another sandpaper, but less likely to scratch.

The invented bridge rectifier was poorly made for the space allowed, and those bridge modules are readily available. If you need to make a bridge module wrap the leads at least one loop around the others for a mechanical junction prior to soldering. Then there less risk of a solder joint breaking and introducing random loose parts into your equipment...

This looks handy - so I've ordered a couple for the shop:

Nice to be able to check calibrations by comparison.

John :-#)#

Unfortunately not!

I have 15W, 25W, 40W and 80W irons. This atrocity was carried out with the 15W one which has a pointed tip for some reason.

You're very kind in attributing this train wreck of a repair to my having the wrong tools, Jeff. Sadly I don't believe it's the case. This kind of work requires a steady hand and a keen eye and I possess neither.

I followed the original spec as far as possible. The originals were

5500uF, 30VDC and 85C. I couldn't get the right capacitance within the space available so used 33's in parallel. The old 85C's lasted for decades so your 6 month assessment may be a bit pessimistic.

Yes, I did do that. I know what I *should* do but it doesn't help.

Can you imagine the carnage I'd leave behind attempting SMD stuff?? :-D

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I scrape magnet wire with an x-acto knife. That leaves a shiny surface that wets nicely. I think the professional wire strippers use rotating knives.

A serious high-power, controlled temp iron is basic to good soldering. I like my Metcal.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

John Larkin wrote

that burns the magnet wire insulation, and then you can just tin it. Scraping damages the wire. But watch out for the terrible possible toxic smell.

I have a brush that uses fiberglass. Cleans quickly, bends a bit to get the rounding needed, and doesn't run any risk of nicking the wire.

Something like this:

Also polishes edge connections, etc. a very useful tool.

For regular board work I like my Weller stations with the magnetic temp controlled tips, I mostly use the #7 medium or thin screwdriver tip.

John :-#)#

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Beldsol and some similar wires are meant to be thermally stripped.

Not #14!

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics

wrote in news:ppdl16$1gq8$ snipped-for-privacy@gioia.aioe.org:

60/40 is for plumbing.

The electronics industry settled on and proved to be the best 63/37 and for decades it was. This RoHS shit is the worst thing the world ever did. Metallic form lead is not dangerous to the environment.

If it were, there would be huge lead levels around all the damned police shooting ranges in the nation. There is not.

Eh. This was the soldering job in a commercially-sold SMPS bench power supply from an Amazon.com reseller, IIRC, this was how it looked when it left the mfgr, I took this photo immediately after opening the enclosure and pulling the PCB (it had stopped working! can you believe it)

I'm using 400 grit wet/dry sandpaper for removing enamel. No reason other than it seems to last longer than the finer grits and I have a fair number of sheets. For very thin magnet wire or litz wire, I use finer sandpaper. If I want to scrape off the insulation, I use a moderately dull edge kitchen knife that won't cut or gouge the copper wire. If I try to solder magnet wire that still has some coating on the wire and was not tinned, I get a black carbonized blobs, like in the photo.

I have one of those. It's a counterfeit clone and is not made by Hakko. This is what the real FG-100 looks like: Note the price. I haven't bothered to verify the calibration on mine, but it seems to indicate what I would expect.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Eek! I'd like to see some insulator other than air between the AC nodes of that bridge rectifier, it doesn't look like the gap is very much at all.

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This is pretty bad. The box doesn't work.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics

There's your problem. 15 watts is far too small for the heavy gauge wire you're using. The pointed tip is too small to retain enough heat to solder some of the larger parts in your photos. You also didn't bother to disclose whether you're using a temperature controlled soldering iron or a crappy wood burner. I'll guess(tm) a wood burner, probably with unplated rusted iron tips that can't be cleaned, wetted, or tinned.

If my guess(tm) is correct, you don't have a prayer making a decent solder connection even with a keen hand and a steady eye. The trick to soldering is to use decent equipment, a clean tinned tip, and the correct temperature. Use a hot tip set to the temperature for the type of solder you're using. Get the work hot quickly, solder quickly, and remove the iron as soon as possible. If you use a stone cold 15 watt iron, you'll end up lingering on the joint for far too long, which will dramatically increase the size of the heat affected zone, which will likely burn the PCB, vaporize the flux before it's needed, and possibly run some parts. By fast, I mean something like 1 second or less.

A friend of mine lived long enough to get Parkinsons Disease. Near the end, his hands shook bad enough that soldering was impossible. However, before that, they were steady enough to hold the iron, but not the work (wire and components). So, he build a fixture with an articulated battery terminal clamp to hold the joint together while he soldered it. For the soldering iron, he build something similar that only required that he leaned on the iron to push it into the connection. The process wasn't graceful, but it worked.

If you have vision problems, get a proper magnifier or microscope. My eyesight is becoming bad enough that I need to use a microscope for SMD work, and a magnifier for ordinary work. Good lighting also helps. My soldering would look as bad as yours if I didn't have these aids.

If you're not sure that decent soldering equipment will improve your miserable soldering, then borrow someone's decent equipment and try it for a day or three. If it's hopeless, look into the possibilities of using a soldering robot: (1:33)

I had problems finding can type electrolytics so I used axial leaded electrolytics as a substitute. They fit inside the old can, so I just ripped out the guts from the defective capacitor and crammed the axial caps inside. I used 85C caps which lasted about 6 months. I replace them with 105C caps and they've been running for about 2 years.

If you know it's not going to work, why bother doing it? You're not going to get a decent solder connection if it's covered with melted or burnt insulation, no matter how nice your tools or technique. A decent solder connection requires that ALL the parts of the puzzle are clean before you apply heat and solder. Do it.

It takes a bit of practice, but once you understand how it works, it's quite easy. Soldering SMD devices with solder paste is easy because the part self-aligns itself on the pads once the solder melts. There are plenty of videos on YouTube showing various ways to use a hot air SMT desoldering station. Instead of declaring defeat and surrendering before you start, watch a few and decide if you can handle it.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Haha, I actually saw a small pile of those on the shelf at the local (well, only) brick and mortar components retailer in the Boston area, on sale for $8 each in kit form.

I think I'll pick one up next time I don't think I've ever owned a capacitor substitution box before, or really needed one (it's easy to substitute capacitors in Spice) but might come in handy someday, and I mostly trust my own soldering. Maybe I'll splurge on some better quality through-hole caps for it than those ceramic disk....things