Solder technique: Over or Under? - Page 1
Forum section: electronics / beginners

author: MacMeter
author_rank: Frequent Contributor
timestamp: April 20, 2017, 11:03:27 pm
content: While I have yet to delve into actual small component electronics soldering, I have watched and enjoyed many of the videos here as well as linked YouTube videos. The closest I've done are LED ribbon pad soldering. I tend to have to do more larger wire joining, and have watched a few videos on that.So to the question for the experts here, this video asks and answers the question if "under" positioning of the iron is actually the best technique. Almost all of what I've read and seen suggests that is the best technique, but this video tries to prove the opposite. Perhaps this is only pertinent to the larger wire joining example in the video, as opposed to much smaller electronics type soldering, but I am curious as to the opinions of experienced folks here, the video is NOT long, so if you have a few minutes, check it out. THANKS!

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: April 20, 2017, 11:23:55 pm
content: What's "sodering" ? From below he's doing it wrong has to begin adding the tin to the iron until the wire begins to suck it, of course not on top of the cold wire, not until it's hot enough.

author: basinstreetdesign
author_rank: Frequent Contributor
timestamp: April 20, 2017, 11:38:18 pm
content: Just do it! above, below, it doesn't matter. Just do what works for you. All I know is that you need to get a good heat bridge between the tip and the workpiece to make the solder melt well into the joint. IMHO you have better things to do with your time than this. You will learn best along the way while building.

author: Audioguru
author_rank: Super Contributor
timestamp: April 21, 2017, 12:19:54 am
content: You need to drip the "soder" from way up high!

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: April 21, 2017, 01:47:55 am
content: Start with flux... I use the paste... just rub a little on the wires with your fingers, or dip the ends of the wire in the paste before you join them.Then I start with the iron below, solder on top, bit frequently end with the iron on top to smear the solder around up there as well. I don't think it matters so much so long as you heat things, apply solder, remove solder, remove heat. Most importantly keep the joint absolutely still until it cools (a few seconds or less unless the thing being soldered has a very large thermal mass).And just keep doing it until you find a way that works for you.

author: xrunner
author_rank: Super Contributor
timestamp: April 21, 2017, 01:49:54 am
content: Over?Under?I put mine on the side.

author: Shock
author_rank: Super Contributor
timestamp: April 21, 2017, 02:48:54 am
content: Towards the end of the video he showed his bias, he received a large burn 20 years ago from putting his hand under, his hands were about as steady as a drunken rabbi when he tried it.He solders from the bottom, applies solder to the top. Solders from the top, applies solder to the top so no wonder it was faster. Case closed.

author: Luminax
author_rank: Regular Contributor
timestamp: April 21, 2017, 04:27:19 am
content: "I shall solder from whichever direction I damn well pleased!"Taken from some possibly movie in some possible time in some possible universe

author: Brumby
author_rank: Unknown
timestamp: April 21, 2017, 05:28:11 am
content: I never knew this was an issue ...To me, soldering correctly involves producing a good, strong connection without damaging the items getting soldered, any surrounding material or injuring to persons ... and ... doing so quickly and with minimal wastage is preferred.Never thought there was a question ofwhich way is up.

author: Brumby
author_rank: Unknown
timestamp: April 21, 2017, 05:30:05 am
content: I'd like to see anyone do hand soldering of SMD from underneath.....

author: Luminax
author_rank: Regular Contributor
timestamp: April 21, 2017, 06:30:39 am
content: Quote from: Brumby on April 21, 2017, 05:30:05 amThat's easy! flip the board around and *sounds of components faling* crap....

author: Zero999
author_rank: Super Contributor
timestamp: April 21, 2017, 12:16:02 pm
content: Quote from: GeorgeOfTheJungle on April 20, 2017, 11:23:55 pmIn US English the "l" in soldering is silent.

author: Rerouter
author_rank: Super Contributor
timestamp: April 21, 2017, 12:26:55 pm
content: For me, it comes down to what i am intending, if i want excess solder in the joint, say its a very large wire that i'm thermally struggling with, I'll feed from the top, excess will build up, and then i'll heat from the bottom and it will knit and distribute on its way down,Add from top leads to excess,Heating from bottom can lead to a very lean joint,heating from the side is the ideal, but harder to manage with thin wires,There all just small tricks, and it comes down to what your trying to do, gravity is both your friend and foe, when its molten its both tugged to the heat source and tugged down by gravity, by varying your position you can change the amount of solder that can be bonded to the wire in a reliable joint.

author: daveyk
author_rank: Frequent Contributor
timestamp: April 21, 2017, 01:31:58 pm
content: This reminds me of Archie Bunker and Meathead arguing on if it's better to put on a sock and then a shoe or put on both socks and then the shoes in case of a fire - lolI solder on both sides!Sent from my iPhone using Tapatalk

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: April 21, 2017, 01:48:03 pm
content: Quote from: Hero999 on April 21, 2017, 12:16:02 pmAll over the USA?

author: daveyk
author_rank: Frequent Contributor
timestamp: April 21, 2017, 02:15:33 pm
content: Quote from: GeorgeOfTheJungle on April 21, 2017, 01:48:03 pmI don't understand that. I pronounce it "sod"-"er"-"ing".Sent from my iPhone using Tapatalk

author: tooki
author_rank: Super Contributor
timestamp: April 21, 2017, 03:55:24 pm
content: Quote from: GeorgeOfTheJungle on April 21, 2017, 01:48:03 pmYes. It's not some weird regionalism, it's absolutely standard pronunciation in USA (and Canada, I believe). You'll always find some Americans who pronounce the L because they learned the written word before ever hearing it pronounced.

author: Luminax
author_rank: Regular Contributor
timestamp: April 21, 2017, 04:01:10 pm
content: I just can't resist commenting on this video...The title should've been "Soldering using the wrong method is wrong"If I were one of the great solderer I would head him off at the pass"YOU SHALL NOT SOLDER!"

author: rrinker
author_rank: Super Contributor
timestamp: April 21, 2017, 05:08:44 pm
content: What is your quest?What is your favorite solder?What is the capitol of Assyria?What is your quest?What is your favorite solder?What is the color code of a 1K resistor?1% or 10%?I don't know that.....

author: boffin
author_rank: Unknown
timestamp: April 21, 2017, 05:19:57 pm
content: Quote from: rrinker on April 21, 2017, 05:08:44 pmWhat's the air-speed velocity of an unladen swallow?

author: Monkeh
author_rank: Super Contributor
timestamp: April 21, 2017, 05:22:05 pm
content: Quote from: boffin on April 21, 2017, 05:19:57 pmAfrican or European swallow?

author: Zero999
author_rank: Super Contributor
timestamp: April 21, 2017, 06:13:07 pm
content: All the discussion about radiation and convection is irrelevant because conduction is the main vector for transferring heat to the workpiece. Air has a very low heat capacity so doesn't do much and metal is reflective so looses very little heat due to radiation.I also suspect his soldering iron was a little too hot, going by how quickly the solder was oxidising and the flux evaporating.As others have said, do what works best for you. I solder from the side most of the time. I can also hold both wires side by side with one hand so I don't need to twist them together or use a vice.

author: Gregg
author_rank: Super Contributor
timestamp: April 21, 2017, 08:09:34 pm
content: Soldering is more skill than it is science; you are free to create your masterpieces (or pieces of s___ or whatever) in any way that works best for you and the situation at hand.Another analogy is that it is like learning to ride a bicycle in that after enough practice you won’t have to think about the exact method every second you are soldering. There are no absolute correct methods, plenty of poor methods and almost infinitely variable parameters.One parameter that hasn’t been mentioned so far in this thread is the importance of not moving the soldered joint as the solder is solidifying.

author: james_s
author_rank: Super Contributor
timestamp: April 21, 2017, 08:48:20 pm
content: Quote from: tooki on April 21, 2017, 03:55:24 pmI've heard some Canadians pronounce the L, sounds weird to me but that's only because I'd only ever heard it pronounced with the silent L.

author: John B
author_rank: Frequent Contributor
timestamp: April 21, 2017, 09:03:08 pm
content: Once I start joining thicker wires, I prefer to use a hydraulic crimping tool over soldering. Thick wire draws heat away from the soldering area, and the solder wicks down the wire making an large inflexible area. Maybe not worth worrying too much inside a small piece of electronics equipment, but its my default method now in automotive applications where the wiring is out in the open and needs some flex.

author: tautech
author_rank: Super Contributor
timestamp: April 21, 2017, 09:44:16 pm
content: Quote from: MacMeter on April 20, 2017, 11:03:27 pmWhen you do you will in time develop your own style........eg. for SMD as you will never have enough handswhile holding a component on the pads touch the pad with the iron tip close to the component and allow the solder to wick into the joint and create the fillet. Rinse and repeat on the other pad/s and maybe top up the fillet from above/over to make a larger/stronger fillet. For the size SMD that is easy to solder (0603 +) the common mistake is to use too smaller tip that won't hold enough solder to make even a small fillet to hold the component in place until one hand is free from tweezers and can hold the solder reel.As SMD components are plated a pre-tin of the pad is usually enough to have enough solder there when touched again from above/over with the component in place will form a good enough joint to tack it for the final soldering.Others will have their own style and it's good to share what works for each of us as we can all pick up little tips.

author: Audioguru
author_rank: Super Contributor
timestamp: April 21, 2017, 09:51:46 pm
content: In Canada I pronounce it as saw...der. In England they pronounce it as so...daw. I say water and they say wotaw.

author: neko efecktz
author_rank: Regular Contributor
timestamp: April 21, 2017, 10:10:44 pm
content: Tomatoes - tomartoesPotatoes - potartoesLet's call the whole thing off.WE SPIKA DA INGLISH GOOD NO?

author: Zero999
author_rank: Super Contributor
timestamp: April 21, 2017, 10:44:29 pm
content: Quote from: Audioguru on April 21, 2017, 09:51:46 pmI've never heard anyone in England not pronounce the "L" sound in solder, perhaps you missed it? We all say sol daw.

author: Brumby
author_rank: Unknown
timestamp: April 22, 2017, 02:04:05 am
content: I've only heard people refer to "sodding" from North America.In Australia, the material is referred to as "sol-dah", "sol-dar" or occasionally "sol-der". No sodding down here.

author: Luminax
author_rank: Regular Contributor
timestamp: April 22, 2017, 04:44:03 pm
content: we pronounce it 'soul-der' hereBut anyway, the point is not that what is the correct method (because there's none, correct technique maybe...) but the fact that he's pushing his ideology of this 'correct method' and says that the other method is wrong, and boy that sure triggers me!... I've been watching too many of those social thingamabob video on youtube, somebody shoot me...

author: Brumby
author_rank: Unknown
timestamp: April 23, 2017, 12:27:08 am
content: If we give you a little more time, you'll be prepared to shoot yourself - or the computer. Saves any of us from having to face the consequences of a mercy killing.Go fishing - or plant a tree.Better still - go find an interesting piece of test gear and take it apart!

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 23, 2017, 01:28:33 am
content: As many have said, you can get a good solder joint with many techniques.I believe that back when manufacturing involved making lots of hand soldered joints the manufacturers found that cold and unfilled solder joints occurred more frequently when solder was added on the same side of the joint as the iron. Makes sense, the far side of the joint will be cooler, and possibly below soldering temperature. You can watch this happening yourself if you solder large wires with a low power iron. This observation then informed the training on how to solder and has been passed down through the years. But it has nothing to do with top or bottom.

author: daveyk
author_rank: Frequent Contributor
timestamp: April 23, 2017, 02:07:17 pm
content: Quote from: neko efecktz on April 21, 2017, 10:10:44 pmYuns should come to central Pennsylvania; we'll fix that opinion."Tar" has three meanings:The radio broadcasts from a "tar"The "tar" on your car is flatYou need more "tar" on your ruf to keep it from leaking.Fire:Start a "far" and burn that rubbage.Harrisburg is a "far" ways away.I could go on...Sent from my iPhone using Tapatalk

author: mfratus2001
author_rank: Contributor
timestamp: April 23, 2017, 04:30:25 pm
content: He is using a soldering GUN, which is only appropriate for large wires and large objects. In general, though, the same principles apply. He gets it WAY too hot. See the big cloud of flux/lead vapor? Not good.The first and foremost goal is to transfer heat from the tip to the wire. "From below" isn't much better than using a candle or match to heat the wire. "From above" is lame also because he is not using any pressure between the iron and the wire. Instead, he drips solder onto the wire from the hot iron, and creates a bridge of solder to transfer the heat to it.Best practice would be to use pressure between the iron and wire, apply solder between the iron and wire, and let it flow, not "paint" it onto the wire. Always use rosin core solder, or either liquid or paste rosin.Same technique is used with an iron and even with SMD devices, except that you tin the iron and control the heat better. Don't let it get so hot that it evaporates the flux (that big cloud when the solder touches the iron) and "cooks" the solder (solder gets rough-looking and creates peaks and strings), and most importantly, burn up your PCB and device!Solder should NEVER be "painted" on. It should FLOW onto the joint.Lead-free solder is special and takes special techniques and even special flux.

author: rrinker
author_rank: Super Contributor
timestamp: April 23, 2017, 05:28:59 pm
content: Quote from: daveyk on April 23, 2017, 02:07:17 pmThrow the horse over the fence some hay and don't forget to outten the light when you're done.

author: Shock
author_rank: Super Contributor
timestamp: April 23, 2017, 05:50:41 pm
content: Quote from: mfratus2001 on April 23, 2017, 04:30:25 pmLead boiling point 1749 °C, ?3180 °F.

author: mfratus2001
author_rank: Contributor
timestamp: April 23, 2017, 06:11:58 pm
content: Solder does not have to boil for the lead to evaporate, same as any liquid. It just evaporates faster, the hotter it gets.OK, it could also be that the metal oxidizes, but I see loss of solder volume on a really hot tip, and the solder is not much good after that, so it could be both. Just stay in the right temperature range and you won't have much trouble.http://www.kester.com/knowledge-base/faq#46341-tip-temperatures-what-is-the-recommended-soldering-iron-tip-temperature

author: daveyk
author_rank: Frequent Contributor
timestamp: April 23, 2017, 06:40:48 pm
content: Quote from: rrinker on April 23, 2017, 05:28:59 pm<smile>Sent from my iPhone using Tapatalk

author: tooki
author_rank: Super Contributor
timestamp: April 24, 2017, 08:10:31 am
content: Quote from: mfratus2001 on April 23, 2017, 04:30:25 pmSays who? The professional tutorials I've seen very much say that it should be "painted" on, literally using that exact word. I think perhaps you're using the term "painted" to mean "applied to an uncooperative surface", which isn't what everyone else means.

author: mfratus2001
author_rank: Contributor
timestamp: April 25, 2017, 09:24:09 pm
content: I have been working in electronics as an occupation for decades. I worked as an assembler, in test-and-repair, in engineering positions, and in design positions. I have learned from the best and can produce NASA- and MIL-Spec-level work. So, as one who was paid to correct the mistakes and poor workmanship of others, and be the one to say that a product is ready to ship... I kinda think I'm qualified to say what is a proper soldering practice and what is not.And, I actually have taken (and passed) a few certificate-level classes on soldering. I was just sharing my knowledge and experience with people.You can download a free copy of the Radio Amateur's Handbook from the ARRL athttps://archive.org/details/RadioAmateurHandbook1976and read the section on soldering if you want. This handbook is great for hobbyists and professionals alike. It covers the practical aspects. It is about 60MB but is a keeper.It would be interesting to see what videos you are talking about, but, alas, no links.

author: tooki
author_rank: Super Contributor
timestamp: April 25, 2017, 09:31:22 pm
content: One example that came to mind is the videos from PACE, which expressly talk about painting solder on.E.g.https://youtu.be/Mrhg5A1a1mU(skip to about 5:05)andhttps://youtu.be/AY5M-lGxvzo(skip to 2:00).

author: mfratus2001
author_rank: Contributor
timestamp: April 25, 2017, 09:54:05 pm
content: I see what you mean. I have seen people "paint" solder onto joints, and never make that metal-to-metal connection. In some of the repairs I do, I find wires through holes, and even wrapped around terminals, but because not enough heat was used to get the flux and then solder flowing, the wire never was actually soldered onto. You could just pull the wire right out.In professional soldering, you are not allowed to have voids and blow-holes, and the solder has to be bright and smooth.The final appearance of the joint is the judge as to whether you have the right technique or not. Good videos. Thanks.

author: tooki
author_rank: Super Contributor
timestamp: April 25, 2017, 10:26:25 pm
content: Absolutelty. As I said in my first comment, if by "painting" you meant forcing solder onto a non-receptive surface, then yeah, it's very bad. But I think that if the joint is done properly, as PACE's military-grade demos show, then wiping the solder wire across the joint to apply it is a valid technique.I know exactly what you mean with those bad joints.If you haven't seen all of PACE's videos, wait till you get to thereworkAdventures in Repair series! You're in for a treat (of corny acting awesomeness)!!https://youtu.be/hzZuryFmPo0

author: Brumby
author_rank: Unknown
timestamp: April 26, 2017, 02:55:18 am
content: Corny acting excluded, that was interesting.Never had to even contemplate such repair work - and you would certainly need to have the right tools on hand to make it easier and quicker to do a good job.Not sure how you would go with some of the boards around today, though. Those training board tracks seemed reeeeaaaalllly broad and widely spaced.

author: MacMeter
author_rank: Frequent Contributor
timestamp: April 26, 2017, 03:52:45 am
content: That's some CHEESY production value! But, I still want to watch the next episode.

author: BrianHG
author_rank: Super Contributor
timestamp: April 26, 2017, 04:26:09 am
content: I just watched all 3 at 2x speed... LOL...

author: tooki
author_rank: Super Contributor
timestamp: April 26, 2017, 09:39:40 am
content: Quote from: Brumby on April 26, 2017, 02:55:18 amEverything about PACE tells me that at least back then, their specialty was in military electronics (they were originally based in Silver Spring, Maryland [a place I once lived!] — defense is Maryland's biggest industry). As such, cost is nearly no object, and I expect that the boards needing repair are necessarily older and conservatively designed.That said, no doubt they have newer training materials that aren't on the web, and handle such rework on modern boards. ::shudder::

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 26, 2017, 03:33:05 pm
content: It is hard to imagine where that level of effort is a better choice than doing a new board. Until you realize they aren't working on their own product.

author: tooki
author_rank: Super Contributor
timestamp: April 26, 2017, 05:21:26 pm
content: Quote from: CatalinaWOW on April 26, 2017, 03:33:05 pmNot only that, but possibly on a product that hasn't been made in years.Take a look at this company, whose specialty is to continue manufacturing obsolete semiconductors for the military (by buying the tooling, specs, processes, intellectual property, etc — and the contracts — from the company that's abandoning the product):http://www.lansdale.comThis is their slogan:

author: CatalinaWOW
author_rank: Super Contributor
timestamp: April 26, 2017, 08:56:15 pm
content: Quote from: tooki on April 26, 2017, 05:21:26 pmI get all that, but with today's design tools in quite a few cases it would be easier, faster and result in a better repair to reverse engineer the PWB, have a new PWB fabbed and then re-install the old components. Or new old stock, or whatever.Unless.....