What Tips do I Need to Solder 8-12AWG wire and Small Electronics - Page 1
Forum section: electronics / beginners

author: yash101
author_rank: Contributor
timestamp: April 30, 2015, 04:41:24 am
content: Hello There,I'm new here, so Greetings. I'm probably getting a bit redundant nowI'm in a high school robotics team and need to solder thick and thin wires all the time. I'm still a N00b at soldering.My team has a Weller station as well as a RadioShack station. Which one do you guys suggest is better quality to invest in?I need tips for soldering thick wires (8-12 Gauge) as well as thin signal wire (20-22 Gauge) wire. I also need a tip to perform the typical thru-hole operations.

author: cdev
author_rank: Super Contributor
timestamp: April 30, 2015, 05:06:57 am
content: get one of those old, huge soldering guns for the big wires, and keep them away from the actual electronics, they are for when you need to solder something like copper that has really good thermal conductivity.. otherwise you will never get the solder properly melted...

author: Rick Law
author_rank: Super Contributor
timestamp: April 30, 2015, 05:23:03 am
content: If you are soldering it to a connector, you should try propane torch.I was helping out with my daughter's high school Robotics team. I did a lot (dozen) of AWG 6 (could be AWG 4) to battery connector (to SLA) with propane torch and it works very well. Initially, I was leaning towards a strong soldering gun also. I saw another guy did it with torch and I was force to try since we don't have high power solder gun at hand. But having done it with propane torch, now torch is my first choice for 10AWG or thicker (if it can withstand being that close to flame).

author: rx8pilot
author_rank: Super Contributor
timestamp: April 30, 2015, 05:27:34 am
content: Quote from: cdev on April 30, 2015, 05:06:57 amI had one of those 100 watt guns from Radio Shack decades ago. It was fantastic for big wires but destroys the smaller stuff.

author: edpalmer42
author_rank: Super Contributor
timestamp: April 30, 2015, 07:11:17 am
content: I've got a precision torch that fits on a regular propane bottle. Lots of heat, concentrated in a small area. I soldered #10 stranded wire to a connector without melting the wire's insulation less than 10mm away.Ed

author: yash101
author_rank: Contributor
timestamp: May 01, 2015, 01:02:32 am
content: I don't think a torch would be an ideal idea.I spoke with our school's digital electronics instructor and he told me that a propane torch would melt the copper itself!This is all for FRC (FIRST Robotics Competition) soldering -- low-AWG wire for passing up to 120A!Apart from that, what tip is suggested for small electronics? Mostly through-hole components, though maybe a tiny bit of SMT tweaking? The soldering station is temperature-controlled so it should be pretty simple to prevent overheating of components.Also, what do you guys suggest about grabbing some type of flux pen to help clean the wires/pads/etc. before soldering? I think we already have multi-core solder.

author: rs20
author_rank: Super Contributor
timestamp: May 01, 2015, 01:07:15 am
content: Quote from: yash101 on May 01, 2015, 01:02:32 amYou've got an instructorguessingthat it would melt the copper, and several people on this thread who have tried it andconfirmedthat that's not the case, and in fact it works great and is now their go-to method. Just sayin'.

author: edpalmer42
author_rank: Super Contributor
timestamp: May 01, 2015, 01:17:32 am
content: Quote from: yash101 on May 01, 2015, 01:02:32 amWhy on earth would you hold the torch on the connector for that long? All you're doing is heating it up enough for the solder to melt. Takes so little time that you'd be done before you had time to read this message!On the other hand, if you use a soldering iron or gun that's not up to the challenge, the heat will spread down the wire and melt or burn the insulation. Ugly!Ed

author: yash101
author_rank: Contributor
timestamp: May 01, 2015, 01:20:31 am
content: Alright! I've never used a propane torch, so another question about that:Smoke alarms! They always bite when performing combustion reactions. On a pretty low temperature setting, would a good propane torch create a lot of smoke?Also, what about Butane torches? Are they viable for soldering wires?

author: Fsck
author_rank: Super Contributor
timestamp: May 01, 2015, 01:43:28 am
content: your electronics teacher is a total moron for even thinking a propane torch can easily melt that much copper.a lot of heating radiators are copper and they're soldered.smoke alarms aren't an issue for propane torches, should be no smoke generation other than from the flux. I use one to sear meat often.butane torches work well too, but are usually low volume output in comparison to propane torches and refills are usually more expensive (for me).I actually have a butane soldering iron and a propane torch. I have both large output and precision tops for the propane torch and they work magnificently so I've basically shelved the butane iron. I'd take a propane torch over a soldering gun any day.most people like chisels for general purpose soldering.if you're using new components and good solder, you shouldn't need extra flux, but if you do I go with kester 951.

author: Rick Law
author_rank: Super Contributor
timestamp: May 01, 2015, 01:44:30 am
content: Quote from: yash101 on May 01, 2015, 01:20:31 amPropane pumbers' torch is better than butane - the torch head is designed for soldering and propane is hotter than butane. (Quicker and also less/no carbon black soot over butane). No, you wont have smoke alarm problem. Set the flame low - just high enough to see the 1inch to 1.5inch blue inner part of the flame.It is also convenient because in quick movement, I can put the heat shrink on and very quick (sub-second) pass with propane over the heat shrink to finish up without even switching tools.By the way,that is exactly where I first saw it done with propane - FRC Robotics at my daughter's high school. I can picture the stuff you are trying to solder. We are probably talking about the exactly the same battery connectors and cables (and probably from the same supplier) I was dealing with.Before that, when I tried "the old fashion way" with my 60Watt iron to fix the 10AWG connector to my UPS battery, it was a mess. Now it is a no-brainer with the torch.If you don't feel comfortable with it, practice a lot first in OPEN SPACE. It works well, but it is a lot of power (heat), it needs extra care and it is dangerous. Just an aiming error could cause a big disaster.Quote from: edpalmer42 on April 30, 2015, 07:11:17 amPrecision torch! I didn't even know they existed.For me, I merely have a regular pumbers' torch. For 10AWG, the wire jacket often gets very slightly deformed but not melted at least not visibly so. Next time I am at the hardware store, I have to see these precision torch - just for the curiosity factor.

author: yash101
author_rank: Contributor
timestamp: May 01, 2015, 01:56:22 am
content: Awesome, guys! One of the reason why I came here is because of the expertise of it's members.I have another noobish question.How do I hold the wires together when soldering? I typically use two people, each to hold one wire. However, that seems very dangerous! Perhaps there's a more effective/efficient method?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 01, 2015, 01:57:54 am
content: A tip: soldering big wires is generally a bad idea. There must be a better way to do it. There is: crimp terminals. For 12AWG, 1/4" quick connect terminals will be fine. For #8, you might be better off with screw terminals or bigass lugs. Unfortunately, the big lugs generally specify a special crimp tool, but you might get a good enough tool (often electrician's pliers or diagonal cutters will have the crimp nubs carved in them) for cheap from Harbor Freight or <insert cheap store here>.If that's not good enough for whatever reason, then get a reasonably powerful iron -- my 60W Hakko will do #12 without too much trouble, given a little extra time, and #8 in modest time (assuming the lug it's connecting to isn't also massive).Tim

author: Rick Law
author_rank: Super Contributor
timestamp: May 01, 2015, 02:01:51 am
content: Quote from: Fsck on May 01, 2015, 01:43:28 amForget even radiators, think about the toilet or faucet. All modern water pipes in the USA are copper pipes and they are all soldered - with propane torch.You may think the pipes are thick, but the pipe adapter (joining one size to another), couplers, caps, angle joins are all very thin 1/8 max to mostly 1/16 inch thick. They wouldn't even come close to melting during soldering.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 01, 2015, 02:06:35 am
content: FWIW, an average plumber's handheld propane torch is only capable of delivering a few hundred watts into the work. The total thermal output is probably under 500W. (Hmm, anyone got consumption specs handy for one?)Tim

author: yash101
author_rank: Contributor
timestamp: May 01, 2015, 02:09:28 am
content: I'm sure it's easy to calculate the power.I think I'll check out a propane torch. Does anyone know of some dirt cheap torch which will solder well?

author: Rick Law
author_rank: Super Contributor
timestamp: May 01, 2015, 02:20:09 am
content: Quote from: yash101 on May 01, 2015, 01:56:22 am1. Prime the cable. The FRC stuff I was dealing with come with the jacket pre-stripped but the remainder of the jacket still on the loose end that you can pull off by hand. So just pull the off, flux and prime the cable. (ie: put some solder on the stripped part of the cable.) Aim the flame AWAY from the jacket point the flame towards the cut end of the cable as you prime.2. Use a desk-vice grip to hold down the connector, clean, flux, heat it up, prime the darn thing.3. Inspect both connector and cable to ensure it is properly primed. Crimp it in (or not). Crimping it as much as you can is a good thing. It will take a lot of abuse during competition.4. Now apply solder generously.5. Tape it down. Cover as much of the exposed as possible to avoid accidental shorts. You may know electronics, most of the others on the team don't. You want to avoid the slightest chance of accidents.6. I like to apply a layer of heat shrink before the taping. But remember, it may need to be removed very quickly too. On the field repair is not uncommon.The smart teams are those who would replace their battery whenever given a chance - if your team is like that, make sure the nuts are aligned properly for quick replacement. There was a false start that one time, just 20-25 seconds into the match. The smart team came out toreplace ALL their batteriesbefore restart. 20-30 seconds is a quarter of the match time! You used up a lot of your battery's prime time. When you have to push the other guy out of the way, fresher battery wins. (The other guys are probably using the exact same motor you are using. So, strength is reduce to how much juice is in your SLA.)EDIT: Have to add this: Make sure you practice a few time in wide open space. The common mistake is to move your hand (while the flame is still on) and pointed it at the wrong angle. If you havemore than one person around while soldering, they would be all huddled to watchwhat is going on, and perhaps try to learn something. As you remove the torch, naturally, it will sweep an arc of your arm's movement. The other people around could get burn easily.Make sure you tell them to watch out for the torch as well.

author: edpalmer42
author_rank: Super Contributor
timestamp: May 01, 2015, 02:30:43 am
content: Quote from: Rick Law on May 01, 2015, 01:44:30 amI didn't know such a thing existed until I saw it in a flyer. I grabbed one in case it was a special purchase, but it looks like it's just regular stock. Here's the one I got:http://www.princessauto.com/en/detail/precision-burner-torch/A-p0140084eThis is a Canadian source. I expect it's available elsewhere, but I don't know where.Ed

author: Fsck
author_rank: Super Contributor
timestamp: May 01, 2015, 02:32:52 am
content: Quote from: edpalmer42 on May 01, 2015, 02:30:43 amI have the exact same one. the closest thing I've seen to it elsewhere are for jewelry soldering.

author: Rick Law
author_rank: Super Contributor
timestamp: May 01, 2015, 03:11:32 am
content: Quote from: yash101 on May 01, 2015, 02:09:28 amMine is Bernzomatic from home depot. You will find it in the pluming. This is the exact one I used. Suffice to say, battery connectors soldered using this model of propane touch have won a number of FRC competitions, so it is FRC field-proven.(Watch out, competition sites may not allow open flame, so make enough so you don't need that kind of field-repair.)This is the link, this one looks exactly like mine.http://www.homedepot.com/p/Bernzomatic-UL100-Basic-Propane-Torch-Kit-334458/203665003You may find a similar one at Walmart. Walmart at times has the same stuff butsmaller. I suspect it is so they can sell a pack of pepperoni (3.5oz) less than the local grocery store (5oz) without it being actually cheaper. I was wondering how come my pack of pepperoni from Walmart usually doesn't last as long, until I took time to check and realized I was paying more all along - less $ per pack but far smaller a pack.In this case, a smaller propane tank would actually help. Precision is a lot easier with a smaller tank.By the way - do not buy the kit unless you also do pluming! Theflux and solder for pluming is not suitable for electronics. They are acid based.Rick

author: Rick Law
author_rank: Super Contributor
timestamp: May 01, 2015, 03:18:07 am
content: Quote from: Fsck on May 01, 2015, 02:32:52 amThanks Fsck & Edpalmer42... That is now in my (potential) resource list as something I may want.

author: pickle9000
author_rank: Super Contributor
timestamp: May 01, 2015, 03:23:52 am
content: I do a little stained glass from time to time and an 80 watt stained glass iron with 1/4 - 1/2 inch chisel tip works very well. Works on copper plate as well. 5 minutes to heat up though.

author: Rick Law
author_rank: Super Contributor
timestamp: May 01, 2015, 05:47:41 am
content: yash101,By the way, what is your team number and region? (PM me if you don't want to disclose it in public)My daughter is no longer engage in FRC, but we still may watch to as she may want to show support for her former team mates. If I do watch the webcast of the competition, I will cheer for your team. (Well, that is, unless you are up against my daughter's former team...)Rick

author: yash101
author_rank: Contributor
timestamp: May 01, 2015, 06:02:15 am
content: I'm on Team Paradise 1165.

author: Rick Law
author_rank: Super Contributor
timestamp: May 01, 2015, 04:34:03 pm
content: Quote from: yash101 on May 01, 2015, 06:02:15 amParadise huh! An interesting name indeed. I think St. Louis is already over this year, so I have to wait till next season to see you. But when we watch, I will give a few cheers for a fellow blog forum member.Go get your torch and have some practice during the off-season for yourthick (>=10AWG) cables10 AWG or thicker cables (ie:<=10 AWG cables) I think you will impress the hack out of your team mates next season.Good luck.RickEdit:Thicker than 10 AWG of course has a smaller AWG number than 10; I think you guys know I mean to use the > in terms of thickness but not the AWG number. Eitherway, corrected so as not to be confusing.

author: eas
author_rank: Frequent Contributor
timestamp: May 01, 2015, 04:46:20 pm
content: Quote from: Fsck on May 01, 2015, 02:32:52 amThat looks like the top part of a common butane torch, kludged on to a propane tank. I imagine it might be jetted differently too.My father had a Bernz-O-Matic torch from the early 70s with three tips and accompanying jets. There was big honker, and also one that produced a very narrow, fine flame. There was also a soldering iron tip that fit over one of them.Oh, by the way, I managed to melt copper water pipe, once, with a propane torch. It took some doing though, and an insufficiency of flux.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 01, 2015, 05:09:08 pm
content: Quote from: eas on May 01, 2015, 04:46:20 pmShort sections won't be too bad. You'll need a firebrick to do it on, of course. Which begs the question, why not stack up a few and make a sort of furnace?With reflective and/or insulating blocks, you can do a pretty good job for, say, a few ounces of copper. Or do brazing with small to medium sized steel pieces (use borax as flux!).If you want "permanent" electrical connections, you can use Stay-Silv (it's self fluxing on copper), which melts at only red heat.Tim