Cable / wire - soldering - Page 1
Forum section: electronics / beginners

author: hneve
author_rank: Regular Contributor
timestamp: November 18, 2015, 07:48:20 pm
content: Hi,I need some advice on wiring cable.I use protoboards a lot and always have the problem with the insulation shrinking and causing shorts, I am aware of this and usually inspect my work thoroughly before applying any power. sometimes i use melting glue to be safe.Now I'm running low on this shitty cable and would like some advice on what cable to get.I am on a super tight budget so if you have some ebay or ali links with something that's good and doesn't shrink i will be forever in your debt. (I'm talking beer, not my soul)

author: suicidaleggroll
author_rank: Super Contributor
timestamp: November 18, 2015, 08:09:07 pm
content: Anything with a PTFE or silicone rubber jacket should stand up to soldering temperatures without running away.

author: fleuroman
author_rank: Contributor
timestamp: November 18, 2015, 11:56:40 pm
content: magnet wire, you can get it from small inductors or vibrating motors, its insulated until you scuff off the insulation to solder it... it can be hard to solder/scuff off the insulation but anywhere the insulation is, it wont short

author: Rick Law
author_rank: Super Contributor
timestamp: November 19, 2015, 02:04:09 am
content: Quote from: hneve on November 18, 2015, 07:48:20 pmI am no expert but I got burned a few times with this problem too. So I came up with a two-part solution.1. Pre-shrink the insulation of the cable before soldering:First, I strip much less insulation from the wire than what visually appears to need for the pad. I apply some solder to the stripped part and heat it longer than the time it takes to actual soldering it to a pad. That shrinks the insulation resulting in more copper/non-insulated wire to expose, I trim some if too much un-insulated wire is exposed. Now when I actually do the soldering, with it "pre-shrinked", it wont shrink much more during actual soldering to the pad or to whatever.2. If critical, I also use a bit of heat-shrink tubing. After soldering, just slide the heat-shrink down to cover any re-exposed wire due to insulation shrinkage.Lastly, same as you - with some critical points or wire that may be pulled on (such as for V-in/V-out), I use hot glue to give it additional cover.

author: rdl
author_rank: Super Contributor
timestamp: November 19, 2015, 03:23:27 am
content: I'm pretty sure this is why connectors were invented. It's also probably why places like Mouser and Digi-Key seem to have more different types of connectors than all other electronic components combined.

author: Simon
author_rank: Unknown
timestamp: November 19, 2015, 06:43:04 am
content: but he needs to wire parts together. Variation in wire is as much about insulation as the metal cable. Try alpha wire from farnell and others, their cheapest is not top but pretty decent.

author: tron9000
author_rank: Frequent Contributor
timestamp: November 19, 2015, 09:45:54 am
content: Quote from: rdl on November 19, 2015, 03:23:27 amYeh but OP is on a budget - seen to price of tooling on some connector systems.Cheapest I could recommend is this - there's bound to be an ebay knock off:MOLEX 63811-1000 CRIMP TOOLGood for molex KK range - which are dirt cheap, in 0.1" pitch, decent positive locking.

author: Ian.M
author_rank: Super Contributor
timestamp: November 19, 2015, 10:03:34 am
content: If you are using solid wire, consider wirewrap. Its not just the 30 AWG Kynar we've all seen, you can also get 24 AWG tooling, and you cant get cheaper wire than self-salvaged CAT5 cable (not patchcord)!

author: KL27x
author_rank: Super Contributor
timestamp: November 19, 2015, 11:56:14 am
content: Nothing wrong with 30AWG. 99% of my PCB jumpers are 30AWG kynar. If you keep them short and can stand the voltage drop, there's no problem, even up to a couple of amps. For the heavier power conduction, I might use 26AWG or larger kynar jumpers. But 30AWG is plenty for modest power transmission across short distances and for most signals.The thinner the wire, the less heat is transferred down the wire while soldering it. This not only reduces the melting of the insulation, but it also allows you to make really short jumpers without having issue of reflowing the first joint while doing the second. And kynar is pretty decent at not shriveling up. Much better than polyester or vinyl insulation.The other benefit of kynar wrap wire is that it's silver plated and it wets crazy easy. Very rarely would you need to dip the end into flux or pre tin. This also reduces your propensity to melt the insulation.Kynar wire also strips very easily.Kynar is also very thin and flexible. For your jumpers, you generally want the wires to stay where you bend/put them and to not be too bulky, which means solid wire with a thin, flexible insulation. Kynar wrap wire is pretty hard to beat, here. 30AWG might look fragile, but IME, any thin, flexible, solid core wire is more reliable for jumpers/intraconnects than even much thicker stranded wire that pops up and gets exposed to flexing at the joint. Keeping a low profile and staying put is more important than the tensile strength.For all these reasons, kynar insulated solid wire is very handy for jumpers.PTFE is essentially impervious to soldering temperatures, but it's a PITA to strip. And it's relatively expensive - mostly used in aircraft, marine, and military applications. I bought a few different gauges of Teflon wire, thinking it would be great for jumpers. Nope. I only use it on rare occasions.Small gauge magnet wire might be handy in a pinch for very high density of jumpers to fine pitch pads/leads. The lacquer insulation is even thinner and more flexible than kynar. But magnet wire is also a PITA to strip. I've seen some guys use it, extensively, but I only touch it where kynar won't work.For interconnecting cables, yeah, stranded is typically preferred. And use the hotmelt glue to tack the wires down somewhere away from the joint. For some reason, I have never seen stranded kynar wire, so I use solid kynar for cables quite a bit.

author: rdl
author_rank: Super Contributor
timestamp: November 19, 2015, 02:12:54 pm
content: Don't overlook using IDC connectors with header pins. Channel-lock pliers or a vise work fine for IDC.For the Molex KK and SL style you can find cheap crimpers that will work , even bead crimpers will work. You may need to add a dab of solder just to be sure. The crimp housing will hide any melted ends.Soldering crimped connections is generally frowned upon because it creates a flex stress point where the solder joint ends, but if you're soldering wire to board you already have this problem.

author: hneve
author_rank: Regular Contributor
timestamp: November 20, 2015, 10:15:34 pm
content: Thanks for the good options, the cable I'm finally getting to the end of is actually cat5 cable, and the insulation on that melts and shrink just by looking at it. I'll look into what I can find with the options mentioned.

author: KL27x
author_rank: Super Contributor
timestamp: November 21, 2015, 12:42:23 am
content: Familiar footsteps. Protoboard and cat5 is where I started out. Yeah, that has problems. I remember well how the insulation melts and pulls back or even peels off the end of a jumper. The exposed copper doesn't always wet very easy, either.CAT5 has to be 26AWG to conduct signals because it needs to be able to do this over 100's of feet. Wiring a circuit on a protoboard, it's usually major overkill for anything under an amp.Here's the best price I could find on 30AWG. I have purchased from this seller several times. You make your jumpers short as possible and/or bend the extra wire so it lays flat between other components/leads. To me, 30AWG kynar is the currency of making/reworking circuit boards, like sandpaper is to woodworking. Gotta have it, and lots of it.http://www.ebay.com/itm/500-ft-KYNAR-wire-wrap-30-awg-ANY-COLOR-/200406828268?hash=item2ea92d84ec:m:mtEDK_i-plTl-Iw9TsY5EJw

author: hneve
author_rank: Regular Contributor
timestamp: November 21, 2015, 05:59:22 pm
content: I got a tip on the sideline here that I think might benefit others.Flat ribbon cable. I had a few lengths and tried it out, @300celsius it didn't shrink at all, I think I have a winner.

author: fpliuzzi
author_rank: Regular Contributor
timestamp: November 21, 2015, 09:05:27 pm
content: As an additional option you might also try 'CAT5e plenum' cable. Its insulation meets specific ANSI requirements to be flame retardant and I find that it holds up pretty well to soldering temperatures. Over here its available at the local Home Depot and Lowes.

author: edavid
author_rank: Super Contributor
timestamp: November 21, 2015, 10:14:53 pm
content: I am very impressed with UL1061 wire... the insulation is Semi-Rigid Polyvinylchloride (SR-PVC). It is easy to strip, and it does not pull back at all when soldered.

author: hneve
author_rank: Regular Contributor
timestamp: November 22, 2015, 04:14:34 pm
content: by the way, i hear you talk about trouble stripping wire ?What tool are you using ? I can only say that the only wire i have come close to troubeling with stripping is transformer wire, and that wasnt too hard.

author: edavid
author_rank: Super Contributor
timestamp: November 22, 2015, 04:19:35 pm
content: Quote from: hneve on November 22, 2015, 04:14:34 pmTry some teflon (PTFE) wire and get back to us...

author: KL27x
author_rank: Super Contributor
timestamp: November 22, 2015, 08:11:33 pm
content: ^yeah, I have a roll of 30AWG PTFE. I made a rotary razor blade wire stripping tool, specifically for this kind of wire.Hneve, check out this videohttp://vid18.photobucket.com/albums/b103/klee27x/Public%20Service%20Announcement_zpsycns37ge.mp4This is just one reason why 30AWG kynar is ideal for making circuits on protoboard. I think some of the other suggestions are not directed at what you need it for. Anything else is a waste of time, money, or space, for protoboard jumpers.

author: suicidaleggroll
author_rank: Super Contributor
timestamp: November 22, 2015, 08:48:46 pm
content: Quote from: edavid on November 22, 2015, 04:19:35 pmI use ptfe all the time and have zero problems stripping it. What kind of strippers are you using?

author: KL27x
author_rank: Super Contributor
timestamp: November 23, 2015, 12:18:58 am
content: Try stripping 30AWG PTFE with an ordinary sharpened notch stripper or flush cutters. The best result I could get is to eventually make a split down the side of the insulation and have to pull the wire out the side. The stuff is very malleable and shear-resistant. It will flow through the tiniest gap in the stripper and lengthen, instead of tearing.The form-fitting round notch strippers might work fine on larger gauges. They don't even make them for smaller AWG.That said, there are probably different forumas for the Teflon insulation. Some stiffer and some more gooey.

author: suicidaleggroll
author_rank: Super Contributor
timestamp: November 23, 2015, 02:06:08 am
content: Quote from: KL27x on November 23, 2015, 12:18:58 amFlush cutters? Why not use a pocket knife or a sharpened tin can lid?Use any set of real strippers and it's not a problem. It's not like they're expensive...This is what I use, goes all the way to 32 awg:http://www.amazon.com/Klein-Tools-11057-Tools-Kurve-Stripper/dp/B000XEUPMQ/ref=sr_1_22?s=hi&ie=UTF8&qid=1448244240&sr=1-22&keywords=wire+stripper

author: KL27x
author_rank: Super Contributor
timestamp: November 23, 2015, 02:19:31 am
content: Well, I am mistaken. They DO make round hole strippers for 30AWG. And they might even work on 30 AWG Teflon. I wouldn't bet my life on it.QuoteBecause flush cutters are handy, and you might be using them to cut the wire and/or component leads, already?QuoteThe other kind of stripper that fails on 30AWG teflon is the adjustable white/yellow/black doohickey with the opposing V blades that costs $30-50.00. Not a chance of a clean strip.http://www.amazon.com/Jonard-ST-500-Adjustable-Precision-Thickness/dp/B007A1Y986/ref=sr_1_9?ie=UTF8&qid=1448248396&sr=8-9&keywords=32+awg+wire+stripperAnd I dunno, I have a collection of wire strippers, and I never wanted one in the style of the Klein. Not necessary for large gauge wires, unless you're using doing a lot of connections. Not very handy for smaller gauges.Watch the video I linked in the previous post. This is what makes kynar wire easier to strip, and why it makes a difference for specific applications. It also strips like a breeze with regular flush cutters. Not so good with a knife or a tin can lid, though. Ironically, a knife was the best way I could strip the Teflon wire, initially. In conjuction with a pair of needlenose pliers, and a lot of fiddling.If you want to use a Klein stripper to make dozens of 0.3" long jumper wires out of tiny gauge Teflon wire, good luck with that and tell us how that works out.OP isn't repairing one bad power conductor. He's making circuitry on protoboards.