I keep melting the cable plastic - Page 1
Forum section: electronics / beginners

author: Charkel
author_rank: Contributor
timestamp: March 17, 2021, 01:18:51 pm
content: I either melt the plastic on the covered part or the shrinking tube gets so hot it shrinks in the edge. Which is almost worse because you think "Phew I did the connection... but hold on a sec!"I know i can make longer cables to get the shrinking-tubes away from the heat but I ain't got much to work with on this project. It's those small nasty 0,3mm cables or whatever and they not long on one of the two parts. It's a computer mouse cut too close to the mouse partIm I using to much heat? Or is my tip too big? Or am just applying the heat for too long because I'm a noob?Here is pictures of soldering tips, iron and cables:Lemme give you a real closeup of the cables (DISCLAIMER: Experienced solders might cry after seeing this mess):Here is the soldering station I am using. It's pretty good, fast heating etc.:https://www.amazon.co.uk/HQ-Digital-Soldering-Station-30U/dp/B00CVUAV60Model: HQ SOLDER/30U,Temperature accuracy: 8 °CHeat range: 160 °C - 480 °C,Display: LED,Power: 48 WThank you for sharing your wisdom.

author: bobbydazzler
author_rank: Regular Contributor
timestamp: March 17, 2021, 01:44:13 pm
content: If you're shrinking them with your iron then 160c is probably too hot, I just checked my heatshrink and it has 125c written on it(which I assume is the shrinking temp). Your minimum iron temp is 160c so you could wrap some foil around the barrel and touch the wires with that or just use a candle/lighter(hold the flame next to the wire not under it).Your soldering skills don't look awesome, I usually dip the tip of a wire in my flux jar before soldering them because that way you can put the solder on the iron then bring it to the wire and it flows great. You also need to tin each wire separately before joining them.

author: Benta
author_rank: Super Contributor
timestamp: March 17, 2021, 02:00:54 pm
content: Don't solder stranded cable. Use crimp connectors. Much better.

author: Charkel
author_rank: Contributor
timestamp: March 17, 2021, 02:16:14 pm
content: Quote from: bobbydazzler on March 17, 2021, 01:44:13 pmI was blazing at 230-300c xD Been working with thick wires.And I do always flux and tin all ends. I'll try a lower temp and maybe a smaller tip.Quote from: Benta on March 17, 2021, 02:00:54 pmDang it I have the male part but not female. They pretty thicc tho. I guess I have to find a really small size then?

author: kjr18
author_rank: Regular Contributor
timestamp: March 17, 2021, 02:54:44 pm
content: You can use those bullet shaped ones. Sometime ago I got some unusual connectors, not really a connector as you connect both cables to one piece, but how it's named? I don't know.

author: Charkel
author_rank: Contributor
timestamp: March 17, 2021, 04:13:56 pm
content: You don't mean Soldier Seal Shrinks? Those looks so easy to be true gonna try to find somehttps://cdn.shoplightspeed.com/shops/609908/files/17890620/600x700x2/solder-seal-heat-shrink-butt-connectors-awg-16-14.jpg

author: Gyro
author_rank: Super Contributor
timestamp: March 17, 2021, 04:33:29 pm
content: Big Clive did a video on those. Results were a bit mixed...

author: Charkel
author_rank: Contributor
timestamp: March 17, 2021, 04:37:06 pm
content: Quote from: Gyro on March 17, 2021, 04:33:29 pmAah one of my favourite youtubers. Will give it a watch right away thx!

author: bobbydazzler
author_rank: Regular Contributor
timestamp: March 17, 2021, 06:07:10 pm
content: Quote from: Gyro on March 17, 2021, 04:33:29 pmTakeaway was they might struggle slightly with <20 awg wire but otherwise were good, that was the first time he tried them too. Wrapping a ring of solder around the center of the join might add enough extra solder, or maybe add a small amount of flux.

author: james_s
author_rank: Super Contributor
timestamp: March 17, 2021, 06:50:49 pm
content: Some wire has insulation that melts really easily, it can be a pain to solder. A trick I use is to wrap a strip of wet cloth or paper towel around the insulated part to keep it cool. Also for shrinking use hot air, not a soldering iron. I often use the exhaust port of a butane soldering iron for small stuff but a heat gun works better for larger things.

author: Gyro
author_rank: Super Contributor
timestamp: March 17, 2021, 07:18:52 pm
content: Quote from: bobbydazzler on March 17, 2021, 06:07:10 pmIt's a shame Clive didn't try adding a bit of flux. I don't think ordinary solder would help (melt), but the ring of low temperature stuff from the shrink sleeve never seemed to get to a nice 'wetting' consistency. Flux might have an effect, but again the temperature might be a bit too low.

author: mariush
author_rank: Super Contributor
timestamp: March 17, 2021, 07:34:49 pm
content: Just use a gas lighter, or plain match sticks ... hold flame a couple inches away from the heat shrink materialI sometimes used regular scented candles or you can make your own ... I shoved a bunch of cotton balls in a small cup and poured sanitary alcohol in the cotton balls and then inserted a bit of string as filament inside the cotton balls.

author: Charkel
author_rank: Contributor
timestamp: March 18, 2021, 05:10:47 pm
content: I'm talking about the heat of the soldering shrinking the tube BEFORE i'm done.When done I shrink it with a bic lighter

author: Stray Electron
author_rank: Super Contributor
timestamp: March 18, 2021, 06:16:56 pm
content: Quote from: Charkel on March 18, 2021, 05:10:47 pmIt's no wonder that you're melting the wire insulation! A lighter flame is too hot and too uncontrollable. After years of struggling with matches and other heat sources, I finally picked a temperature controlled hot air gun and it works great! Look on E-bay for a used Commercial Grade one, not many people are interested in them and they usually sell cheaply. Or do as Muriash said and try an alcohol flame. It burns cooler so it should be easier to manage than a butane lighter. Tip: even 70% Rubbing Alcohol available from any drug store is flammable. Denatured alcohol is purer and should be available in any hardware store. You might also want to consider an alcohol lamp with a blow tube like those that used to be used for basic chemistry. Theycanput out a lot heat or high temperatures depending on how hard you blow on the tube. Look herehttps://www.mccrone.com/mm/how-to-makemodify-and-use-an-alcohol-lamp/It would be easy to even make your own using a small jar and a piece of cotton rope for a wick.You might also try a different brand of heat shrink. Some of the cheap stuff is almost impossible to shrink. The GOOD stuff will shrink with little heat.

author: Gyro
author_rank: Super Contributor
timestamp: March 18, 2021, 06:39:48 pm
content: I think the OP is referring to melting the insulation and accidentally shrinking the end of the heatshrinkbeforehe applies flame or hot air.

author: Microdoser
author_rank: Frequent Contributor
timestamp: March 18, 2021, 07:20:11 pm
content: I also find that the insulation pulls away from the solder area. I strip extra insulation from the outer cable so the heatshrink can be away from the source of heat. Not an ideal solution but it does work. You have to then use extra of the larger heatshrink or vulcanizing tape.I like the idea of using soaked tissue to stop the insulation melting and heatshrink shrinking. I'll give that one a go myself.

author: RJSV
author_rank: Super Contributor
timestamp: March 18, 2021, 09:33:59 pm
content: Strayelectron: You got it, bull's eye perfect. Use a heat gun, that's all I thought, reading through replies.When you get stuck, on desert island, no AC power: THEN you dig out your lighter / torch / phosphorus torch... If you got power, and can afford that special tool, buy a temp controlled hot air gun.Then you can get back to your good work, there.

author: RJSV
author_rank: Super Contributor
timestamp: March 18, 2021, 09:50:06 pm
content: Oh yeah: and plus I mis-read your second question, problem where your soldering heat starts acting on the shrink tube, before done soldering wire, so you can't slip it over the recent connection.WHY, can't you just prepare the cable, as there is room to strip that a bit more. So your heat shrink piece is way back away from soldering heat. Then, simply slip it over the newly (cooled) joint, and plus you could, optionally, place a large diameter piece of shrink wrap over the whole thing, after each individual wire is done, with soldering and covering w the shrink.That sounds like overkill, but the large outer shrink segment gives a neat, finish appearance to your cable.It may make cable stiff along there, if that's OK.

author: Nusa
author_rank: Super Contributor
timestamp: March 18, 2021, 09:51:13 pm
content: Quote from: Charkel on March 17, 2021, 01:18:51 pmHave you considered opening up the mouse and replacing the original lead entirely with your new one? That avoids a splice right next to the mouse that's going to be constantly stressed by mouse movement.

author: JustMeHere
author_rank: Frequent Contributor
timestamp: March 18, 2021, 11:42:10 pm
content: Soldering stranded wire will not last. It creates a shear point and the wires moving around that point will crack and break.It's best to use a wire nut or crimping. They make some snap connectors too.

author: kjr18
author_rank: Regular Contributor
timestamp: April 02, 2021, 08:40:25 am
content: Quote from: Charkel on March 17, 2021, 04:13:56 pmNope, not those. More likethese ones.I think these are the same as mine

author: Zero999
author_rank: Super Contributor
timestamp: April 02, 2021, 09:25:16 am
content: Quote from: james_s on March 17, 2021, 06:50:49 pmThat works.For the type of insulation which shrinks lots, I don't bother stripping the wire. I cut it, dip the end in flux, load the iron with solder and dip the wire in it. The insulation just shrinks back and the wire is tinned.

author: Terry Bites
author_rank: Super Contributor
timestamp: April 02, 2021, 11:14:25 am
content: Use the correct tool- a heat gun. Not an iron or a paint stripper or a blowtorch and it will all go well.

author: Psi
author_rank: Super Contributor
timestamp: April 02, 2021, 11:40:41 am
content: After inserted the heatshrink and moving it along the wire, out of the way, I hold the wire and heatshrink together using my finger and thumb. This allows me to both hold the wire in place and monitor the temp of the heatshrink while soldering to ensure it wont shrink in the wrong location due to the wire heating up. If I can hold it without getting burnt then I know it has not started to shrink prematurely because that only happens at a temp way to hot to touch.If you use your thumb and index finger to hold the wire+heatshrink then your other 3 fingers can hold the solder wire and move it around to solder the joint. Your other hand holds the iron.Also, each joint should only take ~1-3 seconds to solder, if it's taking you longer then you either have a dirty wire that needs flux or have a soldering iron that is not powerful/hot enough.Sometimes you will come across wire with really bad quality insulation that melts super quickly while soldering. It can be quite annoying sometimes.

author: wizard69
author_rank: Super Contributor
timestamp: April 02, 2021, 07:49:39 pm
content: I will make some comments below that might help but first I'm going to offer up a different opinion. Sometimes the best way to fix a cable it to replace it. In this case no matter what you do a stiff point will be built into your cable. Beyond that high flex cable does not have an infinite lifespan, most likely use as created other weak points. Beyond that there is a good possibility that the wire was heat treated or otherwise modified for high flex usage, soldering can impact such wires.So what I'm saying is that sometimes the right course of action is to replace the cable with either a new one or one salvaged from someplace else.Quote from: Charkel on March 17, 2021, 01:18:51 pmThat can easily happen and frankly some plastic insulations really are not meant for simple soldering. The plastics melting point is just too low for solder. This really use to be a huge problem for me when doing lots of DB connectors, a change to crimped fittings made a huge difference here.Your shrink tube issues though might indicate that you did not strip back far enough. If the tube is too close to a heat source it will shrink. As fr what happens when you actually want to shrink the tubing I've used every method under the sun and if you do it right you will not have problems. We except in one case and that is where the plastic insulation melts at a lower temp than the shrink tube. Note you may be able to save your self some grief by using the clip on heat sinks designed for soldering.QuoteIn this case it is foolish to try to save the cable in my mind. Change out the cable with a new or salvaged one, you will thank yourself for doing so. Beyond that having a big blob so close to the mouse will irritate you to no end.QuotePossibly both or neither. As noted some insulation just don't hold up under soldering temperatures. However poor soldering technique can be a huge problem with a newbie to soldering. I usually per a slightly hot iron and try to minimize contact time.QuoteSomebody mention crimps which would be good for this type of wire except for the huge blob that results. I would most likely try to replace the cable if this was my mouse.

author: Nusa
author_rank: Super Contributor
timestamp: April 02, 2021, 08:03:22 pm
content: Note the OP abandoned this thread and started a new one on the same subject some time ago:https://www.eevblog.com/forum/beginners/metal-strands-inside-cable/msg3520556/

author: IDEngineer
author_rank: Super Contributor
timestamp: April 03, 2021, 06:26:02 am
content: Nevertheless, I'll reply here for future readers.The easy solution to this problem is to keep a few bare alligator clips around. They act as heat sinks on either side of where you're soldering, so the wire on the other side doesn't get hot enough to melt its own insulation nor start shrinking the heat shrink.

author: Messtechniker
author_rank: Frequent Contributor
timestamp: April 03, 2021, 09:17:18 am
content: Another matter: the OP seems to solder his wires in mid-air. Clamping down one wire end in a sort of vice (or vise for our American friends) on a magnetic base - as depicted - makes good soldering in different places much easier.Of course the missus is missing one peg

author: camila
author_rank: Contributor
timestamp: April 03, 2021, 05:32:05 pm
content: use connector at those junctions!