What's the best way to pre-tin wire? - Page 1
Forum section: electronics / beginners

author: geratheg
author_rank: Regular Contributor
timestamp: July 24, 2014, 09:32:21 am
content: I read that to pre-tin wire you apply the iron to the opposite side that you apply the solder.Doing this takes a long time to heat up the wire and melts the insulation. Is this normal?I have a Hakko fx888 station.I find it works better to touch the wire with the iron, and then quickly touch the solder to the iron and let it melt, then move the solder to the opposite side of the wire from where the iron is.Is this method proper or does this cause problems?

author: KJDS
author_rank: Super Contributor
timestamp: July 24, 2014, 09:34:21 am
content: put some solder on the iron before applying it to the wire, then add solder from the other side. ...but the best way is with a solder pot.

author: mariush
author_rank: Super Contributor
timestamp: July 24, 2014, 09:55:49 am
content: Tinning by handTinning using solder pot :Note that these are videos made with some stricter rules (avionics, nasa etc), in practice you don't have to be that paranoid about cleaning the solder and the wire that often but it doesn't hurt to make a habit out of it.

author: jmoreland79
author_rank: Regular Contributor
timestamp: July 24, 2014, 05:27:21 pm
content: You want to use a solder bead on the tip of the iron to melt the solder. Lead free (didn't say what kind you were using) solder melts around 225 C and I imagine you have your iron set up around 400 C. So applying the iron to the conductor is eventually going to heat the wire much hotter than it needs to be and then of course the insulation will melt.It may also help to just turn down the iron a little. While it may be faster to have a hotter iron, you also run into issues like this one.

author: zapta
author_rank: Super Contributor
timestamp: July 24, 2014, 05:52:13 pm
content: Quote from: geratheg on July 24, 2014, 09:32:21 amOne option is to use teflon wires. They do not melt.A local surplus store here sells them cheaply by the feet and this is what I use.

author: mariush
author_rank: Super Contributor
timestamp: July 24, 2014, 05:55:00 pm
content: Another explanation may be that you're using too thick solder wire.Get some thinner solder wire AND cut a small piece of the wire instead of feeding it directly from spool. If it's on spool, some heat will be absorbed through the length of the solder wire.I have 0.56mm solder wire (63/37) and I have no problems tinning at 300-350c set on the station.

author: geratheg
author_rank: Regular Contributor
timestamp: July 24, 2014, 07:34:02 pm
content: I'm using 350 CelciusKester 44 Rosin Core 63/37 Solder 0.031"I find it works best if I feed the solder in between the wire and iron first, and then start feeding from the opposite side. For some reason it just melts better that way, I don't know if this is the proper way.It's either due to the flux being released (Rosin Core) when I melt the solder with the iron first, or the molten solder somehow touches and aids in melting new solder from the opposite side.But is this going to cause cold solder joints or anything?Or is it okay to solder this way?

author: jmoreland79
author_rank: Regular Contributor
timestamp: July 24, 2014, 07:49:55 pm
content: Quote from: geratheg on July 24, 2014, 07:34:02 pmThe molten solder will melt the feeder solder faster than the tip of the iron. It's basic: a liquid transfers heat much more quickly than a solid.Also the solder is not as hot as the iron so it gives you more time to complete the tinning before heating the conductor to the point it melts the the insulator.That is the best method if you have to do it by hand.

author: IanB
author_rank: Super Contributor
timestamp: July 24, 2014, 08:57:33 pm
content: The way I tin wires is to coat the bare wire end with flux, then place a solder bead on tip of the iron, then run the solder bead down the wire while holding the wire pointing downwards, adding a little extra solder along the way if needed.It is similar to drag soldering, and also a bit like creating a tiny "solder pot" on the end of the iron.When people say to "add solder from the opposite side from the iron", they are really misleading you. The way everyone actually solders in the real world is to apply solder at the interface between the iron and the work. The solder will then melt on the iron and the liquid solder will provide a good path for heat conduction from the iron to the thing being soldered. A dry iron will not heat up a dry joint in a satisfactory manner.

author: ConKbot
author_rank: Super Contributor
timestamp: July 25, 2014, 01:12:58 am
content: Quote from: mariush on July 24, 2014, 09:55:49 amStrict rules, he wasnt even wearing gloves like NASA requires!If there is anything sort of nit-picky thing a hobbiest should take from that video, its to tin the soldering iron before you put it back in the holder. It makes a big difference on tip life.

author: geratheg
author_rank: Regular Contributor
timestamp: July 25, 2014, 01:17:16 am
content: Thanks for all the responses.

author: jmoreland79
author_rank: Regular Contributor
timestamp: July 25, 2014, 01:42:46 pm
content: Quote from: ConKbot on July 25, 2014, 01:12:58 amWhat I got from that is NASA is incredibly inefficient if they have technicians sitting around spending 2-3 minutes tinning one wire strip instead of just buying pre-coated wire.

author: ConKbot
author_rank: Super Contributor
timestamp: July 25, 2014, 10:24:06 pm
content: Quote from: jmoreland79 on July 25, 2014, 01:42:46 pm

author: Smokey
author_rank: Super Contributor
timestamp: July 26, 2014, 04:28:11 am
content: Quote from: IanB on July 24, 2014, 08:57:33 pmWhat he said.A good point here is the part about flux. If you just put a ball of solder on the tip of your iron and then try to tin more than a couple wires with it, it will get all crusty and oxidized and won't flow on anything. I almost never do more than one wire per application of solder, and then wipe it off and go again with a new shot from the flux core.

author: VK5RC
author_rank: Unknown
timestamp: July 26, 2014, 05:13:58 am
content: Agree with above, plus I also just pause a little while after the two components have 'wetted' with the solder/flux to allow the flux to fully chemically react, I think you also boil spare flux off and out of the joint but I haven't done any advanced soldering courses.

author: vk6zgo
author_rank: Super Contributor
timestamp: July 26, 2014, 06:28:50 am
content: One trick if you are tinning thickish wire,& have some very thin solder,is to put liquid flux on the wire,wind 2-3 turns of the skinny solder round the wire,then touch with the iron.The wire tins immediately.Obviously,this won't work with thin wire,as you will end up with a big blob of solder,but with the thick stuff,it's very effective.

author: Smokey
author_rank: Super Contributor
timestamp: July 26, 2014, 07:39:53 pm
content: Quote from: vk6zgo on July 26, 2014, 06:28:50 amThat's a really good idea. I was just struggling with a good tin on some really big gauge wires in a reasonable amount of time. I'm totally going to use this one. Thanks.