Tinning Litz wire - Page 1
Forum section: electronics / beginners

author: Chris Wilson
author_rank: Super Contributor
timestamp: July 24, 2015, 04:01:40 pm
content: I have a temporary loan of a drum of heavy Litz wire. I am winding a loading coil for an LF transmitter with some of it, but tinning it has defeated me. I do not have a solder pot (but might be interested in buying one if was quite cheap...), so have used liquid flux and a hefty iron on full heat. The wire strands just blacken and will not accept solder. Am I right in thinking a caustic based paint stripper like Nitromors might remove the enamel, or even boiling caustic soda? I am in the UK, so international product names welcome!Thanks.

author: owiecc
author_rank: Frequent Contributor
timestamp: July 24, 2015, 04:28:46 pm
content: Boil some aspirin tablets and dip the wire in the solution.

author: m98
author_rank: Frequent Contributor
timestamp: July 24, 2015, 04:51:22 pm
content: Dip the wire in some paraffin oil/glycerin/refined(!) cooking oil, thread it with sandpaper and solder through the oil coat.If that doesn't do the job, then just try liquid Lithium.

author: apis
author_rank: Super Contributor
timestamp: July 24, 2015, 04:56:27 pm
content: Quote from: Chris Wilson on July 24, 2015, 04:01:40 pmIf you're going to boil NaOH, don't forget safety goggles and be outside. A drop of that in the eye and you are blind for the rest of your life.

author: ciccio
author_rank: Frequent Contributor
timestamp: July 24, 2015, 05:14:14 pm
content: Solder pots can be cheap:http://www.ebay.co.uk/itm/1pc-220V-ST-21C-150W-Solder-Pot-Soldering-Desoldering-Bath-50mm-450-Degree-/181788252861?pt=LH_DefaultDomain_3&hash=item2a536c9abdQuote from: owiecc on July 24, 2015, 04:28:46 pmNever hears of this: how does it work?Best regards

author: SeanB
author_rank: Super Contributor
timestamp: July 24, 2015, 07:10:02 pm
content: Take some solder, flatten with a hammer and wrap around the wire, then use a cigarette lighter to burn the wrap till the solder melts off, the rosin cleaning the wire and putting some solder on it so you can then finish tinning it with a large iron and more solder. Do where the molten solder can fall onto something that will not burn, I use a wet newspaper, placed in an open plastic bag, underneath, as it is easy to ball up after and throw away.

author: Stray Electron
author_rank: Super Contributor
timestamp: July 24, 2015, 07:40:05 pm
content: Where on earth did you manage to find Litz wire???Each fiber within each strand is individually insulated so you're not going to be able to remove the insulation by any mechanical means (unless you want to untwist the stuff and clean each fiber separately!) Insulation is probably some kind of lacquer or plastic, I expect that you'll have to use some kind of solvent to dissolve it or try to break it down by heat but that will leave a residue that will probably prevent the solder from sticking. You might try "Lacquer thinner". It's not as common as it once was but they used it extensively when they painted cars with "lacquer paint". Many show cars still use lacquer paint.You'll need to do something to prevent any solvent from creeping too far up the wire because of capillary action.

author: owiecc
author_rank: Frequent Contributor
timestamp: July 24, 2015, 08:08:38 pm
content: Quote from: ciccio on July 24, 2015, 05:14:14 pmNo idea. But it works. Smells funny too

author: G7PSK
author_rank: Super Contributor
timestamp: July 24, 2015, 08:39:48 pm
content: Raid the missus makeup supplies for nail varnish remover.

author: Chris Wilson
author_rank: Super Contributor
timestamp: July 24, 2015, 09:13:40 pm
content: Thanks for the ideas so far. I have tried cellulose thinners, sadly it has no effect, as I have gallons of the stuff as I'm in the motor trade. I will try neat acetone tomorrow, I use that for de-greasing alloy and stainless before TIG welding. If cellulose thinners doesn't remove the lacquer I doubt acetone will. The aspirin idea sounds "different", the wife will have some, God knows she's always saying she has a headache these daysThen I'll try the other ideas, too. I will take care with boiling caustic soda, I realise it's nasty stuff. Then I guess it's time to make a Heath Robinson solder pot. I wonder if the old Baker's Fluid flux liquid is worth a shot?I'll be sure to report back with results, thanks, other ideas, mild to wild welcome!

author: IanB
author_rank: Super Contributor
timestamp: July 24, 2015, 09:51:00 pm
content: I would try some of this:http://www.polycell.co.uk/product/polycell-advanced-paint-stripper/(Or a similar product)

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 24, 2015, 10:18:31 pm
content: A drum? What's the drum say? Is it labeled at all? Who made it? How big (AWG equivalent, cross sectional equivalent, number of/bundles of strands)?If the enamel is any kind of "Sold-ease" type (usually polyester base), it can simply be soldered through. This is a little awkward by hand with an iron, but can be done. Use lots of solder, extra rosin, high temperature (350-450C) and take your time. The enamel will turn to a bubbly, acrid mess, partly on its own and partly dissolved by the excess flux.It takes me a few minutes to do one end of 10 AWG equivalent material (which has red enamel, I think a 140C Sold-ease variety?). A temperature controlled iron will do a fine job.If it's not a solderable type (enamel (in the true sense of the word -- vintage stock only?), or any of the high temperature polyimide or etc. types), you're SOL and need to do it the hard way.Chemical strippers include methylene chloride (the active ingredient in any quality stripper) and other nasties, and agents (usually molten salts) to burn off the layer. NaOH, as mentioned, can be used; in combination with potassium nitrate (KNO3, yeah, the stuff used in gunpowder) might be handy, too. These can be melted in a stainless steel spoon over a flame. Definitely use eye protection (NaOH will murder eyes on contact*), and clean up carefully afterwards (NaOH will absorb moisture from the air to form a solution, spontaneously, so don't leave it out in the open; store it dry, or dissolve and wash it away).*On that ever-so-long list of chemical hazards to beware of (during those moments before you put on your safety goggles): apparently, strong mineral acids (sulfuric, nitric, etc.) aren't very fatal to the eyes. Dangerous, yes; hurts, you damn well believe it; but amazingly, not damning. Apparently, the body has some innate capability to tolerate or neutralize acids. Strong base, though, say goodbye to proteins and cell walls, that stuff just toasts everything.That's why NaOH is used to sanitize anything that needs to bedamn well sanitized(like medical instruments and breweries), and why nothing grows in alkaline lakes (yet there are endless cases of bacteria, and sometimes higher life forms too, growing in acid mine drainage and similar environments!).Tim

author: bills
author_rank: Frequent Contributor
timestamp: July 24, 2015, 11:04:07 pm
content: after a quick search,some links.http://www.litz-wire.com/dipstripop.phphttp://www.cardas.com/litzhttp://www.audiokarma.org/forums/showthread.php?t=282190

author: albert22
author_rank: Regular Contributor
timestamp: July 25, 2015, 01:58:12 pm
content: So many years that I don use litz wire, I dont remember very well how I soldered it.Try burning the enamel in the flame of a cigarette lighter. It has to be quick because the thin wires melt very quickly. The burnt enamel is very easy to scrape or may be it can be soldered without scrapping.

author: Chris Wilson
author_rank: Super Contributor
timestamp: July 25, 2015, 02:21:31 pm
content: So far heat has failed, even a naked flame, but having some success with dichloromethane based paint stripper. I am also going to try boiling caustic soda. The wire is old, you can from the wooden reel it's on, the enamel does not react to heat in anything like the same way modern enamelling on single core copper wire does. The paint stripper I have a a bit too viscous to penetrate into the wire bundle well without a lot of manual agitating. Something with a more water like viscosity would be better. I have a feeling boiling caustic may be the answer. Thanks for the ideas, I will report back once I try caustic soda.

author: G7PSK
author_rank: Super Contributor
timestamp: July 26, 2015, 08:31:42 am
content: If it is really old wire the enamel could well be shellac so that would dissolve in alcohol and the threads are likely to be silk which wont melt at soldering iron temperatures.