Help needed for winding problem

[Joe Gwinn]

I use a 40W iron... I have no idea how hot that gets, but I do know that I haven't been able to melt the insulation on Stew-mac wire. I tried too.

What's the make and model of the iron?

Most of the wire I use know says 155 or 170 on the label. Isn't that the temperature that the insulation melts at?

No, it's the maximum service temperature.

I always use a lighter to remove the insulation anyway.

Works if one has a dab hand, but shouldn't be needed. Tends to oxidize the copper if held very long, which will weaken the very fine wire, and/or make it hard to solder.

[David King]

I'm not convinced that solderable wire is really going to make a secure connection without being scraped first. Even if you only get a 1% failure rate over a decade, I would say this is still too high. I have a soldering iron with adjustable temp and even on the highest setting (950º) I'm not getting reliable results w/o removing the insulation first.

Every time I try to tin the wire it just dissolves into the solder and breaks the moment the insulation finally melts.

The only thing I can think of is that my flux core isn't up to the task somehow. What solder are you all using?

[John_H]

This is from a couple years ago. I've been using aspirin ever since.

I just came across this forum and I'm amazed. I would never have believed that an arcane topic like pickup winding could have such a lively group of contributors! Gentlemen, it is an honor.

Anyway, getting the insulation off the wire is such a pain and usually you break the damn thing. I could never get to grips with the sandpaper. Luckily years ago a local guitar whiz showed me a great trick (Thank you Peter Langerak). You can dissolve the insulation using acid. The particular type of acid he recommended was acetylic acid, which can easily be obtained by melting an aspirin with your soldering iron. Please note, paracetamol or similar will not do! It must be good old fashioned aspirin.

How does this work? Well next to my winder I have a hot soldering iron of course and sitting in a safe burn free place a piece of aspirin. Just touch the aspirin with your well tinned iron and gently run it over the piece of wire you want to check. The insulation will disappear and the wire will become tinned giving a perfect place to make a reading.

You don't have to remove anything from the winder, if you need to continue just reinsulate this spot. I use thin alcohol based shellac and give the whole coil a good basting while I'm at it.

This makes winding to a specific resistance much easier and really takes the headaches out of the whole operation, which is what aspirin are famous for anyway I guess.

regards

[Joe Gwinn]

This is from a couple years ago. I've been using aspirin ever since.

Be very careful of the smoke. Do not breathe it, not even a little.

[John_H]

Be very careful of the smoke. Do not breathe it, not even a little.

Very true! I'm sorry I should have mentioned that.

[chevalij]

This is from a couple years ago. I've been using aspirin ever since.

Oh man, this I have to try!!!

[Joe Gwinn]

I'm not convinced that solderable wire is really going to make a secure connection without being scraped first. Even if you only get a 1% failure rate over a decade, I would say this is still too high. I have a soldering iron with adjustable temp and even on the highest setting (950º) I'm not getting reliable results w/o removing the insulation first.

I'm suspicious that your iron is not achieving the stated temperature. I've soldered lots of this kind of wire, and a large-enough iron at 800 F works instantly, in a little puff of smoke.

One can measure the temperature of a soldering-iron tip with a thermocouple, some black iron wire, and some rock-wool insulation. And a multimeter.

Every time I try to tin the wire it just dissolves into the solder and breaks the moment the insulation finally melts.

How long does this take, in seconds? It very much sounds like the iron is too cool, and 950 F is actually far too hot.

The only thing I can think of is that my flux core isn't up to the task somehow. What solder are you all using?

I use various kinds of 63-37 solder, usually made by Kester. The roll on my bench is marked Alloy SN-63, Flux 281, Core 58, Dia 0.040". I used this stuff because that's what RCA used when soldering the electronics for the moon lander radars in the 1960s, so I figured if it was good enough for NASA it was good enough for me.

One can also buy paste flux for application to terminals before soldering. I use Kester formula SP-44, which comes in a little 2-ounce plastic "tin", and is sold by Newark or Allied or the like.

Don't tell anybody, but for refractory cases, I sometimes use plumbers grease flux, the stuff one uses for copper pipes. This requires careful cleanup, and is really only for emergencies. The flux residue will probably corrode and break fine wire, but for larger wire it does work. I first used plumbers flux when assembling a Heathkit Vacuum Tube Voltmeter in the 1960s, before I knew any better. I still have that VTVM, and there is no corrosion to speak of. I no longer use it, as DMMs are far better, but it served me well. My Heathkit RF generator, assembled in 1975, uses the 63-37 radio solder.

I also sometimes use the tin-lead solder with 2% silver, but mainly for added strength and shiney surfaces. Perhaps it dissolves less copper when molten; I haven't researched the issue. It would make a good question to ask a solder manufacturer.

[chevalij]

Oh man, this I have to try!!!

Doesn't work with a crap with PE. Is this for poly wire only? If it is, my irons hot enough to melt it away.

[salvarsan]

I use various kinds of 63-37 solder, usually made by Kester. The roll on my bench is marked Alloy SN-63, Flux 281, Core 58, Dia 0.040". I used this stuff because that's what RCA used when soldering the electronics for the moon lander radars in the 1960s, so I figured if it was good enough for NASA it was good enough for me.

63-37 is the minimum-melting or eutectic lead-tin alloy; it melts and solidifies sharply instead of progressively as does 60-40. Cold solder joints are harder to create and easier to spot.

I also sometimes use the tin-lead solder with 2% silver, but mainly for added strength and shiney surfaces. Perhaps it dissolves less copper when molten; I haven't researched the issue. It would make a good question to ask a solder manufacturer.

In addition to mechanical strength benefits from a lesser tendency to form voids, Ag-2% solder leaves the silver plate intact on multistrand wire, particularly the teflon-insulated wire made popular by the space program of the 60's.

-drh

[Joe Gwinn]

63-37 is the minimum-melting or eutectic lead-tin alloy; it melts and solidifies sharply instead of progressively as does 60-40. Cold solder joints are harder to create and easier to spot.

Yep. That's why NASA had us use it.

In addition to mechanical strength benefits from a lesser tendency to form voids, Ag-2% solder leaves the silver plate intact on multistrand wire, particularly the teflon-insulated wire made popular by the space program of the 60's.

I had not heard this one, although it ought to work. NASA used miles of teflon-insulated silver-plated copper wire, but I don't recall that any of the solder we used on NASA projects was silver bearing.

I got the idea to use silver bearing wire for electronics from a famous book on vacuum tube amplifiers, so famous that I don't recall the name.

[David Schwab]

I could have sworn I answered this, but I must not have ht Submit.

What's the make and model of the iron?

Just something cheap. But I did wind a pickup tonight and just soldered the magnet wire to the leads, without removing the insulation, and that worked fine.

I have to get a new soldering station.

[David Schwab]

Every time I try to tin the wire it just dissolves into the solder and breaks the moment the insulation finally melts.

Are you trying to tin the magnet wire? I never had luck with that.

Here's what I do, and tonight I wasn't stripping the insulation off first. I tin my hookup wire, and then I wrap the magnet wire around the tinned end, which is about 1/4". Then I heat that wire end with the magnet wire wrapped around it and melt some solder on the connection. I hold the iron on for a moment or two until the hookup wire is getting hot on my hand, and that's it.

I did a number of tests on short lengths of magnet wire, and I got consistent connections every time. So then I tried it on two coils and it worked great.

[gtrplr2]

Wow, this has turned into a great thread for me to watch, I am learning all kinds of different information about wire and the nuances of winding, this is a good place for me to be! Since my last post, I have successfully wound 4 more Strat pickups without any problems with the high ohm reading I had encountered at first. I think most of my problem was being too careful (scared) when soldering the coil wire to the lead wire, by not leaving the iron in contact with the eyelet a bit longer than I was, anyway it seems to be working out fine, for now at least. I am using the Stew Mac 42ga wire at this time, and am not stripping any of the insulation off at the ends, so I must be lucky with my technique.

[David Schwab]

I am using the Stew Mac 42ga wire at this time, and am not stripping any of the insulation off at the ends, so I must be lucky with my technique.

It probably works. I still have two partial rolls of the Stew-mac stuff, so when I get a chance I'll test it.

But I used a couple of different brand wires today (Elektrisola, and Phelps-Dodge) and it worked on both of them without stripping the insulation off first..

[gtrplr2]

Yes I am a bit leery of NOT stripping the ends from reading some of the recent posts; I guess I will try stripping a few "loose ends" that are lying around from my previous bad winds. I have not done any experimenting with different wire yet, but I intend to after this roll of Stew Mac runs out, which should be soon. I am particularly interested in the early 50's winds that Fender was doing back then. It seems that Fender used "Formvar: for the Strat until 64, when they used a "Formvar/Enamel" wire. I am thinking about the Formvar 42 ga heavy build from Mojo, as I posted in a previous reply. I have never heard of Elektrisola or Phelps-Dodge, but I hope to find different sources for wire as I progress.