Re: solderig enamelled wire, problems.

On Mon, 23 Jun 2025 12:44:18 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:

<albert@spenarnc.xs4all.nl> wrote:
 

I remember soldering coil/transformer wire was simple in the 70's.
The trick was putting the wire an aspirin tablet and 0.1 mm was no
sweat.
 
Now for the 1v-5v step up converter I followed the advice, and remove
the winding of a 5x5 mm ferrite coil and replaced it with a bifilar
wire with the same number of turns. This was surprisingly easy.
.35 mm wire with 2*.25 wire. (The wire was stolen from a broken
ventilator.)
 
Now I get stuck. I can't solder the wire! The aspirine trick doesn't
work. Burning the insulation turn it into a black coating that
is equally tenacious. Making the copper redhot to burn the coal,
only make the copper to melt.
 
Groetjes Albert

 
 
Put some methylated spirits or ethanol in a small open metal container
such as the lid of a bottle .  Set fire to it and hold the end of the
wire in the flame until it is red hot.  Plunge it downwards into the
liquid and slide it out sideways so it doesn't get heated a second time.
 
There will be a chemical reaction between the oxide on the red hot
copper and the ethanol, which removes the oxide and leaves the wire
bright and clean.
 
Have a piece of metal ready to put over the container to extinguish the
flame and plan in advance how you will deal with the rapidly-spreading
fire if you upset the container.  Put the bottle of ethanol some
distance away.

I'll have to try this.  The ethanol has to be acting as if it were
producer gas or the like.

>
Fun. I’ll try it outdoors sometime, but not at my bench!
>
A less exciting approach is a bottle of GC Strip-X. I don’t know if it’s
still available—I don’t recommend using that as a search term. :(

Is that GC, or MG Chemical?  GC makes mechanical strippers these days.

The right answer is probably a solder pot.

Which won't work with Formvar coatings at all.  There are stripped
mechanically, with rotating rubber eraser wheels that wear plastic far
faster than copper.

What would also work would be a small pot of hot lye solution.

I've used the melted aspirin tablet approach, and it does work, but
the smoke is quite noxious.