How to solder enamel coated wires

Hi all...

In front of me I have two big output transformers for HiFi project and the secondaries are enamel coated wires and when I have dealt with such wires in the past and had some trouble stripping the enamel coating before soldering I would like to ask you guys about how you do it?

I have used everything from fine grained sand paper to a small razor to scrape of the enamel coating... time consuming and very tricky.


Best regards

/John

Are you sure it is enamel?
Can you check if it is polyimide coated magnet wire?

Gus said:

Are you sure it is enamel?
Can you check if it is polyimide coated magnet wire?

Click to expand...

Thank you Sir


No, I do not know how to do that... I was just assuming they are enamel coated... well the problem is that they can't be soldered just as is. It is transformers from Sowter and I am not sure what kind of solid wire they use in their transformers.

Would it be a difference in how to treat them before soldering?

Best regards

/John

I always thought you dip them in a solder bath like with HF-litz wires.

Thank you Sir

I have seen that on pictures but I do not have such a "bath". I guess it has something to do with temperature as well?


best regards

/John

Get one of those lighters that's like a blow-torch and heat the end until it glows orange. That should burn off any non-metal impurities. Then coat it in flux and try to tin it with a leaded solder.

squarewave said:

Get one of those lighters that's like a blow-torch and heat the end until it glows orange. That should burn off any non-metal impurities. Then coat it in flux and try to tin it with a leaded solder.

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Thank you Sir

I'll try that ... absolutely


Best regards

/John

squarewave said:

Get one of those lighters that's like a blow-torch and heat the end until it glows orange. That should burn off any non-metal impurities. Then coat it in flux and try to tin it with a leaded solder.

Click to expand...

Ill generally clean the wire with alcohol in between so the flux doesnt have to work so hard and I get a better tinning

I've used sandpaper and physical abrasion in the distant past. I generally avoid such wire, but have a roll in my back lab, untouched for decades.  I used to use it to wind simple coils around output resistors in prototype power amps.

JR

I bet those auto body fiberglass pens would do it. 

I simply apply enough heat and the enamel - or whatever that covering usually is - comes off. I don't know the exact temp but my Weller WTCP soldering iron tip "7" doesn't quite produce enough heat, but the "9" tip serves this purpose well.

Kingston said:

I simply apply enough heat and the enamel - or whatever that covering usually is - comes off. I don't know the exact temp but my Weller WTCP soldering iron tip "7" doesn't quite produce enough heat, but the "9" tip serves this purpose well.

Click to expand...

Yes, a flat tip with a bead of solder on it at higher than normal temp.  This acts as a mini solder bath.

Perhaps ask Sowter how they would handle it. I’ve found the people at Sowter very responsive and helpful in the past. Brian Sowter himself actually emailed me about some issues I was dealing with.

mjrippe said:

Yes, a flat tip with a bead of solder on it at higher than normal temp.  This acts as a mini solder bath.

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Right, totally forgot to mention the bead of solder. As much as you can fit the tip really.

Thank you guys

It seems to be the old story ... either mechanical way of removing or heat.

About Sowter and Brian: Yes, they are very helpful in most cases and they have actually soldered the tips of the wires but I need to shorten them quite a bit.

Anyhow... I will experiment with heat. Alcohol might solve some of the problems. Unfortunately I do not have a massive soldering iron... It might be an investment for the future.


Best regards

/John

A piece of fine sandpaper always worked for me.
Or scrape off the coating with a sharp knife.

RuudNL said:

A piece of fine sandpaper always worked for me.
Or scrape off the coating with a sharp knife.

Click to expand...

Thank you Sir

Yes, even for me but when the wires are thin it gets a bit tricky... to med that is


Best regards

/John

Different insulation marterials have different temperatures they break down at . Some solder up easily some doesnt at all.
Depending on the gauge of wire you have to be carefull about the amount of heat and flame you expose it to.
With very fine wire if you use a gas torch you'll simply be left with a weakened and oxidised strand of copper that wont stand soldering probably . If you want to gauge the wire its important not to damage it before you use the calipers on it. also if the wire is very thin by the time youve scraped it off theres almost nothing left .
What I do with thin wires is use a cigarette lighter ,holding the wire at the blue part of the flame is hot enough to break the  insulation down , the yellow /orange part of the flame is much hotter ,so I keep away from that .