Stripping Copper from Armatures & Motors

[rusty]

This is how I strip copper from transformers, starters, armatures and field coils from electric motors and welding generators.

First I would like to comment that it really matters which way the bevel side of your wood chisel is facing, when working with motor field coils make sure the bevel is face down as shown on the picture below otherwise you will find the chisel digging into the laminates.

Working with armatures the bevel should be facing outwards, and it really works best if the chisel is behind at least two laminated plates keeping the copper wire bridged. Always cut from the commutator end otherwise it makes removing the wire difficult after incineration.

For stripping transformers I cut a slit through the copper coil, all work has to be done before incinerating when the wire is still nice and stiff.

After incineration I tap the armature shaft on my anvil and the wire falls out, same thing for the motors. The transformers require a bit more work but the wire comes out easy.

For those of you with a sharp eye, yes the electric motor has aluminum windings but will suffice to show how easy it is to remove copper wire with little effort.

I do not have a truck or automotive starter field coil to show, I use the chisel to cut through one end of the coil then incinerate. once the copper wire is annealed it comes out very easy. Same gig tap the starter housing onto something solid and the wire falls out.

Remember you seen it here first.

 

[rusty]

Some additional pictures of the armature, after incineration the commutator copper segments come of easy. If you ever strip any large generator armatures be prepared for a large deposit of scrap mica.

 

[rusty]

The microwave transformer from my above post, now stripped and weighed.

The scrap yard would have paid me $0.25 a lb for this transformer whole, now that I have processed it I have 3.75 lbs of number 2 copper worth $3.00 a pound.

A good quality transformer will have the plates welded together, this eliminates any possible hum, an even better transformer will have welded laminates then the coil will be clad with a copper sheet to eliminate stray EMF from interfering with electronics such as high end stereo equipment.

Copper clad transformers should be sold, not stripped out for a couple of dollars worth of copper.

 

[skippy]

As to incinerating (burning?) the epoxy laquer coating, do you have any advice for minimizing the smoke?
My scrap yard has never minded me bringing in laquered windings with the rest of my #2 grade copper, so I have never felt the need to put fire to any transformers, but I do miss out on the copper from those small motor rotors like you pictured though.

It pays to be open minded, there's money in copper scrap as sure as in gold scrap.

 

[FrugalEE]

Rusty,

Very nice posts and I'm looking forward to trying some of that out. I have some Mil-spec type transformers that are sealed in metal cans with paraffin/tar type of potting inside. Have you ever dealt with any like that? I doubt any scrap yard would take them as is. The yard I use is quite dilligent in avoiding flourescant ballasts, probably because they might have PCBs in them.

 

[rusty]

Rusty,

Very nice posts and I'm looking forward to trying some of that out. I have some Mil-spec type transformers that are sealed in metal cans with paraffin/tar type of potting inside. Have you ever dealt with any like that? I doubt any scrap yard would take them as is. The yard I use is quite dilligent in avoiding flourescant ballasts, probably because they might have PCBs in them.

I try to avoid sealed tar filled transformers, you have to drill holes into the covers before incinerating to allow the gas's to escape while being incinerated otherwise you could have an explosion for each transformer not drilled.

Chances are your tar filled transformers are fairly small, I really don't think they're worth the effort, just send them to the scrap yard as breakage.

 

[lazersteve]

Gill,

I have a project I'm working on and I need a straight section of laminated core. The core needs to be 1.5" x 1.5" x 6" (give or take). PM me if you come across a piece of one of the transformers (or other devices) that has a core segment of these dimensions.

Great job on these instructional posts by the way.

Keep up the great work.

Steve

 

[rusty]

Gill,

I have a project I'm working on and I need a straight section of laminated core. The core needs to be 1.5" x 1.5" x 6" (give or take). PM me if you come across a piece of one of the transformers (or other devices) that has a core segment of these dimensions.

Great job on these instructional posts by the way.

Keep up the great work.

Steve

Steve from the second picture you can see the welded laminates as I suggest that you lay them out, I have laid then out roughly to give the idea of how it should be done the finished product core be much tighter.
.
You could bind the laminates together using dielectric tape then varnish the tape or tig or mig weld them together across the top and bottom then cut to length.

To polarize the core just wind a bit of copper wire around it then put some juice to it, if you need to know North from South a compass will show you which is which.

If this works for you let me know and I can save some material for you to build your laminated core.

On a side note, I used to buy portable welders that were on the bum, if a generator sits idle for years or is roughly handled or dropped even a short distance you can knock the polarity out of it. And it will not generate to weld until it has been re polarized, an easy fix using a 12 volt battery and a set of jumper cables, just a quick touch to the terminals will fix the problem.

Sometimes the commutator will become egg shaped and the carbon brushes will bounce, another easy fix. Pull the carbon brushes back in their holders then lean the spring against them to hold in place while you use a block of wood with sandpaper to true up the commutator while running the engine at an idle. Just remove the high spots.

Miller Big 40's have a pair of rectifier bridges, 9 times of 10 a wire has come loose or a rectifier has gone bad, every time I pull a microwave apart and find a rectifier bridge I'm reminded of my old hobby.

Worse case scenario with the Miller Big 40, Auckland's, Canox, Air Liquid portables is a split commutator ring.

 

[qst42know]

I have a project I'm working on and I need a straight section of laminated core. The core needs to be 1.5" x 1.5" x 6" (give or take). PM me if you come across a piece of one of the transformers (or other devices) that has a core segment of these dimensions.

You building a custom power supply Steve?

 

[rusty]

I have a project I'm working on and I need a straight section of laminated core. The core needs to be 1.5" x 1.5" x 6" (give or take). PM me if you come across a piece of one of the transformers (or other devices) that has a core segment of these dimensions.

You building a custom power supply Steve?

Maybe a Taser, wouldn't that be an electrifying experience.

 

[Juan Manuel Arcos Frank]

Nice work,Rusty!!!!!!!....Thanks for sharing it with us.

Kindest regards.

Manuel

 

[lazersteve]

You building a custom power supply Steve?

It's a back burner project. A mini-electric arc furnace that runs off of 120v mains.

Gill,

Please PM me with pricing on enough laminates for two cores as described if you can source the materials. All I need is the transformer laminates, I'll do all the fabrication.

Thanks,

Steve

 

[goldsilverpro]

I remember an old Report of Investigations (RI) published by the Bureau of Mines concerning the separation of copper from the armatures, etc. They used a molten salt bath of barium chloride or calcium chloride (I think). This melted the Cu only, which sank to the bottom and was tapped off periodically. They put the parts in a steel basket to dip them. The report also detailed how to prep the material - it has to be bone dry, of course, before putting it into the bath. I'm thinking the report was 20 or 30 pages long.

The B of M published 1000s of these reports over many years. Most were mining/geology related but some involved scrap. Some are impractical but some are pretty good. I used to be on their free mailing list and often I got 5 or 6 reports in a month. The reports are now hard to find. Sometimes, you see them sold on EBay.

Chris

The attachment is an example just to show you what they look like. It's the only one I have a copy of. Coincidentally, it involves Cannon type connectors, which is the topic of a recent thread.

 

[qst42know]

Chris

In your experience have these RI's ever gone over the same subject with a different approach?

 

[goldsilverpro]

Chris

In your experience have these RI's ever gone over the same subject with a different approach?

In my experience, they were always one-shot deals.

Here's a few for sale, although I see none involving scrap in this list. All mining stuff.
http://www.woodenski.com/2neat/usbm/usbmreportsofinvestigations.html

 

[qst42know]

You building a custom power supply Steve?

It's a back burner project. A mini-electric arc furnace that runs off of 120v mains.

Gill,

Please PM me with pricing on enough laminates for two cores as described if you can source the materials. All I need is the transformer laminates, I'll do all the fabrication.

Thanks,

Steve

Hey Steve is this along the same lines of what you had in mind?

http://www.americanbeautytools.com/site/models/rs/114#

 

[lazersteve]

It's a DIY project I found in a very old magazine on line. I'll post a link to the article later.

Steve

 

[qst42know]

Want to melt tungsten?

There is a photo gallery attached to this link.

http://www.popsci.com/diy/article/2004-05/melting-unmeltable

 

[Militoy]

I don't personally scrap out copper magnet wire - but we do send in several thousand pounds as #2 scrap a couple of times each year at work (I'm a magnetics Engineer). I had an old friend (now passed away) that made his living selling scrap - and he raised the value of his #2 scrap to #1 by the simple method of cooking the wire over a wood fire in a 55 gal drum until the HPN or HPTZ insulation turned to ash. Probably not advised in most city areas - but he lived in a remote part of the Mojave desert where a small trash fire is pretty much ignored. One of the reasons the rebuilders do the high-temp furnace burn-out is to raise the recovery price of the wire to the #1 level.

 

[rusty]

Refrigeration compressor cut open, since the compressor is considered to have a heavy duty cycle the windings are copper. You will never find aluminum windings inside a compressor.