# DIY De-Mag!



## MERLIncMan (Nov 22, 2020)

It seems a bit redundant to say "DIY" regarding anything on this site doesn't it....   

SO!

My sweetie responded, as sweeties do, to my complaints regarding my beard-cutter machine. You see, I had been using some old 110VAC clipper thing that I found somewhere, years ago. It was missing teeth and was dull, and so pulled the beard rather than cut the beard... the joys of long-term bachelordom

... Incidentally, a real man shaves with a sharp rock, using cactus for lather, and can strike a match on his chin, so there is that 

Anywho, I got a new beard gizmo, and so was left with something that worked fine, but had no use... If you're a hobby machinist, you know what a moral dilemma it is to consider throwing away something that works!

With fond boyhood memories of me gran'pappy teaching me about inductive coupling, using a similarly discarded hair-clipper-thing, I recalled that within these AC powered devices there is the simplest of oscillating motors: some bell wire around a laminated iron core.  Granddad turned that old one into a neat step-down transformer.

I recalled, when working at the Tool and Die Shop, having disassembled the de-mag once to fix its switch.  The function of the thing is immediately apparent: AC goes up and down to make a 60Hz oscillating magnetic field, this outlaws the freedom of assembly among the ferro-dudes within the steel, thusly demagnetizing the part (yes, it is a bit more complicated than that, but that's pretty much what it does).

I disassembled my former beard-cutting machine, removed the alarming amount of historic beard-hair that had secreted itself within (had it for many bristly days), cut the casing to expose the business-end of the electromagnet, then added a bit of stiff nylon tubing to act as a handle.

While modifying the case, it broke  but! As I intended to employ the omnipotent hot-glue-extruder, I carried on!

I cut out a chunk of Not-Leather (I think it was a bull**** purse or something from which I had made a book-cover for a friend) and applied it to the gaping hole as a makeshift "Flux emission window" (You see what I did there? Made it all officially scientific with snooty terminology!)

I then wrapped a lowe's shopping bag about the handle end to make it thicker, and covered the thing in the ugliest electrical-tape that I could find.

TADA!!! 

An Oscillating Flux Ferro-Randomizing Wand!!!

If you'll notice, as it is chincy as chincy can be, I must make use of more and more snooty terminology....

Anyways, put it near aluminum and the aluminum gets all angry - on account of Lenz and whatnot.
Put it near a drill-bit, and the fuzz will fall away of its own accord....
    (Come to think of it, it is still a beard-trimmer, in that it removes the iron beards from pieces-parts-and-tools! HAHAHAHAA!!!)

I demagged some screw-drivers, and it works exactly as anticipated.

Then Sweetie told me that some people want their screwdrivers to be magnetic, so I guess I've got to contrive a DC equivalent now to de-demag what was previously magged, but then was de-magged....

Anywho, two pictures show the thing - ugly and really simple.

In seriousness though, every de-mag I've seen has been a benchtop model - building one as a wand seems more intuitive.

.... I wonder what would happen if I put it near my metal detector wand?

Thank you for looking!


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## Bi11Hudson (Nov 22, 2020)

An interesting but not very original use for an old hair clipper. There are many devices that use a "short stroke" magnetic oscillator as a motor. Just listen for the buzz, after a while, you can call the 60 Cycle hum. I use a Weller D-550 soldering iron, it allows another use for a fully functional tool. 

I am severly alergic to magnetized screwdrivers(and other small tools) and having a soldering gun handy. . . If you have access to a color TV with an "old school" pictire tube(CRT), try waving it around in front of the picture. But *not* while Wife is watching soaps. It works on B&W TVs as well, just not as kaleidoscopic.

.


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## 7milesup (Nov 22, 2020)

I like it!!
I just picked a few pieces of metal out of my surface grinder tray and they were all covered in metal beard dust.  Now I will have to find something around here that vibrates at 60Hz.  I wonder if she still has that...


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## 7milesup (Nov 22, 2020)

I guess I might have to stop by Goodwill or similar.


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## MERLIncMan (Nov 23, 2020)

7milesup said:


> I guess I might have to stop by Goodwill or similar.



If you're really hardcore - get ye a microwave oven transformer and just cut out the secondary. That sucker will de mag the soul from your neighbor's cellphone.

Or, or.... hehehehe

Leave everything in the microwave wired up, but pull out the magnetron, and put a 15 degree cone around it... zap the mag off everything... no, wait, that would magnetize it... or irradiate it...

I don't know, but how cool would it be to have a magnetron gun? What's it for? If you have to ask, you wouldn't understand....


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## SLK001 (Nov 23, 2020)

I thought this thread was going to be useful.  I have some drill bits that have become so magnetized that they are almost unusable.   They became magnetized using them on the lathe, go figure.


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## MERLIncMan (Nov 23, 2020)

SLK001 said:


> I thought this thread was going to be useful.  I have some drill bits that have become so magnetized that they are almost unusable.   They became magnetized using them on the lathe, go figure.



Yes, the De-Mag is as important as waysoil really, but I haven't really seen it discussed.

If I had the facilities, I'd produce neat little mag/de-mag wands and sell them - they really are on the short list of must-have-tools for dealing with iron.

Rubbing iron on iron will make a magnet every time - doesn't seem like it should, but it will.

Glad I could help!


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## 7milesup (Nov 23, 2020)

SLK001 said:


> I thought this thread was going to be useful.  I have some drill bits that have become so magnetized that they are almost unusable.   They became magnetized using them on the lathe, go figure.



Errrrmmmmm..... well, I think if you follow Merl's instructions it would be useful.  The magnetron out of the microwave.....


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## tjb (Nov 24, 2020)

Bi11Hudson said:


> An interesting but not very original use for an old hair clipper. There are many devices that use a "short stroke" magnetic oscillator as a motor. Just listen for the buzz, after a while, you can call the 60 Cycle hum. I use a Weller D-550 soldering iron, it allows another use for a fully functional tool.
> 
> I am severly alergic to magnetized screwdrivers(and other small tools) and having a soldering gun handy. . . If you have access to a color TV with an "old school" pictire tube(CRT), try waving it around in front of the picture. But *not* while Wife is watching soaps. It works on B&W TVs as well, just not as kaleidoscopic.
> 
> .


So am I reading you correctly that a soldering gun can double as a demagnetizer?


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## RJSakowski (Nov 24, 2020)

Rather than a conventional tip, I use a coil of 6AWG copper.








						DIY Tool Demagnetizer
					

A few days ago, I commented in another thread about using a soldering gun for demagnetizing tools, parts, etc.  For a long time, I have used 10AWG copper wire for making my own soldering tips.  At one point, I reshaped one of the tips into a circle and it worked very well for demagnetizing screw...




					www.hobby-machinist.com
				




To properly use a demagnetizer, you insert to object to be demagnetized and slowly withdraw it from the loop before shutting off the current.  If you want to magnetize an object, insert it into the loop and power the gun on and off.  If you hit it just right, the current will be at a maximum and the object will be magnetized.  Pull it out and try to pick up some iron.  If not satisfied, try it again.
EDIT Although it is possible to magnitize aqn object in this manner, simply pulling a strong magmet over an object works better.  There must be a fair amount of carbon in the steel to magnetize it.


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## ericc (Nov 25, 2020)

I tried out a little tape head demagnetizer.  This thing is puny and has a difficult time even with the tip of a needle file.  Those needle files become annoying when covered in filings.


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## Bi11Hudson (Nov 25, 2020)

tjb said:


> So am I reading you correctly that a soldering gun can double as a demagnetizer?





RJSakowski said:


> Rather than a conventional tip, I use a coil of 6AWG copper.
> 
> 
> 
> ...



Since I work with small parts and tools, most times a regular tip on the D-550 works for me. On rare occasions, I need to DeMag something larger than the tip will accept. Like RJSakowski,, but with AWG-10 wire, I make a loop. Usually with a couple or three turns to intensify the field.

Magnetism is closely related to electricity. I could lecture for hours on the subject. That's how electricity is produced. . .  A soldering "gun" consists of a very high(?) reduction transformer that produces a *very low voltage*. Just a volt or two. There are several(!) web sites where a light duty welder is produced from microwave oven transformers. The same process is the resultant of a soldering iron. The only difference is a soldering iron uses a "closed loop" rather than striking an arc. 

As the voltage is reduced, current is increased. A soldering iron works because the large brackets and relatively small tip cause the tip to get hot from the high current flow. The same effect can be replicated with a welder. Shorting the output through a small wire will produce the same effect. The welder must be set to a relatively low "current" and the wire must be balanced in size to the rated current. Numerous coils may be necessary for the demagnatizing to be effective. These coils may be made with the welder's cable, so a quite large chunk of iron can be demagnitized.

To "magnetize" a piece of iron, a D-C welder will work better, as an A-C device is reversing 120 times a second. And, of course, D-C must never be applied to a transformer. Hitting the peak voltage is a hit or miss proposition, at best. The simplist method is to simply use a bar magnet and stroke the iron repeatedly. For very large items, you'll need a D-C welder or the like.

I have a D-C welder that I finagled from a Lincoln "Buzz Box", some 225 Amps max. The diodes are on the secondary of the transformer and are *enormous*. Each one about the size of my fist, rated at 500 Amps and a kilovolt. A generator would probably work better, but the diodes were salvage. The only cost was a piece of copper pipe for buss bars. And a lot of time.

As I said earlier, I could lecture for hours on the subject. This missive is becoming such a lecture, I've talked far too long. I cover the subject lightly in a document on my personal web site;
http://www.hudsontelcom.com/uploads/ShopElex.pdf 
It does not get too serious beyond a basic introduction. But it may be enough if the interest is there. The pointers in the bibliography are mostly for electrical subjects, but since the two are so closly related, each touches further on the subject.

Bill Hudson​
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## tjb (Nov 25, 2020)

Bi11Hudson said:


> Since I work with small parts and tools, most times a regular tip on the D-550 works for me. On rare occasions, I need to DeMag something larger than the tip will accept. Like RJSakowski,, but with AWG-10 wire, I make a loop. Usually with a couple or three turns to intensify the field.
> 
> Magnetism is closely related to electricity. I could lecture for hours on the subject. That's how electricity is produced. . .  A soldering "gun" consists of a very high(?) reduction transformer that produces a *very low voltage*. Just a volt or two. There are several(!) web sites where a light duty welder is produced from microwave oven transformers. The same process is the resultant of a soldering iron. The only difference is a soldering iron uses a "closed loop" rather than striking an arc.
> 
> ...


Thanks, Bill.
Great info.


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## GunsOfNavarone (Nov 25, 2020)

So if I'm following...you removed the blades, but regardless, if you put a magnetized (screwdriver) near a set of beard trimers, you would demagnetize the screwdriver?


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## sycle1 (Nov 26, 2020)

When I need to demagnetize my screwdrivers drills etc I just whack them against a steel bench leg and swarf be gone.
Works for me!


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## Bi11Hudson (Nov 26, 2020)

De-magnetizing screwdrivers is my most common usage. I stick the screwdriver between the brackets or inside the tip. Powering on the soldering iron and slowly withdrawing the screwdriver until it is a foot or two away from the soldering iron, then powering down (releasing the switch) the soldering iron. Sometimes two or three passes are necessary when the chemistry of the iron in the tool makes it more or less magnetic.

This *only works* on "induction" soldering irons. Many soldering irons use a heater internally. They take a couple or three minutes to heat up. An induction iron heats up in a couple of seconds, and cools almost as quickly. A Weller 8200 is rated at 100/140 watts. This is not the actual wattage used, rather a "heat equivilent" to a heater type.

Shock will remove a large portion of magnetism in many tools. And the shock also removes loose particles through inertia. My usage on the (wooden) bench is nowhere near the machines. While the soldering iron is on a bracket right at hand. My concern is steel screws and the like. Brass is nonmagnetic, but much "brass" hardware is actually *brass plated steel*. Good quality stainless steel is also non-magnetic, but lesser quality stuff is _somewhat_ magnetic. All of this is at play on my bench.

.

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## 7milesup (Nov 26, 2020)

Bi11Hudson said:


> Good quality stainless steel is also non-magnetic, but lesser quality stuff is _somewhat_ magnetic. All of this is at play on my bench.


I think that "good" quality or "lesser" quality depends on the application.  Martensitic steel is magnetic.  Austenitic is not.  Generally speaking.


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## Armourer (Nov 26, 2020)

7milesup said:


> I wonder if she still has that...



Mine uses battery powered ones


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## Bi11Hudson (Nov 26, 2020)

My comments about stainless steel were not intended as a judgement of value, but rather the metalurgical capacity of the steel. The term greater or lesser "quality" is referring to the metalurgical content, not the "value". I don't get hung up on semantics or charts, I use whatever is appropriate to a given situation, be it stainless, carbon steel, aluminium, or plastics. Each of which has numerous characteristics making it suitable or unsuitable for a given application. For example, stainless of any quality is not suitable for a motor. Nor is brass (or bronze) suitable for an electromagnet. Except, perhaps, as an alternative conductor to copper.

In my younger days(Ca.1966), when automotive radios had vacuum tubes, there was a "vibrator" that allowed the D-C of the electrical system to be converted to A-C so it could be applied to a transformer. In later years, I worked on (tubes again) process control equipment that used a vibrator for some esoteric reason. It used 120 VAC so wasn't related to the power supply. It was called a "chopper" in that application, but a vibrator is a vibrator is a vibrator. Or not. . .

Funny how "semantics" have altered over just 40 years. The "quality" now is taken as "value", where to old folks it has a wholey differnt meaning. I guess my 1945 issue of Webster's is just a door stop now.

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