The Ford Barn

ford35lh · 11-08-2018, 12:26 AM

I inadvertently magnetized my good Nicholson file.
Any suggestions to de-mag it ???

Drbrown · 11-08-2018, 12:36 AM

its the opposing ends of the file that are magnetized. I've hear of the something like the following: if you get/find another magnetized rod and touch the opposing ends together that they will cancel each other out and thus remove the file's magnetic field.

Pete · 11-08-2018, 12:47 AM

Quote:

Originally Posted by ford35lh

I inadvertently magnetized my good Nicholson file.
Any suggestions to de-mag it ???

If you have a solder gun, drag the file through the loop a couple times with the gun on.

Mike51Merc · 11-08-2018, 09:44 AM

Heat kills magnetism, unfortunately it also kills tempering in a file.

runmikeyrun · 11-08-2018, 09:56 AM

My shop teacher taught me a trick in high school regarding this.

Wrap a wire around the file in a coil from one end down to the other. Touch the ends of the wire briefly to your 12v battery. That will magnetize your item. Since yours is already magnetized, skip to the next step.

To de-magnetize, you need to use an AC current touched to the same coil of wire. If you have an old 12v AC “wall wart” you can snip the connector off and strip the ends of the wires to touch to your wire coil on the file. I would recommend against using line voltage (wall outlet) lol

Sent from my iPhone using Tapatalk

34pickup · 11-08-2018, 10:11 AM

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Quote:

Originally Posted by Pete

If you have a solder gun, drag the file through the loop a couple times with the gun on.

I have done this before.

deuce_roadster · 11-08-2018, 11:00 AM

RunMikeyRun,
I thought "wall worts" were transformers that converted AC to DC current.

runmikeyrun · 11-08-2018, 11:02 AM

Quote:

Originally Posted by deuce_roadster

RunMikeyRun,
I thought "wall worts" were transformers that converted AC to DC current.

They step voltages down and can make either AC or DC.

Sent from my iPhone using Tapatalk

rotorwrench · 11-08-2018, 02:03 PM

I used to magnaflux before I sold the machine. I still have the big AC demag coil and a gauss meter though. A lot of stuff I get back from the NDT shop is still magnetic so I run it through the coil. There are two ways to magnetize parts depending on the direction of magnetism you need. Shooting a strong DC current through the ends of a shaft will give the shaft a circular magnetism. Wrapping a coil around the shaft and hitting the coil with a strong DC current will induce a longitudinal magnetism through the shaft with north on one end and south on the other. In any case the shaft has to be draw through an active AC coil at a slow pace to completely demagnetize it.

Licensed to kill · 11-08-2018, 03:26 PM

Quote:

Originally Posted by Mike51Merc

Heat kills magnetism, unfortunately it also kills tempering in a file.

If you are referring the the soldering gun trick, it's not the heat that does the demagnetizing, it's the electricity traveling around the loop. Also, a soldering iron, used for this purpose doesn't get anywhere near hot enough to draw any about of temper out of a file.

Ronnie · 11-08-2018, 05:30 PM

Stop reinventing the wheel just do as this fellow does and no worries.I do knife sharpening and some customers knives are really magnetized and they get done like this all the time. Nothing to do with heat.

https://www.hobby-machinist.com/thre...netizer.65952/

R

john in illinois · 11-08-2018, 05:40 PM

I bought this simple tool years ago. It did not cost much. Turn it on and drag a tool or part accross it. It does not take up much space. I am sure it is just an AC coil in a box.

John

rotorwrench · 11-08-2018, 06:20 PM

Many of the soldering guns are induction type so they have a small AC coil. If I hold a shaft in the coil of my demagnetiser, it will heat up too. This old coil is 220 volt so it doesn't take much on small parts. It takes a bit more to demag a crankshaft though. Sometimes I have to pass it through several times or edge the long side up close to the coil & move it side to side a bit. A person definitely doesn't want any residual magnetism in something with any bearing journals. I check every part I send out just to make sure. I always get a kick out of letting my NDT guy know too. It's usually some new kid he hires that screws the pooch. We all learn by mistakes and I've made my share.

woodiejon · 11-08-2018, 08:39 PM

Just move on its no big deal.

fordor41 · 11-08-2018, 11:15 PM

some times you can hit it on a piece of metal a few times if it's not too magnetized

ford35lh · 11-13-2018, 12:14 AM

I was looking around for my Weller soldering gun when I saw
my armature growler buried on a bench.

(Blink) thats a light going on!

Plugged it in and held on tight.
Two passes and the file is back to normal again.

I still want to play with the soldering gun field
on one of the coming long nights.

Red98 · 11-13-2018, 08:28 AM

Subject the magnetized article to a strong AC field such as a Weller soldering gun open frame transformer.
Gradually reduce the field by reducing the gun's input voltage to naught. Either use a variac, or gradually increase the distance by slowly moving the article away from the field so its a good 3-4 feet away from the field.
Test by carefully subjecting the file to that vintage Patek Philippe watch your wife just inherited from her favorite grandaddy and see if you can dislodge the balance wheel. Then accidentally click the solder gun next to the watch.
Time to get some some exercise.

11-08-2018, 12:26 AM	#1
ford35lh Senior Member Join Date: May 2010 Location: Upstate; The Real New York Posts: 444	De-magnetize I inadvertently magnetized my good Nicholson file. Any suggestions to de-mag it ???

11-08-2018, 12:36 AM	#2
Drbrown Senior Member Join Date: Oct 2013 Location: Glens Falls NY Posts: 1,267	Re: De-magnetize its the opposing ends of the file that are magnetized. I've hear of the something like the following: if you get/find another magnetized rod and touch the opposing ends together that they will cancel each other out and thus remove the file's magnetic field.

11-08-2018, 09:44 AM	#4
Mike51Merc Senior Member Join Date: May 2010 Location: Northeast Pennsylvania Posts: 1,582	Re: De-magnetize Heat kills magnetism, unfortunately it also kills tempering in a file.

11-08-2018, 09:56 AM	#5
runmikeyrun Senior Member Join Date: Apr 2018 Posts: 124	De-magnetize My shop teacher taught me a trick in high school regarding this. Wrap a wire around the file in a coil from one end down to the other. Touch the ends of the wire briefly to your 12v battery. That will magnetize your item. Since yours is already magnetized, skip to the next step. To de-magnetize, you need to use an AC current touched to the same coil of wire. If you have an old 12v AC “wall wart” you can snip the connector off and strip the ends of the wires to touch to your wire coil on the file. I would recommend against using line voltage (wall outlet) lol Sent from my iPhone using Tapatalk

11-08-2018, 11:00 AM	#7
deuce_roadster Senior Member Join Date: Oct 2011 Location: Shelton, WA Posts: 3,800	Re: De-magnetize RunMikeyRun, I thought "wall worts" were transformers that converted AC to DC current.

11-08-2018, 02:03 PM	#9
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,436	Re: De-magnetize I used to magnaflux before I sold the machine. I still have the big AC demag coil and a gauss meter though. A lot of stuff I get back from the NDT shop is still magnetic so I run it through the coil. There are two ways to magnetize parts depending on the direction of magnetism you need. Shooting a strong DC current through the ends of a shaft will give the shaft a circular magnetism. Wrapping a coil around the shaft and hitting the coil with a strong DC current will induce a longitudinal magnetism through the shaft with north on one end and south on the other. In any case the shaft has to be draw through an active AC coil at a slow pace to completely demagnetize it.

11-08-2018, 05:30 PM	#11
Ronnie Senior Member Join Date: May 2010 Location: Canada Where it snows Posts: 2,058	Re: De-magnetize Stop reinventing the wheel just do as this fellow does and no worries.I do knife sharpening and some customers knives are really magnetized and they get done like this all the time. Nothing to do with heat. https://www.hobby-machinist.com/thre...netizer.65952/ R

11-08-2018, 06:20 PM	#13
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,436	Re: De-magnetize Many of the soldering guns are induction type so they have a small AC coil. If I hold a shaft in the coil of my demagnetiser, it will heat up too. This old coil is 220 volt so it doesn't take much on small parts. It takes a bit more to demag a crankshaft though. Sometimes I have to pass it through several times or edge the long side up close to the coil & move it side to side a bit. A person definitely doesn't want any residual magnetism in something with any bearing journals. I check every part I send out just to make sure. I always get a kick out of letting my NDT guy know too. It's usually some new kid he hires that screws the pooch. We all learn by mistakes and I've made my share.

11-08-2018, 08:39 PM	#14
woodiejon Junior Member Join Date: May 2010 Posts: 26	Re: De-magnetize Just move on its no big deal.

11-08-2018, 11:15 PM	#15
fordor41 Senior Member Join Date: Oct 2011 Location: elmira,ny Posts: 1,517	Re: De-magnetize some times you can hit it on a piece of metal a few times if it's not too magnetized

11-13-2018, 12:14 AM	#16
ford35lh Senior Member Join Date: May 2010 Location: Upstate; The Real New York Posts: 444	Re: De-magnetize I was looking around for my Weller soldering gun when I saw my armature growler buried on a bench. (Blink) thats a light going on! Plugged it in and held on tight. Two passes and the file is back to normal again. I still want to play with the soldering gun field on one of the coming long nights.

11-13-2018, 08:28 AM	#17
Red98 Member Join Date: Nov 2018 Posts: 60	Demagnetizing Nicholson Files Subject the magnetized article to a strong AC field such as a Weller soldering gun open frame transformer. Gradually reduce the field by reducing the gun's input voltage to naught. Either use a variac, or gradually increase the distance by slowly moving the article away from the field so its a good 3-4 feet away from the field. Test by carefully subjecting the file to that vintage Patek Philippe watch your wife just inherited from her favorite grandaddy and see if you can dislodge the balance wheel. Then accidentally click the solder gun next to the watch. Time to get some some exercise.