De Magnetising

[rikrobson]

I was watching a you tube video the other day when someone was setting up something or other and as an aside the guy sad look this de magnetises stuff and put a screwdriver in a device or a loop and said ' look this demagneises as well' and all the swarf dropped of the screwdriver.

The trouble is I've got some external jaws and one is magnetic. I just need to de magnetisit and I cant remember which video it was or who it was by. Might have been about VFDs.

If the Jaws fit my chck that is. bought them cheap off ebay and thing they are about right size. I'll find out when I get Home.

Otherwise its selling magnetic Jaws on ebay.

 

[Brad93]

Cromwell tools sell a demagnetiser

 

[rtbcomp]

Google "degausser" you might get some idea how to build one.

Basically they're just a coil with AC current running in it and as you slowly withdraw the item to be degaussed the weakening and alternating magnetic field de-magetises it.

 

[Wendelspanswick]

You can try rapping it hard on a flat surface to try and disrupt the direction of the electron??? flow.

 

[Paul.]

We used to use our old arc welders to demagnetise drill bits, a few turns of the welder electrode lead round the drill put it on about 100 amps and short an electrode to the bench for a few seconds, bear in mind this was on factory power supplies using proper oil cooled AC welders, on a home power supply you would probably blow a fuse or trip, don't try it with an inverter

 

[graffian]

I was going to make one with an old microwave transformer, something to do with the transformer.

 

[I'm getting on a bit]

I've got an eclipse one working and a spare one in bits.

Bought at auction , NOT EBAY

 

[Mr Fro]

'it it wi' 'ammer.

You need to disrupt the domains - you could adapt an old style power-pack or charger if you isolate the AC side of things.

 

[rikrobson]

It was defiately a coil of some description. The annoying thing is I seem to remember thinking, that was a good idea and had the stuff to hand in the W/Shop.

But ive just got a mental picture of the swarf dropping off the screwdriver..

I'll need to look back over the history of the last few weeks.

 

[rtbcomp]

You should be able to wind a coil and limit the current with a bulb.

 

[rikrobson]

Yeah I know the theory, but I'm just annoyed at forgetting the youtube item.

Anyway it's all irrelevant now as the jaws don't fit the Chuck. The size is spot on but the scroll is a different coarse pitch that the 5" Pratt I have. Its possible ones metric and the other is imperial.

I'll clean them up and stick them on ebay. They were cheap anyway and has quite a bit of surface rust. It was worth a punt for the money. I just need to find Some external jaws for a 5" Pratt.

 

[Bill Edwards]

We used to use our old arc welders to demagnetise drill bits, a few turns of the welder electrode lead round the drill put it on about 100 amps and short an electrode to the bench for a few seconds, bear in mind this was on factory power supplies using proper oil cooled AC welders, on a home power supply you would probably blow a fuse or trip, don't try it with an inverter

That's very handy to know, I'll try that with my square which seems to attract horrific quantities of grinding dust.

 

[daleyd]

These are the type you can buy to do screwdrivers and suchlike. I used to have one (Gone walkabout off a job a few years back though)and it got used quite a bit for fiddly screws on thermocouples etc.

http://www.screwfix.com/p/wiha-magnetiser-demagnetiser/4841k?_requestid=247330

 

[MattF]

An old degaussing wand would work. There should be a good few of those knocking about second hand, now that CRT gear is outdated.

I'm guessing this is the type of thing you were watching on Youtube?

 

[rikrobson]

something like that but it wasn't about de magnetizing it was an aside in another subject

 

[the snooper]

I used to de magnetise the old crt tv screens with an instant heat soldering gun, a quick run round the screen did the trick

 

[rikrobson]

Well done The Snooper, that was it. An instant Soldering iron.

My Dad had one when I was a kit. Built my First Model railway with it. used to get quite hot and heavy.

So thanks, for that, but I don't have one and the chuck jaws are the wrong scroll pitch

But hey ho at least i remember how to do it now. I might just make a de gausing wand. I've plenty od small transformers lying around.

 

[MattF]

My Dad had one when I was a kit.

Did your dad have to assemble you then?

 

[rikrobson]

Did your dad have to assemble you then?

Nope came fully assembled. It's just we are rabbits. Got brothers and sisters called floppy mossy cotton tail and Peter.

That or I can't type

 

[rtbcomp]

You used to able to get degaussing wands for tape heads on reel to reel tape recorders.