Degaussing?

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Apr 24, 2013
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I was looking up some degaussing stuff, since making the magnetic chuck for surface grinding. The chuck works wonders, but it's pretty "sticky" & leaves a bit of magnetism in each blade once I use it. I found the great reviews for Enco stuff, only to see they were no longer in existence. Does anyone have a line on an inexpensive degaussing setup for the shop? I don't want to send out a blade to someone that keeps picking up paper clips & filings...

I've looked at the simple magnet types & also some of the desktop stuff. I just want something simple which works & will do blades up to 1.5" X 12" without costing too much. Thanks, tim
 
Does anyone have a line on an inexpensive degaussing setup for the shop?
I've found that one way to of degaussing is to take an ordinary magnet and run it along the spine. If going from handle to tip doesn't work, go the other way (from tip to handle). That's worked for me in the past.
 
Build and electromagnet with a polarity reversing switch. Wiggle the switch back and forth with your blade in the field.
Should work, although I have never tried it...
 
I bought a demagntizer on ali express same brand as I found on ebay and Amazon about half price. And don't kid yourself they're all from china.
 
I use a degaussing (demagnetizing) coil ate work and in the shop. It works great on blades and tools.
 
Thanks guys. Tried the spine-to-tip trick with my big magnet. Now picking up bigger stuff, so I need to send for one here soon.
 
A ferr0-magnetic metal ( iron in the case of a knife blade) becomes magnetized when it sits in a strong magnetic field for a while. It can happen slowly by just sitting for a long time while pointing north-south in the earths magnetic field. It happens quickly when attached to a strong magnet. The iron atoms get teir electrons arranged in the direction of the lines of magnetic flux. When the iron object is removed from the strong field, it retains that arrangemen ... called retained magnetism. The old trick was to strike the object hard or hammer on it to disarrange the alignment. This works a bit, but is hit or miss.

I never understood the often suggested trick of stroking a magnet on a blade to demagnetize it. That is how you magnetize a blade or tool?????

To remove residual magnetism in a blade that has been magnetized, you have to put it in a field where the magnetic flux reverses rapidly. A degaussing coil does that 60 times a second and will demagnetize a blade or tool in a few seconds.
 
You can make a degausser by taking the rotor out of an AC motor and passing the blade between the coils while they are powered up.
I made mine from the fan motor out of a small electric heater. It's ugly but it works.
 
I never understood the often suggested trick of stroking a magnet on a blade to demagnetize it. That is how you magnetize a blade or tool?????
I've wondered this too, but, because it has worked for me in the past, I reasoned that it was because magnets have a (+) and (-) pole.
go the other way (from tip to handle)
I have experienced the magnetism getting stronger after trying this, but was able to eliminate it with further passes, perhaps when it worked, I was also holding the magnet the opposite way? I haven't had to do this enough to pay attention to exactly how I was doing it. I'll pay attention in the future.
 
Yes, AC passing through any coil of consisting of many turns of fine wire will work. One can be made from a bunch of junk box parts and an old degaussing coil from a CRT ( old TV or computer monitor). But with them selling for less than $50, a commercial unit is probably the simplest way to go for anyone not electronical/electrical skilled. In the old days we wound them from magnet wire. It is basically just a big coil or wire.

I'll have to ask my daughter and SIL if the huge roll of magnet wire is still hanging in my old workshop (they live there now). Might be fun to wind a bunch of coils.
 
I ordered one of these & am hoping it works well enough for my needs. I'll let people know how it works in the shop. Should be here at the end of this week, but that may shift into next week with shipping here as it is (slow)...
https://www.ebay.com/itm/171289341881?
 
Just a follow-up on the demagnetizer, it works! Arrived just now, no more paperclips stuck to the blade or blades pointing at each other on the table. It's a light duty machine, but it should work fine for blades & small parts. Thanks for the suggestion Ken.
 
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We do a TON of surface grinding so in turn we do a ton of demagnetizing. We tried the gutted motor and we where not getting the results we wanted. We also did not like that fact that voltage could be exposed to contact with a blade or body part. So we invested in this and it’s been amazing.

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Dang guys, that's some heavy voltage & current to pull, looks like you could do some pretty hefty parts & do them quickly. The small plate on mine (just 110v, not for prolonged use) works very well for knives, no complaints, but for production work I can see where you need the capacity to go up a few steps. Looks like railroad track would be no problem...
 
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