Electric Demagnitizers

REK Knives

REK Knives

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Knifemaker / Craftsman / Service Provider
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Hey guys. So I've got a vintage electric pass - through type demagnetizer but I did leave it on one time too long and it started smoking. That being said it still seems to work as I can feel the magnetic field like normal when I turn it on.

The problem is I'm still getting some very light residual magnetism in the blade... Like when I sharpen all the steel dust is attracted to the blade.

For others that have one, I was wondering if you have this issue with your demagnetizer? (regardless of what type - I'm trying to decide if I need a new one and which one to get)

i-3zPQtdQ-X4.jpg


It's still barely strong enough to pick up a detent ball
i-BBXSc7Z-X4.jpg


Here's a pick of my demagnetizer
i-7vrMKCD-X4.jpg
 
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I can't comment on the ring type ones like you have but I've been using a cheap Shars plate-type demagnetizer in my shop for years and I couldn't imagine not having one. It's not the most powerful model but it's largely been sufficient for my uses so far.
 
To demagnetize, while holding the blade in the center of the demagnetizer, turn it on and slowly draw the blade out of the demagnetizer till the blade tip is a few inches away from the demagnetizer, then turn it off. The blade should be demagnetized.
 
Nope, after a few seconds mine won’t pick up dust or shavings. My SGA turns my knives into pretty powerful magnets too.

I got one of the cheap ones on Amazon, something like this:

One thing I found that helps is after it’s demagnetized, I smack it on my wooden bench a few times and that gets the last bit out. Don’t know the science on that one but it helps haha!
 
Place the blade all the way through with the ricasso on the other side. Hold the ON button/switch down and slowly draw the blade back through the de-magnetizer until several inches away. Release the button/switch.

If you do what you are saying, it will magnetize the blade.
 
Cliff Carter Knives said:
Nope, after a few seconds mine won’t pick up dust or shavings. My SGA turns my knives into pretty powerful magnets too.

I got one of the cheap ones on Amazon, something like this:

One thing I found that helps is after it’s demagnetized, I smack it on my wooden bench a few times and that gets the last bit out. Don’t know the science on that one but it helps haha!
Click to expand...

I bought a vintage demagnetizer on ebay. You might still be able to find some good vintage demagnetizers.

Demagnetizer-1a.jpg
 
Cliff Carter Knives said:
Nope, after a few seconds mine won’t pick up dust or shavings. My SGA turns my knives into pretty powerful magnets too.

I got one of the cheap ones on Amazon, something like this:

One thing I found that helps is after it’s demagnetized, I smack it on my wooden bench a few times and that gets the last bit out. Don’t know the science on that one but it helps haha!
Click to expand...

OK then there must be something wrong with mine and it's time for a "new" one! Thanks for confirming.

Stacy E. Apelt - Bladesmith said:
Place the blade all the way through with the ricasso on the other side. Hold the ON button/switch down and slowly draw the blade back through the de-magnetizer until several inches away. Release the button/switch.

If you do what you are saying, it will magnetize the blade.
Click to expand...
Yep that's exactly what I do... So once you demagnetize there should be zero residual correct?
000Robert said:
I bought a vintage demagnetizer on ebay. You might still be able to find some good vintage demagnetizers.

View attachment 1796251
Click to expand...
Yep I saw one of those just earlier today on there, maybe I need to snag it!
 
Stacy E. Apelt - Bladesmith said:
View attachment 1796307That is the same one every watchmaker and jeweler I know uses. I have a couple of them.
Click to expand...

Yep. There is a really nice South Bend for sale. If I could afford to let go of the money, I would buy it. But if it isn't gone tonight I might talk myself into snagging it.
But that's why I bought it - watchmaking was going to be one of my hobbies, but it's just too intricate and kills my back. I've been thinking about selling most of my watchmaking tools and stuff except for the Bulova Accutron tools and meters and stuff.
 
While those vintage South Bend, K&D, and similar units are nice, they don't do anything a cheaper modern Chinese unit can do for half the cost or less.
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When I was a kid we wound them ourselves with "magnet wire".
 
Rapping the blade sharply will really get rid of the magnetism. I use a magnet to hold some of my tools.
It works. You can also hit the magnetized item with a small hammer, etc.
 
Bill DeShivs said:
Rapping the blade sharply will really get rid of the magnetism. I use a magnet to hold some of my tools.
It works. You can also hit the magnetized item with a small hammer, etc.
Click to expand...
Interesting... Well maybe you can tell me what I'm doing wrong here because I've heard that claim for years but it's never once worked for me

 
REK Knives said:
Interesting... Well maybe you can tell me what I'm doing wrong here because I've heard that claim for years but it's never once worked for me

Click to expand...
Maybe your neighbor is a witch or that screwdriver was quenched in the night of the full moon?

Jokes aside, magnetism is pure sorcery for me :)
 
Gravers for hand engraving, especially when used with a pneumatic engraver, magnetize when cutting steel from the impacts. They start grabbing chips. Time for a quick trip across the plate demagnetizer then.

Interesting issue, Josh. I assume the blade won’t collect shavings prior to sharpening? Looks like the magnetizer works pretty well. Like with gravers, could the ‘impact” of the abrasives make some steels magnetic? Sounds unlikely, but…
 
Striking a magnetized object sharply will jostle the electrons around (simplest way to say it). This will dissarange them from the order they were in when magnetized. It will lose most of the magnetism, but not all. It also takes a good hard blow. I wouldn't recommend it for a knife blade. It works fine for tools like screwdrivers and wrenches.
 
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