Chinese clone demagnetizers

[HectorLooi]

1 hour ago, VWatchie said:

The cheap blue Chinese demagnetise-rs are useless if you feed them the wrong voltage (> 110 V), and even so, they don't work very well. The one I got when I was new worked so poorly that it drove me nuts.

Maybe you got a badly wired one like the one I had.

Can you feel the metal object vibrating when you press the red button? 

[Neverenoughwatches]

12 minutes ago, HectorLooi said:

Maybe you got a badly wired one like the one I had.

Can you feel the metal object vibrating when you press the red button? 

With anything of any size to demag i need to hold onto it to stop it sticking fast. If i put a balance or part in a container it vibrates like crazy.

[Jon]

The only reason I bought the Eclipse second hand for 30 quid is because the Chinese blue one I was using lasted about five minutes before I threw it in the bin in frustration that nothing was demagnetising. Maybe I got a dud. The Chinese/AliExpress demagnetisers look good for the money!

[mikepilk]

1 hour ago, Jon said:

The only reason I bought the Eclipse second hand for 30 quid is because the Chinese blue one I was using lasted about five minutes before I threw it in the bin in frustration that nothing was demagnetising.

Sounds like you and @VWatchie were unlucky. Mine has been running on 230V UK for years  ( it's been 230V for many years @Neverenoughwatches, not 240V).  Though I have had to re-solder some wires.

When I buy cheap Chinese electrical components I often take them apart to check they're not going to kill me. Since the demagnetiser, I bought a cheap fish tank heater for my plating set up. Plugged in, big flash and smell of burning. Deader.
So I bought a cheap cup heater plate. Exactly the same - flash, bang, wallop. 

 

 

Edited May 18, 2024 by mikepilk

[Neverenoughwatches]

28 minutes ago, mikepilk said:

it's been 230V for many years @Neverenoughwatches, not 240V).  

That has become habit to quote since learning about electricity as a kid. I'm sure even my old school sparky (74) still uses divisions of 240v to work out current draw and fuse ratings. Uk  Rating on my travel kettle averages out at 230volts

[tomh207]

That discrepancy is because it is nominally 230v, if you’re next door to the power station you will be closer to 240v but if out in the boondocks the alledged minimu gaurantee is supposed to be 220v (don’t tell folks in Dumfrieshire that they’ll get all jealous and up in arms)

 

Tom

[Neverenoughwatches]

2 hours ago, mikepilk said:

Sounds like you and @VWatchie were unlucky. Mine has been running on 230V UK for years  ( it's been 230V for many years @Neverenoughwatches, not 240V).  Though I have had to re-solder some wires.

When I buy cheap Chinese electrical components I often take them apart to check they're not going to kill me. Since the demagnetiser, I bought a cheap fish tank heater for my plating set up. Plugged in, big flash and smell of burning. Deader.
So I bought a cheap cup heater plate. Exactly the same - flash, bang, wallop. 

 

 

The wax melt heaters work well to about 80° C. The Yankee Candle ones are well made.

[Levine98]

On 5/18/2024 at 6:53 AM, Neverenoughwatches said:

Maybe you had a bad one H, the cheap blue one i use has been fine for nearly 3 years now. It demags enough to stop the tiniest of screws sticking to the carbon steel tweezers i use. If it were to fail at some point in the future i very  probably would go up a level of device just because. 

My $12 blue one seems to work well enough for movements out of case. However for  tools with greater mass, such as my small and large anvils which are highly magnetized the blue unit is useless.
 

For whatever reason, my high current K&D donut unit just doesn’t seem to work, regardless of my attempts to use it as instructed in this thread (magnetizes stuff fine so I know it is energized).

 

[Neverenoughwatches]

1 minute ago, Levine98 said:

My $12 blue one seems to work well enough for movements out of case. However for  tools with greater mass, such as my small and large anvils which are highly magnetized the blue unit is useless.
 

For whatever reason, my high current K&D donut unit just doesn’t seem to work, regardless of my attempts to use it as instructed in this thread (magnetizes stuff fine so I know it is energized).

 

 

The 110v supply could be problem with the blue one. Have you tried moving the piece to demag through different orientations manually as its drawn away ?

7 minutes ago, Neverenoughwatches said:

The 110v supply could be problem with the blue one. Have you tried moving the piece to demag through different orientations manually as its drawn away ?

As Nev quoted the magnetic fields of the demag have to overcome those of the steel. 

[Levine98]

15 minutes ago, Neverenoughwatches said:

The 110v supply could be problem with the blue one. Have you tried moving the piece to demag through different orientations manually as its drawn away ?

As Nev quoted the magnetic fields of the demag have to overcome those of the steel. 

I’ve tried everything using both my blue and donut demag units.  I’ve even tried beating them with a steel hammer
 

im now trying heating them over gas flame — if that doesn’t work …..

[VWatchie]

10 hours ago, Levine98 said:

im now trying heating them over gas flame — if that doesn’t work …..

 

Isn't it funny where watch repair can take us!? 

[tomh207]

5 minutes ago, VWatchie said:

Isn't it funny where watch repair can take us!? 

It certainly is around here!

[Neverenoughwatches]

Will barby get hot enough ? the heat needs to reach around 800°C to disrupt the magnetism. You can always chuck a couple of burgers on it though.

[HectorLooi]

After that the staking blocks would have lost their hardness and would only be good for paperweights. 

[Jon]

4 hours ago, Neverenoughwatches said:

Will barby get hot enough ? the heat needs to reach around 800°C to disrupt the magnetism. You can always chuck a couple of burgers on it though.

Funnily enough, when heating iron or what watchmakers use for making tools which is 'tool steel', or what is also known as 'high carbon steel', as it has a carbon content between about 0.06 to 1.6% carbon content, (but don't quote me on those percentages!) and can be hardened and tempered, when the steel reaches a cherry red, around about 1450 to 1500 degrees Fahrenheit it becomes non-magnetic, so if you placed a magnetic close to or on it there would be no effect at all. I believe it is the steel/iron turning to austenite from martensite, if I remember what I read in an old metallurgy book I picked up in a car boot sale; It's a bit of an esoteric read! In years gone by, cattle bone was used to encase the small piece of steel to be hardened and tempered, so the carbon from the bone was soaked up by the steel when heated for several hours at a particular temperature, in effect 'case-hardening' the steel. It's amazing what we came up with many years ago. We humans are very inventive, yet very destructive.

[Levine98]

4 hours ago, Neverenoughwatches said:

Will barby get hot enough ? the heat needs to reach around 800°C to disrupt the magnetism. You can always chuck a couple of burgers on it though.

No, only about 1000f. But i took pleasure in roasting these annoyingly magnetized parts

[Neverenoughwatches]

7 minutes ago, Jon said:

Funnily enough, when heating iron or what watchmakers use for making tools which is 'tool steel', or what is also known as 'high carbon steel', as it has a carbon content between about 0.06 to 1.6% carbon content, (but don't quote me on those percentages!) and can be hardened and tempered, when the steel reaches a cherry red, around about 1450 to 1500 degrees Fahrenheit it becomes non-magnetic, so if you placed a magnetic close to or on it there would be no effect at all. I believe it is the steel/iron turning to austenite from martensite, if I remember what I read in an old metallurgy book I picked up in a car boot sale; It's a bit of an esoteric read! In years gone by, cattle bone was used to encase the small piece of steel to be hardened and tempered, so the carbon from the bone was soaked up by the steel when heated for several hours at a particular temperature, in effect 'case-hardening' the steel. It's amazing what we came up with many years ago. We humans are very inventive, yet very destructive.

I remember dipping cherry steel into some kind of carbon powder at school to case harden it. And watched a video about annealing steel a few months ago  when making my setting lever. The guy used a magnet to determine the steel's core temperature .

5 minutes ago, Levine98 said:

No, only about 1000f. But i took pleasure in roasting these annoyingly magnetized parts

Get a blow torch on them or you could really flip and use an oxy torch and melt those suckers.

[VWatchie]

19 hours ago, Jon said:

We humans are very inventive, yet very destructive.

I agree, it's so sad how we chose to use our inventive abilities.

I saw this video about what would happen if a single Russian nuclear bomb detonated in New York and it scared the living daylights out of me. Everyone should see it, especially our politicians who I'm not sure are aware of the destructive power of nuclear weapons. They don't seem to worry much. Perhaps they think they will be safe in their bunkers.

In the video, it is mentioned that just a single intercontinental ballistic missile "SS-18 Satan" corresponds to over 530 Hiroshima bombs. It's all beyond comprehension. Humanity and civilisation wouldn't stand a chance.

Sorry for going OT again!

Edited May 21, 2024 by VWatchie