Welding Tips and Tricks

Howdy,

Had a magtab drop a piece of steel today. Just quit on me.. I assume the heat caused it to give out.

Has anyone else here had any issues like this before?? If so please share.

How hot did the Mag Tab get?

I don't own any myself but have some experience with magnets and heat. In the past I had to use heat to soften the special adhesive holding the magnets into the flywheel of one of my race bikes. Beyond a certain temperature - known as 'Curie Temperature' - magnets lose their magnetism. Although I was as cautious as I could be while using my gas torch to heat the flywheel (shielding, heat sinks) there is no doubt the magnets became quite hot.

If I compare an identical flywheel magnet that has never been heated to one of the magnets that I have removed using heat, the magnet that was heated seems about half as strong. My non-scientific test method is to pick up chunks of steel. The heat affected magnet will only lift half as much before letting go.

Wouldn't be surprised if your Mag Tabs have perhaps suffered a similar fate.




Kym

If you heat steel to red it will lose most if not all of it's magnetic properties.
I forget the the particulars of the relationship to heat buildup and magnetism loss. I would be very careful attempting to move a heavy chunk if it was heated up a lot. I do believe it has to do with the crystalline structure of the steel and the particular alloying elements.

Well I ran a weld about 3 inches long and the magnet let go... exact temperature only God knows ..

And yes the way to harden steel is to heat it to red or better where it passes the nonmagnetic point and then quenching it in some sort of quenching solution to refine the crystalline structures.
I just never thought I could mess the magnet up by too much heat beibg transfered from the magnet.

How close to the magnet were you welding?


Kym

NoStrangeFireHere wrote:Well I ran a weld about 3 inches long and the magnet let go... exact temperature only God knows ..

And yes the way to harden steel is to heat it to red or better where it passes the nonmagnetic point and then quenching it in some sort of quenching solution to refine the crystalline structures.
I just never thought I could mess the magnet up by too much heat beibg transfered from the magnet.

Magnets are made for positioning(tacking). Clamps and vices are to use while welding.Time for a new magnet.

Too close lol, and yes tine for a new magnet. I wonder if I can fix the magnet in some way.

I mean in theory if it can lose its magnetism then it should be able to gain it some way.

Sometimes you just have to let go


Sent from my iPhone using Tapatalk

NoStrangeFireHere wrote:Too close lol, and yes tine for a new magnet. I wonder if I can fix the magnet in some way.

I mean in theory if it can lose its magnetism then it should be able to gain it some way.

You can try. Theoretically there are electrical methods by which to re-magnetise your magnets, but it all became a little too complex for me.

However....when I tested my weakened flywheel magnets, they charged adequately to run my bike's electrics. What's more, they appear to be charging more strongly the more I use the bike. Perhaps all that whizzing around the coil is giving them new life?


Kym