How would you guys go about demagnetizing an anvil?   I 'm pretty sure I have read somewhere that when welding wrap a lead around a corner of whats being welded on and that prevents magnetic build up for lack of a better term.  If so, would wrapping a lead around the anvil and laying a short bead on the bottom work?   From what I understand a batch of anvils has quite a magnetic field most likely from being Blanchard ground. 

 

Any thoughts and ideas?

 

 

You may not even need to weld on one. In WWII they used to "wipe" ships with electrically charged leads to remove magnetism and avoid issues with magnetic mines.. The original tests were done on a steel lighter using welders at the ship yard. High amps were used. I'd try setting your welder as high as it would go and running a bead while someone wiped down the anvil with the welding lead and see if that worked.

 

I can't locate any detailed info right now on exactly how the cables were powered, AC vs DC etc, and all the info I'm finding shows really high amps used to wipe full size ship hulls, like 2000 amps. I do know from reading about the original experiment that it was successful on a small scale in the original tests and I doubt at the time they had access to really high amp welders.

I repair anvils a lot & not had a problem in that area ! just weld it with right ROD !!

Guess these ones came from the foundry this way.  He's looking at options,  figured I might come up with an easier fix than sending them all back for a reheat treat.  And it might get my anvil shipped a little sooner.  :)  He tried dropping one from 10'  off the forklift,  guess that didn't work.  found a few links on degaussing ships and pipes all interesting reads.

Basically you need an AC electromagnet. The AC will switch the north-southoles of the magnet 60 times per second. You then slowly move this over the magnetized area or even better would be to pass the anvil thru the center of the coils. This will rescramble the north-south elements of the anvil.

Wrapping DC lead around a piece of steel is how you magnetize it---AC to demagnetize it!

I know this may be an ignorant question but why would a magnetized anvil be a bad thing?

Guess these ones came from the foundry this way.  He's looking at options,  figured I might come up with an easier fix than sending them all back for a reheat treat.  And it might get my anvil shipped a little sooner.  :)  He tried dropping one from 10'  off the forklift,  guess that didn't work.  found a few links on degaussing ships and pipes all interesting reads.

 

Dogsoldat, You must be talking about a Fontanini anvil.  I've been talking to Steve about that.  He tried dropping it while I tried another route.  My Fontanini came magnetized.  I just successfully de-magnetized it.  At work we have a Blachard grinder with a 36" magnetic chuck.  We put the anvil on it face down and ran it through a few cycles.  It took 7 cycles and some creative positioning (to get the side shelf to cross as many rings as possible) to get the job done.

 

I am interested in the other posters' responses about wiping it with a welding lead while welding.  I don't know if any of that would work, but someone please try it and post your results!

 

And Eseemann, a magnetic anvil is a royal pain!  Think about it.  Ever see one of those arrow magnets after you grind near it for awhile?  It's hairy with grinding dust.  Now imagine you're working at your anvil.  Scale is falling off and collecting on your anvil.  You go to wipe the scale off your anvil (so you don't mar your work or press scale into your work which flake off sometime after it's painted and installed in your customer's home, taking paint with it) and it just slides all around.  It doesn't come off.  My $0.02.  (WHY IS THERE NO CENT SYMBOL ON KEYBOARDS?!!!)

I found this which was interesting:  
 
 
You need to create a solenoid. Get acquainted with Lenz's law and a few other things pertaining to magnetism (any A-Level physics book will contain those things).
Just take copper wire, and coil it around a paper tube of the diameter you need. You then need an alternating current source, or alternating movement.

Let's say you have a 9V battery attached to a coil wrapped around a paper tube (use a resistor in series with this or prepare for fire!).

You want to demagnetize a nail. You can use a constant DC current and move the nail in and out of the paper tube to simulate alternating magnetic fields, or you can provide alternating current. That, is as simple as using a "push to make" or "push to break" switch in the circuit, placing the nail in the paper tube and attempting to see how long it takes to contract arthritis.

Either way, you want the magnetic "grains" to line themselves up uniformly, for a magnetised object, and to demagnetise, you need to throw them out of order.
Read more: http://www.physicsforums.com 
 
Perhaps the "wiping" people are talking about is enough to "simulate alternating magnetic fields" as in the excerpt above.  Or, as it also says above, "you can provide alternating current".
 
In any event, I would like to see if wiping the anvil with current would do it.
  
 
PLEASE do not  drop back ground colors in behind your text, it makes it very hard to read on some screens and is a royal pain to edit out

Rick,
 
 
I cannot find words to think about how uncomfortable, messy and dangerous working on a self-coating/non-stick anvil would be. I can see that setting your work on a 1/10 of a mm of scale would be like graphite packing lubricant so that when you give the steel a good hit the steel is more likely to skid off in a random direction than not. Not to mention that you can never really clean it off, it sounds like the yellow pine pollen in Florida.
 
Yup, I do see a magnetic anvil, no matter how neat it sounds, is a bad thing.

We used to demagnetize drill casing when we ran the magnaflux yoke over it looking for damage. We weren't trying to demagnetize it but the yoke is an AC electromagnet and it did it as we checked.

 

Just wrap one of your welding leads around the anvil a couple times and do some welding. NOT on the anvil, the AC current in the leads will do the job with it's electromagnetic field (Induction currents/fields). I used to just toss any annoyingly magnetized tool in the loops of lead when I was welding. On top of the pile, nested in a roll laying on the floor, on a pile of lead or in the loops where the leads hang on the welder. Didn't matter, demagnetized everything. Occasionally one of the guys would annoy me enough to toss his magnetized screwdriver on a coil. Kills a good compass almost instantly, don't ask me how I know.

 

Frosty The Lucky.

make sure the output of your welder is AC and not DC

On 6/13/2014 at 4:11 PM, the iron dwarf said:

make sure the output of your welder is AC and not DC

Right! I got all involved and forgot the most important part. <sigh>

Thanks for the backup.

Frosty The Lucky.

You guessed it Rick. Guess the cats pretty much out of the bag now... splurged with my tax money to buy a new anvil. Just a matter of getting it shipped and picked up...


http://www.vansairforce.com/community/showthread.php?t=40673

post #7 on this thread recommends wrapping a trouble light cord around the object to degauss. higher the wattage the better. and just leave it over night

I see an good justification for an electric smoker. That way you can wrap the heavy extension cord around the anvil and not waste power since after a few hours there will be brisket. I have other lines of thought to rationalize a gas grill and wood smoker. Smoked beef/pork/chicken needs no reason!   

I just bought a new anvil and it is magnetized as well.. I guess I'll try the trouble light technique tonight..

So I'm guessing that the degaussing wands we used to use for audiophile equipment won't do...

I just tried a degaussing  tool we use to demagnetize landing gear after lightning strikes and it didn't work..its a 242 pounder.. 

Yes I do some thing similar to Frosty, I used to have to go to the local aluminum smelter and after you came back every thing was magnetised which seemed to make any needles from the grinder or die grinders stick out at right angles and stick into your fingers and pulling out a string of spanners out of your toolbox gets old real fast. But anyway my method is to loop up your earth lead of your AC welder into a circle big enough to pass the said items through conect the earth directly to the hand piece terminal set the welder at a fairly high amperage turn it on and pass the items backwards and fowards a few times and it will be done

 

 

 

 

I just talked to my anvil supplier and he told me it's from the milling process and that it will loose magnetism the more I use it..he says it shouldn't take long.. I think I'll try the welder technique. 

As steel takes on the magnetic field of the earth as it cools through the curie point I would guess it was from that rather than milling---UNLESS they were using a magnetic chuck...

The milling is what he thinks it's from and I don't know if he has spoken with the foundry about this or not.. either way and maybe both it's a big magnet right now..

How are they lifting those things?  By magnet and crane?

Magnetism comes from the dipoles in the metal being organised all in one direction. You can desorganise them using an alternate current or by ... striking it with a hammer. 

In other words, use it as intended and all should be fine after a bit of pounding

Well I fully intend to put it thru it's paces for the next few days.. hopefully it will release the magnetism.. it's a beautiful anvil..242 pound papa rhino.