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View Full Version : Rare Earth Magnets & Welding

renolaw
05-11-2009, 12:47 PM
Was finishing up a trailer project yesterday. I have several rare earth magnets i use to help position small parts, gussets, etc. Used the magnet to hold the piece in place and tacked it no problem. then went back to do finish welds above the magnet and all i got was splatter! Gas was running and no obstructions. Wire feeding properly. Heat/wire speed all in order. WTF???

Removed the magnet from behind the work and it burns just fine. I see in many larger shops use of magnets to hold work, etc., but I never had a rare earth magnet interfere with welding. I regularly use those 45/90 degree magnets to hold work, but this time maybe the super-strong field of the rare earth fuks up the welding energy?

Is there something i missed ? Searched here and via Google w/ no clear answer.


Ideas?

mb
JeepinPete
05-11-2009, 12:52 PM
You guessed it. The magnetic field of the rare earth magnets was deflecting/repelling the arc, and thus the molten metal from the wire. I do wonder if it would have welded normal if you flipped the magnet over, which would have changed the polarity the arc saw?

Pete
renolaw
05-11-2009, 01:29 PM
You guessed it. The magnetic field of the rare earth magnets was deflecting/repelling the arc, and thus the molten metal from the wire. I do wonder if it would have welded normal if you flipped the magnet over, which would have changed the polarity the arc saw?

Pete

tnx, i'll give that a try. the rare earth magnets work really good to hold small pieces but it did not occur to me to move it 180 degrees. hummm.... gotta go experiment!
BumpyDodge
05-12-2009, 01:54 AM
search "Arc blow" on Google - you'll find more info.
rockmup
05-12-2009, 04:29 PM
I've had that happen with reg. jig magnets too.
DavidVanVorous
05-12-2009, 04:58 PM
SOP, Im sitting in an office with a coating machine just outside that uses that exact technique to move the plasma from the arc source creating said plasma into and onto the parts being coated. In my case I use electromagnets with a whole lot lower field strength than whats created by a typical Neo-Iron (rare earth) permanent magnet...yes we use "Blue" welders as a current sorce for the arc sources... ;)

D.
stimie
05-14-2009, 08:48 PM
I've had welders working for me on pipeline that had to use magnets to pull the weld in. It was on older pipe that had been in the ground for sometime.