Building a degausser to counter the dreaded arc blow...
 

Hiya peeps, I'm having a little problem welding up test plates, and its called arc blow.


Basically, its caused by magnetism in the work peice (what you are welding), what happens is, the electrode and the workpeice basically become two magnets with their poles facing each other, the arc doesnt wanna go where it should (the shortest distance between the electrode and the work peice)

heres a good explanation of arc-blow:
http://archive.metalformingmagazine....05/Lincoln.pdf



so basically, I need some sort of a degausser, I found instructions for one online, but it was designed for degaussing monitors, and I am wondering if it has the balls to de-magnetize a 1 inch thick 12x4" steel plate...


anyways, any help would be appreciated..


arc blow sucks :|

perhaps I should have dropped this in tilted knowledge?

Have you followed the tips in the article about reducing arc blow? Beyond that, I recall heating up steel will demagnetize it. Heating up the metal to red hot, and then slowly letting it cool, would demagnetize the metal. It will also soften up the metal, which may or may not be acceptable depending on the requirements. Depending on your facilities, you could feasibly re-harden the softened metal afterwards by heating and quenching.

This link may help as well:
http://www.magwerks.com/documents/No...agnetizing.pdf

yes, I am doing everything in that article to get rid of arc blow, and the steel gets plenty hot when you bevel it with a cutting torch, so I dunno, I'll read that article...

There's a difference between letting it get hot, and heating the entire piece to a constant temperature. You need to get the metal glowing, and then let it slowly temper. This causes the molecular structure to re-arrange itself in a non-polarized manner, which makes the metal nonmagnetic.

Try banging it with a hammer / mini sledge, I remember something about that working too, but YMMV.

Try calling your local welding shop..

guys, this isn;t something any welders really know what to do about, you just kinda deal with it, and stop if it gets too bad....

I'm a student at modern welding school, which from what I have been told by many is second only to Hobart. They don't have any answers, everyone I have talked to in the field has no idea, its not a problem that has been thought about very much :(

Try reversing the polarity of the welding current for just a bit, (or switch to DC as applicable) should do the trick. Make sure your cables are not coiled near the work or bench. This is not common, check your technique.

Borrow or rent a degausser from a TV repair shop. See if it helps.

Technique is to power the degausser and using a circular motion, bring it near the metal and then back off slowly till far enough away. Then remove power.