15 hours ago, Scott NC said:

I wouldn't use one on a surface grinder.

I do about everyday. All of our surface grinders at work have magnetic chucks like that. 

Das, the magnetic feild should release when "off", we use a soft bristled brush to clean dust off with. Also with any magnet the contour of the piece you are working will matter. If you put a 1/2" ball bearing on a magnet it is much more easy to pull off than a 1/2" piece of flat bar. That is the reason the pliers will pull off easier.  From what you describe it sounds just about as strong as any i have used. Even at work sometimes i have to lay pieces of flat bar to brace what ever it is i am grinding. 

Also, yes as a machinist i would have the same reaction watching you weld on one of those as i would as a blacksmith watching you use a cutting torch on an anvil. But i also have to say nice looking "outside the box" at what can aid you in your endeavors. 

  I was talking about the one Buzzkill described.  I wasn't too clear.  I realize surface grinders use magnetic chucks.  However the only surface grinder I have ever used was at community college, 30 or so years ago, in machinist class as an elective for a welding degree.  Sorry for any confusion.

Thanks Billy. I appreciate the info. 

The cutting torch on anvil analogy might be a bit harsh but I do understand. Think of it as at least it's a cheap chinese anvil instead of a beautiful Refflinghaus anvil.  

I'm thinking I will see how it works with a very thin sheet of metal over it to protect from weld spatter. If nothing else keep it sprayed with anti spatter spray. 

 

Sheet metal will most likely block the magnetic field. I’d try a nonferrous material, but it would need to be as thin as possible. The strength of the magnetic field drops dramatically with distance. Anti-spatter spray may be the best option.

Keep it fun,

David

55 minutes ago, Goods said:

I’d try a nonferrous material, but it would need to be as thin as possible.

Maybe a couple of sheets of aluminum foil?

The magnetic field from the welding current could possibly damage (demagnetize) the chuck. I’d avoid grounding through the chuck, and try to set up the ground clamp to keep current as far from the chuck as possible. 

4 hours ago, Scott NC said:

I was talking about the one Buzzkill described.  I wasn't too clear.  I realize surface grinders use magnetic chucks.

I'm fairly sure that if I tried to use the one I got on a surface grinder the stock would slowly drift on the chuck while in contact with the grinding wheel.  I can slide the piece of angle stock I mentioned before along the length of the chuck with a little effort.  I'll be contacting the manufacturer, but if I have to pay much for shipping to send it back to them there's a good chance I'll take it apart instead. 

There was a magnetic chuck on the surface grinder in my high school metal shop and it'd been there a while, I graduated June, 1970. Nothing slipped nor could any kid in the class lift a piece off it when engaged. It was built into the table on the grinder and I don't recall the surface grinder's make. 

The wheel(s) on the grinder didn't apply much force against the work, even if you stacked a couple few. Surface grinders aren't meant to hog steel off like a horizontal mill. High frequency vibration is a factor on the other hand. IIRC surface area on the plate made more difference than thickness but that was about 54 years ago that I used one.

I think I'll have to start keeping my eyes open for a magnetic chuck, hopefully in the 2nd. hand stream. I wonder if putting two together face to face would make a magnetic repeller field. . . 

Frosty The Lucky.

29 minutes ago, Frosty said:

I think I'll have to start keeping my eyes open for a magnetic chuck, hopefully in the 2nd. hand stream

They show up frequently on the HGR website. There are four there right now, plus half a dozen machines with them already mounted.

The problem for me is the HGR site cancelled my subscription maybe for lack of sales but when I try to resubscribe it says I'm already a member and can't have two. I haven't tried in a while so maybe I'll see what they say now. 

Does your magnetic chuck leave residual magnetism in the work?

Frosty The Lucky.

I didn't notice any.  I will keep an eye out for any after tacking some pieces on it. 

Tho when I went to pick up the cut nails they fooled me for a second because they were slightly sticking. I had forgot that a Lot of cut nails I have used are slightly magnetic. Not sure why, it might happen in the process of their manufacture. 

Hmmmm, I haven't gotten to searching for a diagram of how they work but right now my ignorance voice is suggesting the magnets in the chuck might be alternating + - and countering any magnetizing that might be going on. 

I can think of two quick tests. Lay a piece of small gage steel rod, etc. on the chuck leave it for a while then run one end through iron filings.

Orrrr, stand a small dia. rod on end on the chuck. If you hold it by the end with finger tips is should want to stick to one magnet. Then check the filings after a while. If isolating one magnet in the chuck magnetizes the rod it would indicate . . . to ME the magnets in the chuck must be reversed in series to reverse the effects.

An AC electromagnet doesn't magnetize what it picks up because polarity reverses 60/sec. Demagnetizing yokes use AC to do the same thing.

Hmmmm, I think rolling a bearing ball across the chuck while it's ON would stop the bearing on one magnet and might magnetize it in a little time. 

Now I'm REALLY wanting one to play with!

Frosty The Lucky.

 

We demag all the parts we surface grind with magnetic chucks. The parts always pick up some magnetism and that little bit of magnetism is really bad in stamping dies. I would be surprised if your parts don’t see at least a little, but I wouldn’t expect it to cause you any trouble.

Keep it fun

David

Thanks David, that answers my question well enough for what I need. While I was looking at magnetic chucks on HGR surplus site they listed an AC magnetic chuck which shouldn't magnetize things. Any thoughts for you guys?

Frosty The Lucky.

11 hours ago, JHCC said:

Maybe a couple of sheets of aluminum foil?

That was going to be my suggestion, a sheet of heavy duty aluminum foil.

 

I can't control the wind, all I can do is adjust my sail’s.
Semper Paratus

 

Semper Paratus

 

6 hours ago, Frosty said:

they listed an AC magnetic chuck which shouldn't magnetize things.

I’m assuming that AC is the input, not the output. 

How is the welding going on the magnetic chuck? 

A magnet can interfer with the weld and can pull your arcstrike. Can make it challanging for tacking up small parts.

It was listed as an AC magnetic chuck and  not magnetizing iron and steel is a pretty good reason to use AC magnets in tools like a chuck. I also didn't see a switch for polarity in the pic, just on/off.

No telling for sure without having the specs available or plugging it in and trying it out.

Frosty The Lucky.

This is working out well for the first try. Tacking, wire wheel and grinding welds. 

only human error on the bottom of the cross being off. 

  I'm glad it's working well for you so far.  I have some questions for you but think I will wait until you have used it more to ask.  

Sure, no problem. 

MODE NOTE: The discussion of anti-spatter spray has been moved to its own thread.

16 minutes ago, Mod34 said:

MODE NOTE: The discussion of anti-spatter spray has been moved to its own thread.

You might want to link it here, anti spatter spray is directly related to the magnetic chuck thread, isn't it? It is important to preserving a valuable tool, no?

Frosty The Lucky.

Its ok Frosty. 

Here, for those interested in weld spatter control or prevention of it sticking look up the thread  "Question about controlling spatter". There done. 

One observation tonight is that on this brand/model, the face is soft. The face was scratched by moving the stock around haphazardly.  So if you want pristine, don't just half un magnetized  what you are working on it to flip and turn. I guess take your time to properly move the stock. 

Still works fine and isn't an issue for my use.  For me, this thing is going to go through the ringer of a hard, well used life. 

I was just thinking a shot of anti spatter spray would help preserve the chuck's face when welding.

Frosty The Lucky.