How to remove Scale? or should I?

[StumpXJ]

So, I finally got the top welded onto my little welding/light fabrication cart and needed to ask what is the best way to get the scale off of the steel. Or, do I just leave it on? It is just a piece of 5/16" thick, 25" wide X 37" long steel plate that I welded to the top of my cart. My intention is to leave it 'raw' and have it permanently grounded to my welder so it will be a grounded welding surface, like most any other fabrication table.

I know how to get scale off of steel, just by using a grinding disc/pad etc, however I dont want to have to grind such a large area, and I dont want to scratch up/gouge the table top. Do I just leave the scale on the steel? Is there and easier method to remove it without damaging the top? some type of wire wheel or flapper? (I tried using a couple regular wire wheel, but it didnt have a chance...)

Here is a pic of the cart without the top, I will post one of the new top tomorrow.

Thanks, James

 

[akdiesel]

This is for your safety and may not be related, but I used to work for a wireline company years ago that did service to down hole equipment on oil wells and they had scale build up on gaslift valves. The scale had to be taken off and practice at the time was to wet the scale and use a dust mask. Keeping it wet reduced the chance of making it air born since it had NORM(natural ocuring radioactive material). I would suggest the same practice but I am sure your scale is not radioactive.

 

[dragginbalz]

I know you said you do not want to grind, but a Norton BearTex wheel is by far the best thing I have found to remove scale. It is flexible so it will not dig in and will remove it in a hurry.

You can get them in 4.5" or 7" as well as the 3" roloc, drill mount, etc.

I have a 7" on a grinder and it resurfaces (removes light rust) on my table saw and welding table in a matter of minutes.

 

[StumpXJ]

Thanks for the reply's, I will look into the Norton wheels, I use Norton for cut-off discs and such and they are a good product usually.

I sure hope my table isnt radioactive , but I usually wear a mask when I grind anyway.

Thanks, I didnt think there was any 'secret' to getting this stuff off, just figured I would ask.

~ james

 

[Jack Olsen]

You still might want to ask whether it needs to go. It's a lot of work to get it off, and you're going to face quicker rust issues with shiny steel. To my knowledge, mill scale isn't going to have any negative impact at all on the functionality of a welding surface.

All that said, I used sulfuric acid on my 1" plate table top. I did it only for cosmetic reasons. Details here.

 

[tonydanzah]

what about an air needler?

 

[StumpXJ]

Thank Jack, I appreciate the info. I think I may just leave it on, I have already gotten rid of any 'high' parts with the wire wheels.

~ James

 

[StumpXJ]

what about an air needler?

That would probably work for a small area, but it would take forever to do the whole thing. This stuff is ON there! Its tough to break through it even with a 40 grit sanding disc, then when you do break through the scale, it gouges the steel.

~James

 

[bluesman2a]

I have to agree with Jack on this one, leave it on. As the table gets older, you'll get accumulated welding spatter, tacks for fixtures and the like on it. I typically clean my tables either after or before large projects.

Depending on what's down, you can use a roloc "surface prep disc" or a flap-wheel on a grinder with 80-120 grit. The rolocs will clean/polish a surface without removing much if any material underneath (and they do it fast). They make them in several aggressive/fine profiles and they look like velcro pads. The flap wheel will remove more material, but they do it in more of a polished manner than a regular disc. I use Norton brand wheels for both, you can get them locally at Northern Tools.

 

[OccupantRJ]

That would probably work for a small area, but it would take forever to do the whole thing. This stuff is ON there! Its tough to break through it even with a 40 grit sanding disc, then when you do break through the scale, it gouges the steel.

~James

I use 36 grit on a 7 inch rubber backer pad on a Black & Decker 9" Wildcat grinder to remove scale on hot rolled steel, and the trick to keep from gouging is to keep it moving fairly rapidly in large sweeps so that it averages the cutting better. This is also how I clean weld splatter off the welding table. The weight of the larger grinder makes a difference in how it cuts.

RJ

 

[grego]

Would the scale cause issues with grounding much like having rust scale on a frame or similar situation. If it is on there as good as you say, I say leave it. Worst case is you try it and it doesn't work then you have to grind/polish it all off. A flat smooth surface would be the best for welding if you are going to permantly ground it to your welder. Just my .02

 

[StumpXJ]

Nah, it works just fine. I was just thinking it should come off until I started actually trying to get it off easily.... now I am thinking it will stay on there. I have an extra ground wire from the welder bolted to the table, but I also still have the long lead with the clamp. It works just fine at this point, so I am not going to waste the effort to get it looking a little prettier.

~ James

 

[ZRX61]

Doesn't muracic acid remove it?

My welding table is also covered in scale.. except one small 1.5in square area where I put the ground clamp