I realize there’s a megathread about discs, but my question is specific to mill scale removal, preferably with NO metal removal, or, minimal, at best. Not talking about blasting, chemicals, strictly grinding discs, wheels, or anything else that can be used on a right angle grinder. Quite a few people on this forum, and many are subject matter experts, within their specific field, so what says the hive?
And please don’t say “use vinegar”…
While I haven’t the wild amount of testing that’s been done here, I can say these work, don’t last super long, but they do work.
Without knowing your exact requirements here’s some suggestions. Sometimes just heating the area with a cutting torch or rosebud will pop or loosen the scale off without corse abrasives. Then a wire wheel will remove the rest.
Here some abrasives if I’ve used depending on my application.
You can get these in 4.5 diameter
https://www.3m.com/3M/en_US/p/d/b40064927/
https://www.3m.com/3M/en_US/p/d/b40064937/
Diamond wire wheel
Walter mill scale disc for aggressive thick scale removal fast.
3m clan and strip
Have you actually tried the Walter flex cut discs? I have tried many different 3M clean and strip style products, various brands including 3M, but not the Extra coarse version. They all seem to either wear rapidly or clog up. I did watch a few videos about the diamond coated wire wheels, and while they seem like exactly what I want, they are PRICEY.
This might sound crazy, but after trying a dozen or so different discs, and then watching videos about the diamond coated wire style, I tried a segmented diamond wheel, made for fine surfacing concrete, and it actually worked really good. The downside is that you have GOT to keep the wheel perfectly flat on the steel; otherwise, you will nick the hell out of the steel. You also have to have a good grip on the grinder but still be able to “feel” that it’s flat against the steel, all the while keeping it moving and use firm, but minimal pressure, otherwise the wheel will dig in and the grinder WILL take a walk by itself, as well as trashing your surface.
I wish I had a perfectly flat plate and a nice big straight edge like you have; then I could have checked with a feeler gauge to see how well it actually worked, but it just isn’t possible. It did seem to work well, without leaving any gouges or divots, and I followed up with a 3M clean and strip disc to blend in some of the scratches left by the diamond wheel, and it worked pretty good. Not a mirror finish, but smooth enough that you can’t get a razor blade corner or a dental pick to grab at all.
Anyway, thanks for the replies guys!
Yes we use it in the shop. I even made a video on it. It’s aggressive so you have to be careful.
KONIGEEHRE 12 Pack 4-1/2" x 7/8"… 12 Pack 4" x 5/8" Strip Discs Stripping Wheel Fit Angle Grinder Clean and Remove Paint Coating Rust Welds Oxidation - Amazon.com
