View Full Version : Mill Scale on Hot Rolled Steel is Tougher than a Pigs Nose!

07-11-2009, 01:10 PM
What's this stuff made of, all the carbon floats to the surface and you end up with a layer of high carbon content bullet film that eats tooling, next to impossible to sand, and is a general pain until you get through it?

Seems the trick is to take a deep enough cut to get beneath it, then you home free, other wise it's next to impossible.

I thought the brain trust here might have few other suggestions?

07-11-2009, 01:16 PM
Here is a post by Forrest it will help you out.


07-11-2009, 01:51 PM
Soak it in the cheapest white vinegar you can find for 8 to 12 hours & wash it off with a water hose.
Yea...it sounds like a joke, but it works.
When you're done, throw the leftovers on any weeds you want to get rid of. It's a great weed killer.

"Make Swarf & Prosper"....John

07-11-2009, 02:18 PM
Outstanding Gentlemen! I would have never thought it would be so easy, thanks for the reference and advice. I am off to the store now....good bye mill scale!!!!!

07-11-2009, 05:41 PM
Never tried vinegar but I will attest to the muriatic acid soak.. works great.

Liger Zero
07-11-2009, 05:44 PM
Boss showed me a trick at the last fab shop I worked at: Bend it. The distortion of the skin fractures the stuff and it falls right off.

Of course this is not practical in all situations. ;)

07-11-2009, 07:58 PM
I know about pickling it, but how about a grit blast? never tried as my compresor is a bit weedy, just a random thought [mostly i use bright drawn for machining and the black stuff for fab]

07-11-2009, 08:01 PM
When I used to build rotary tables for Armco Steel we used large acetylene torches with rosebud tips. The quick intense heat causes it to expand so fast that it comes right off.