Removing mill scale

[drivermark]

When we have to resort to using hot rolled material the mill scale can be a real bitch to deal with. In a HOMEMADETOOLS.com blog dump a while ago a guy had a really easy way of removing mill scale with of all things vinegar.
Here is a link to the vid.
https://www.homemadetools.net/forum/sim ... post183664

Now it's not a quick method but it is easy, it just takes a little planning so you don't end up with a bunch of down time (if that's an issue).
I tried it out in my shop and I can say, it does work and it works well, you just have to soak your material for about 4-5 days for it to disolve all the scale.
Thought this was interesting and just wanted to share.

[budoka]

hmmm, nice tip. i sure do hate mill scale.

-dan

[railroad bob]

I watched the video, interesting method, useful for projects with small pieces and pre-planning.

Being a welding inspector, I've seen considerable mill scale, and always considered it to be flaking on the surface.
I had to look a little farther, did a search on mill scale. Was surprised to see the blueish color is also scale.
And I found a site about it's impact on welding.

In short, the condition shown in the video is not much of a concern for welding except for TIG.
The gentleman who posted the video shows a grinding disc he uses to remove the scale, but others have more success with sanding discs. They come in various grits depending on how aggressive you need to be.

https://weldersmanual.com/mill-scale-sh ... remove-it/

[drivermark]

I was thinking more along the lines of removing the scale for making parts for forks and such. Soaking in vinegar for a few days is much easier than trying to sand/grind thru all that shit to get to actual steel. It also saves on sanding belts, grinding wheels, and elbow grease.
Also I figured out the hard way that if you soak your parts to be in some lacquer thinner or acetone to remove the oil and grease, the vinegar works better and lasts longer.

[railroad bob]

Ah, more good ideas. Makes sense the vinegar wont cut the oil very well.Might not have to soak the parts, just a wipe down might do the trick. Maybe not have to use so much acetone/thinner.
But I can see having a dedicated container of thinner to put small stuff in, reuse it as needed.