Removing Mill Scale from Plate

[downsizingnow48]

Maybe I am the last person in the world to figure this out. The problem was, how to remove mill scale from an 18x48 piece of 3/16 plate. Yesterday I did an experiment. I laid out paper towels on a piece of plywood, then soaked them in vinegar. Put the plate on top. Laid more paper towels on the plate and soaked them. I started about noon yesterday, resoaked with more vinegar about 8pm, then started cleaning up at 6am this morning. First I used more vinegar with a scotch pad to loosen the crud, then Simple Green with paper towels to get most of it off, then spray glass cleaner and more paper towels to remove the last of the residue. This is much easier and cleaner than a stripping disc. Black glop on the paper towels vs fine black powder all over everything. Maybe there is an easier method, let me know, I have more plate to clean.

 

[GPintheMitten]

Nice job. I learned something from you. I don't know of anything better or easier.

 

[CNC Dan]

You might try a stronger acid. You can get hydrochloric acid used for cleaning concrete.

 

[rsallen]

The nice thing about vinegar is no hazardous waste cnc.
In fact none of the associated garbage that goes along with any of the stronger acids.

Thanks downsizing, I've got a half a dozen or so large pieces of plate out back I'll want to cleaned up before doing something with them. If I out figure out any modifications on your method that's any better I'll let you know.

 

[kennyd]

The secret is buying HRPO plate, only a little more $$ but well worth it.

 

[downsizingnow48]

KennyD is right on the HRPO, local supplier can get it special order with 2 day lead, costs close to 2x plain hot rolled. Of course by the time I do my own pickling (last night), and wipe it down with oil to prevent rust (this morning), that cost differential starts to look not too bad!

 

[roadhunter]

Interesting method that sure looks like it works.

 

[rsallen]

The secret is buying HRPO plate, only a little more $$ but well worth it.

The thing is ken, I got my plate for nothing but my time for loading and then unloading here.

 

[charlz]

Vinegar works good for rusty pieces as well, takes longer though, sometimes a couple of days. We have very base soil here that locks up the iron in the soil. When I dump out the used vinegar and rust it greens up that spot on the lawn

 

[Egon]

For real clean ?

Needle scaler, posphoric acid, sander, paint.