Good tool for removing mill scale?

Date 07-22-2002 22:15

Dave,

Mill scale can be pretty tenacious sometimes. If it takes too long with a grinding wheel, a wire wheel will only take longer, if it gets it off at all. I think your best bet will be to get a stone to fit your grinder (make sure it can handle your grinders rpms) to get mill scale off. If you can't find a stone, get the coarsest grinding wheel you can.

By Dave

Date 07-23-2002 13:23

A needle scaler works well too. But to get it ALL off, short of shot or sandblasting, nothing works as well as a grinder.

By G.S.Crisi (****)

Date 07-23-2002 15:39

Depends, Dave. If you apply "Sandblasting to white metal", you'll remove ALL of the millscale. Now the question is: do you really need to sandblast to white metal? This is a very stringent condition which applies very seldom.
Check out which is your real need.
Giovanni S. Crisi
Sao Paulo - Brazil

By DaveSisk (**)

Date 07-23-2002 16:30

Good question. If you paint it with primer and paint without removing the mill scale, isn't there a good chance that the mill scale (which to my understanding is the metal flakes that adhere to the metal) will come off and take the paint with it? (This is in reference to some steel framed end-tables...)

Dave

By stich585 (*)

Date 07-24-2002 03:54

Sometimes if the mill scale is lose you can blow the mill scale off with a oxy/acetelyne torch. Use a big tip (#8) and turn the oxygen up higher than you normally almost blowing out the cones. Also, in regards to sand paper, Tiger makes a sanding disk composed of strips of sand paper stacked on top of each other in a circle. These ROCK on all light finishing applications.

By billvanderhoof (****)

Date 07-24-2002 04:53

Mill scale is mostly black iron oxide (Fe2O3) it forms on hot steel when it is exposed to the atmosphere as in a rolling mill.

You have allready demonstrated to yourself how well it is attached. Fabricators that I know of brush off the loose stuff and paint it. Good primer should stay on fine.

If you want the most agressive wire brush get the one with the bristles twisted together into bunches. It will be called knotted.

Another approach to removal is to convert the scale to rust (Fe3O4) then brush that off. Dampen and leave in a warm humid environment. Overnight on a dewey summer night should do it.

If you can find a source for the small quantities you use buy cold finished, it has no scale.

Bill