On Sun, 27 Feb 2005 10:49:08 -0700, "TT" wrote:

Is there a chemical method to removing mill scale? I'm working with 14ga and
removing mill scale is just time consuming and generally not a fun job. I
hit it with a stone disc to get the majority of it off & then flapdisc to
desired finish. Among other problems is that heat generated from the stone &
flapdiscing will sometimes warp the piece.

Anyone know of a chemical method? How about muriatic acid? Do they make a
"stripper" chemical for steel?

Alternatively, I hope to buy a blasting gun & cabinet soon, what kind of
media should I use to remove mill scale? Would walnut shells do the trick or
will I need something harsher?

Blasting with glass beads removes mill scale very nicely. However,
you may get a bit of distortion on steel as thin as 14 gage. Walnut
shells are less likely to cause distortion, but I don't know if
they're aggressive enough to remove mill scale.

Muriatic acid will do the job.

The metal must be protected (painted or clearcoated) very soon after
blasting or acid stripping, or it will rust.