Looking for steel...

[JAZZCNC]

That's just weak Hydrochloric acid (5-10%) you'll be able to find 28% hydro acid for similair or less money (I sell 25Ltr for £13.50). Often it's used has brick acid or toilet/drain cleaner so try builders merchant or if got local chemical supplier pay them visit has it's common and cheap.

[thinfourth]

I find running steel strip through a ring roller takes most of the scale off

So make/build a ring roller

Run steel through to make a curve

Turn steel upside down and run through again at a different setting to make it flatish