Been making a boat load of brackets out of 1/4 x 2 flat bar at work this week. The bar has a ton of mill scale. The kind that's a nightmare to try and grind off.
A 30 minute soak in muriatic acid is dissolving it right down to fresh steel.
The acid I'm using is thicker than others I've seen. I got five one gallon jugs at my local Ace Hardware. It has a consistency of thin syrup.
I give them a good rinse and later, before paint, a wipe down with MEK.
if you'll cut it to a 50/50 mixture with water the fumes aren't as harsh.
I use it all the time for may plasma cut stuff in a 4ft tank.
Don't use it inside or the fumes will rust everything in the
shop that is bare metal.
I made that mistake once. I had a closed jug in a closed cabinet and it still managed to rust the tops of my table saw, band saw, jointer, etc. Everything that had nice shiny machined surface had to be reworked.
I've got some mandrel bent tubing from speedway that is bluish black in color. Is that what mill scale looks like? Sorry for my ignorance I don't know squat about metal.
I've got some mandrel bent tubing from speedway that is bluish black in color. Is that what mill scale looks like? Sorry for my ignorance I don't know squat about metal.