Rubber coated RS valence

[hogdaddy]

Originally Posted by Too Many Projects

Muriatic WILL etch the metal. It needs to be diluted a lot to be safe for the metal and then it works much slower than his results.
If you are going to use it, have a large enough tub to submerge the entire piece to avoid etch lines like I got soaking my fenders one side at a time. The etch will be uniform and if rough enough, supply the "tooth" primers want to grab the metal (substrate) That would eliminate needing to hand sand with 80 grit.

He mentions a stronger muriatic acid and Lowe's sells it I believe but he uses it full strength in video.