How do I clean cement residue from a cement mixer in order to repaint the machine.?
Answers:
Muriatic acid. It's the same thing used by most concrete companies to clean their drums. Most drivers carry a diluted mixture to use on the jobs, and a stronger strength is used to clean concrete buildup along the top of the drums.
When using a stronger solution, wear rubber gloves, apply the acid, and let it do it's thing. You'll see a chemical reaction almost immediately after the application. Googles are also a precaution that needs to be taken. It may take repeated applications to get a large buildup off. Wire brushes are good, as long as you're not worried about abrasing the surrounding surfaces.
Other answers:
pressure washer
pressure washer
try 1 to 1 mix
I use muratic acid mixed with water to a 50-50 solution and then I spray it through a hand held pump up sprayer. You can pick up a pump sprayer at any wal-mart. Good Luck.