I’m in an underground garage that has thick calcium Deposit coming down the wall (painted concrete). I’ve given it about 15-20 coats of pure EchoChem One Restore (I was told it was the best option for this) - sometimes giving 20 minutes of dwell time / reapplication. Then hitting it with a power washer rated at 6gpm and 3500psi.
I’d this stuff just too thick for pressure washing to be the right method to deal with it? Am I doing something wrong?
Photos attached.
That looks more like rust/iron staining then calcium.
You probably have a combo of rust from rebar reinforcement and efflorescence from the water as well.
Calcium stains are usually white but can be tinted mixed with dirt and other minerals.
Eachochem also has a writeup on various white stains and associated treatments: White Deposit Issues - EaCo Chem
They do also have a service you can look up named “call from the wall”. Give them a call or email while on a job and they’ll give you some quick assistance to identify your issue and remediation. Great guys.
Oxalic acid on it that should get the mineral rust off. That is what I see in that picture. Just be careful with it wear a mask for acid since your are in enclosed space. be safe out there.
@MrShineProWash and @dodger8899 Thanks for the responses guys. Yeah, I previously hit it with Rust Remedy from SESW. Both chemicals show a visible reaction on contact, so it’s definitely a mix of iron from the sprinkler system above the garage and mineral deposit. I guess to clarify my question - these aren’t just stains on the wall, it is a physical layer of deposited material (like a cave formation) built up on the wall. Is it at all reasonable to think chems and pressure can “melt” this away and remove it, or should I refer the client to someone who will grind or sand blast this stuff? I was hoping for a could applications of chemical that would soften the mineral and cause it rinse off, but that’s not at all what I’m seeing. If there is a chemical that can do this, what is it?
Muratic acid will get minerals off but it etches concrete. And is very hard on the lungs because it off gassing .
Here is what I would do back away form this. Have them to find their own source to get it cleaned. It would save you headaches and trouble.
Much appreciated. My desire to be helpful has gotten me into hot water more than once 
