Acid and Slate

[Goomer]

These pics were sent to me from a customer and restaurant manager who recently transitioned to a new restaurant.

The condition of the grout makes me think it may benefit from some acid after cleaning, but the fact that it may be slate has me concerned.

The manager is trying to inquire for me if it is in fact natural slate, as I have not seen it first hand yet.

I am reading differing opinions on whether acids can be used on grout when natural slate is involved.

Some say yes......some say no.......what say you??

 

[Mark Saiger]

Don't know the answer to the acid and slate question but it almost looks like a mop with wax residue is being used as it is slopping up the b0ttom tile....

Just a thought as I have had a few occur with this....

If so, Wax remover has been a great friend....

Have a feeling the acid could be bad for the stone, but will wait for the real experts who deal with that....

 

[Mikey P]

No calcium in slate..

Use all the acid you want.



But test 1st cause the bottle says so.

 

[Cameron DeMille]

Some slate is acid sensitive, some is not. Always test

 

[Mikey P]

Never seen a polished slate....

 

[Cameron DeMille]

Doesnt have to be polished. It can turn white more are not acid sensitive than are but I would test just in case.

 

[clean image]

I have seen it turn white, also have seen the darker colors bleed.
that slate "looks" common, should be fine.
You will def need acid in that bathroom environment

 

[Goomer]

Whats your standard acid test procedure?

 

[Cameron DeMille]

Whats your standard acid test procedure?

Put acid on the slate in an inconspicuous area and see if it reacts. Or on a spare piece

 

[Goomer]

Put acid on the slate in an inconspicuous area and see if it reacts. Or on a spare piece

I am assuming it should be tested before cleaning and when completely dry.

"Reacts" as in bubbling?

How long should one wait without a visible reaction to deem it safe?

After the test and the acid is blotted up, and the test area is dry, any damage will likely make the test area appear lighter?.....Darker??....Depends on the stone??

 

[Cameron DeMille]

I am assuming it should be tested before cleaning and when completely dry.

"Reacts" as in bubbling?

How long should one wait without a visible reaction to deem it safe?

After the test and the acid is blotted up, and the test area is dry, any damage will likely make the test area appear lighter?.....Darker??....Depends on the stone??

I just do a few drops in a corner of the room or something, not a whole tile or area. It should fizz within a few seconds, but I'll leave it on 10 seconds or more. I like to try a couple different spots. If there is no affect, then I will go ahead with the job.

If there aren't any good test spots, try behind a door or really close to the baseboard in a corner, or under an area where something will be, like a pot or entertainment center.

 

[clean image]

In that bathroom, your gonna need an acidic cleaning solution to get those grout lines clean..

Don't be alarmed if is duller where you do test, as I guarantee there is a false shine on the floor.

 

[Cameron DeMille]

I wasn't even thinking about the bathroom floor, but yeah just dump whatever you want on that one.

 

[Goomer]

Update...............I tested the slate and no reaction was observed.

In the end, I did not even wind up acid treating the grout, because what I originally believed, which was based only on the pictures, was that the grout was light colored, and just really dirty, but the grout was actually dark, and the lighter stuff was just crud.

Nuked it, scrubbed it good with my trusty lil' Orbiter, and sucked it with my super Porty........

 

[Mikey P]

Beautiful!

 

[Cameron DeMille]

looks great

 

[mirf]

Nice job! Did you get more work?