The Brew Cabin

Posted: **Thu Jan 31, 2013 3:00 pm**

Hi, great site and forum guys!

I've read various advice on this, so now I'm looking for the "definitive" answer!

Our black limestone has been laid indoors for the kitchen.
There's no grout yet but after a few passes with clean water, a scrubbing brush and lots of towels, there's still a variable amount of cement haze left from the bedding mortar.
I understand that acid is definitely not the answer, so wonder whether this product:
"Aqua Mix Grout Haze Clean Up"
(suggested on Tilersforum)
which is advertised as being acid free,
would do the job prior to using:
"Romex colour seal"
as "recommended" in the black limestone treatment tests to be found elsewhere on Pavingexpert ...
It may be that the Romex (or LTP mattstone?) will block out the haze initially but I'm guessing it's worth getting rid of as much as possible first.
All advice based on experience very much appreciated!
Many thanks

Posted: **Fri Feb 01, 2013 9:36 am**

I'm not sure that jollop really is 'acid-free'. The list of ingredients includes a lot of summat by the name of EDTA, which is a big name, but the important thing is the A stands for Acid.

EDTA is commonly used to dissolve limescale, so I'm assuming it's not as strong as, say, Hydrochloric, but it's still an acid so there's a risk of bleaching the black limestone.

You could try it on a discreet corner, I suppose, but I have no experience of using it, and it's not a product that has been mentioned previously in the many discussion I've had regarding black limestone.

And those discussions have still not identified a suitable cleaner of cement, mortar or cement-haze from acid-sensitive stone. The big problem is that the chemistry of cement and that of limestone is pretty much identical, so if a product dissolves one, it dissolves the other.

At the moment, I'm still recommending elbow grease and a simple cleaning agent such as Grundreiniger to remove hazing. No-one would be more delighted than me if we were to find something that could achieve acceptable results with less elbow grease and in less time.

Posted: **Sat Feb 02, 2013 10:57 am**

Thanks for that ... I guess I'm resisting the "elbow grease" cos I've just broken my main wrist!
The other product that has come up is LTP's "Grimex" so will contact them direct and check for ingredients with "A" on the end

Posted: **Tue Feb 05, 2013 2:32 pm**

Grimex is slightly alkaline, so while it should be safe on limestone, it's debatable how effective it would be on cement staining.

The Brew Cabin

Cement haze on black limestone laid indoors - Stain removal