Home » Categories » Natural Stone Q & A’s

Bluestone grout stains

My mason laid a bluestone porch and when he grouted with portland the grout left stains around the perimeter. I dont want him to clean it with muriatic acid as he suggested. Another mason said to use a floor polisher with a nylon abrasive pad and a solution of water and ammonia 16:1, and then a color impregnator #511(?). What is the best solution?
 

Dear Rob:

Without actually seeing your installation I can't tell for sure. You're making reference to staining, but are we actually looking at a discoloration, or only a residue of grout film sitting on top of the stone?

It is quite possible that it is a film residue and, if we have to go by that assumption, the words natural stone and acid (especially Muriatic!) should never appear in the same sentence. Water and ammonia? I never ever heard that ammonia could remove grout film and I actually highly doubt that it would. I'd rather consider using a specialized heavy-duty alkaline cleaning agent with chelates in its formula like MB-3 with a floor machine and a scrubbing brush instead of a nylon pad; the nylon pads would get shredded pretty quickly – not to mention that is not as effective as a scrubbing brush. MB-3 is indeed very effective and is rated “for natural stone”.

Finally as for the sealer, it is never a good idea to apply an impregnating sealer to stone installed outdoors.

May I ask you now to please read and e-sign our Statement of Purpose at: http://www.marblecleaning.org/purpose.htm?

Ciao and good luck,

Mauri z io Bertoli

 

www.marblecleaning.org – The Only Consumers' Portal to the Stone Industry Establishment!
Attachments Attachments
There are no attachments for this article.
Comments Comments
There are no comments for this article. Be the first to post a comment.
Related Articles RSS Feed
swirl marks
Viewed 0 times since Thu, Nov 1, 2007
Choosing a floor that will withstand 4 dogs.
Viewed 0 times since Thu, Dec 6, 2007
grave marker cleaner
Viewed 0 times since Thu, Jul 12, 2007
cracks in the granite floor
Viewed 0 times since Thu, Sep 20, 2007
travertine tile backsplash mural
Viewed 0 times since Sun, May 6, 2007
Granite quality
Viewed 0 times since Wed, Oct 24, 2007
absolute black granite - honed
Viewed 0 times since Sat, Dec 29, 2007
enhancing tumbled marble backsplash tiles
Viewed 0 times since Mon, Jun 22, 2009
dull marks on black galaxy
Viewed 0 times since Wed, Aug 22, 2007
Green Peace Granite - suitability
Viewed 0 times since Mon, Mar 3, 2008