bluestone cleaning and sealing

[chesterflick]

The blue stone was grouted with type s masonry and never cleaned well. Now the contractor wants it cleaned and sealed. I can't seem to get it 100% cleaned using sulfamic (light) or some acidic cleaner from dupont. I am only doing sample areas. Will use a wet vac next to make sure the water does not soak back in. Any suggestions ?

[Davy]

Tom, I assume you are also scrubbing as you are washing.

[chesterflick]

Thank goodness it has been cleaned and sealed and looks great . This is the mud job I talked about a few months back where the installer did not bond the mud to the slab and just rolled on some water and Portland as the bond coat to the stone.
it was ongrade and no one installed any expansion joints because the contractor said he does not like the looks of them even though in section 9300 there is a specific related section to division 6. I wrote my letters,told the boss, jumped up and down and told the project manager for our company that when it fails,and it will within a few years that if he tries to make it my issue I was going to do every thing in my power to make sure he is banished to carpet land for the rest of his life because he has no business doing tile.

[chesterflick]

My favorite bluestone job has issues. Much of the stone will not come clean.
History: most of job on depressed slab. Stone installed with type S masonry and grouted the same. Stone has been was with concrete cleaners and I have even been told muratic ( if you can believe it ) stairs,stairs were installed and grouted same way I think some of the uncleared stars were sealed with a penetrating sealer. My biggest issue is that I threw up all the warning flags on this job from the beginning and was ignored. I am the one they look to now for a solution. Any help would be appreciated. Let me take some photos and send along if I figure it out