Very informative and enjoyable site.
I have a problem and am hoping that you could help me. I procured a number of products for purposes of cleaning and sealing a new PA non-variegated Bluestone installation. The tiles are square cut ~ 1" thick with a thermal finish laid on a 5 year old concrete porch using 1/2" mortar bed all according to your instructions on your website. The job was finished last fall and the multi-step process was started ( i.e. cleaning, grout residue removal etc...), but cold weather came early and the procedure was not finished. No sealer was applied. No salt was applied during the winter by the way. At the time the stones look nice and uniform with a light blue cast.
Now, the problem. When I went to apply re-apply the multi-step process ( i.e. Cleaner ( TileLab stone cleaner/stripper, Grout residue remover and Efflorescence treatment). I never made it to the sealer step because I was unhappy with the results thus far.
Here is a link to the TileLab product if you wish to view it---http://www.custombuildingproducts.com/ProductCatalog/newcare/newcleaners/HeavyDutyCleanerStripper.aspx?user=diy&lang=en
The area does not look good contrary to what I saw last fall. There are areas that are streaked looking with what appears to be patches of a white deposit in the stone, with very light brown streaks in other tiles. Some areas actually look dirty even after cleaning them. I have included pictures for you to see.
I tested the white powder areas with drops of concentrated grout remover and they did not seem to fiz, nor did the brownish areas. I tried spot testing the efflorescence compound and while it was wet it looked better, once it dried it returned to its original state.
I thought possibly that these stains could be non-mineral and thus tried a solvent Toluene, but it did not seem to do anything.
Any ideas of what this is of what I can do? Someone recommneded soda blasting or a stronger acidic cleaner.
If you require more photos I have them or additional questions, please feel free to email me. I also have larger file sizes that I can send which are more detailed. spkl350 at hotmail dot com
Thank-you for your assistance