first time tiler here. did some mosaic backsplash in the kitchen. a mix of glass and marble tile pieces. 1/16 grout gaps. used Mapei Keracolor (unsanded) in color called biscuit.

so I saw in the Mapei bulletin the following, "To prevent efflorescence, discoloration and soft/powdery joints, avoid cleaning with excessive water." so I was very, very careful to wring the sponges almost bone dry and used light pressure. sopped up any excess water. still got a lot of areas where there is whitish haze on the grout lines, especially along the edges. but I have some grout lines that have basically turned white!

so short of scraping the bum areas out and doing it again, am I just out of luck here? or is there another solution? like can I let it dry overnight an rough it up a bit with a scrub pad or toothbrush or anything? ie, is this type of discoloration mainly superficial and I can kind of scrape it off? or maybe they (Mapei) sell like a touch up pen; guess I can look.

any advice is appreciated. cheers,

THB

 

What you have is most likely latex leaching.

Try wiping with hot water. Allow to dry a few hours. If the results are not good enough, try a 10-20% white vinegar/water mix. That should make it better. Otherwise allow to cure about 10 days and wash with Sulfamic Acids crystals de solved in water per directions.

Note: acids & cleaners can dull natural stone & etch metallic tiles. Always test all cleaning products before using.

Jaz

 

thanks, Jaz (x2; I see you on another forum too). will try the hot water. then tomorrow night maybe the vinegar

take care