Mapei Unsanded Grout and Mapei Maximzer Turned Yellow

[SeattleIS300]

Anyone have any experience with Mapei Unsanded White Grout and their Maximzer turning yellow?

I installed around 60 feet of Glass Tile and the Grout joints are turning yellow. It started faintly at first but it's becoming very dark.

https://www.lowes.com/pd/MAPEI-Grout...ive/1000057499

https://www.lowes.com/pd/MAPEI-10-lb...-Grout/1119247

I used Custom's Glass Setting Mortar to set the tile.

https://www.custombuildingproducts.c...et-mortar.aspx


From what I've read it's usually Yellows from using the wrong water type but in my scenario I used the grout maximizer in lieu of water.


Any idea if grout paints or dyes might work to dye it back? It's on accent wall in a bathroom with zero water exposure.

Any insight is appreciated.

Joe

[Karls tile Inc]

Do a sample board with no maximizer and then see what happens.

[MAPEI - Technical Service]

Joe, I have to say that we don't have a lot of 'yellowing' complaints with Grout Maximizer. As you state, it's supposed to minimize issues, not cause them. We do have a product called Grout Refresh that will restore the color. Sorry for your issue.