Websep 14, 2009 · 4 days ago we grouted our new 1 hex bathroom floor with oyster gray prism grout. It looked beautiful and seemed to dry nicely. Today during some cleanup i noticed. Webandriy (aluchkovsky) sent me 3 lbs of the prism grout he’s been having problems with. I in turn created a test board and then grouted it as you will see below. For the test board i. Webwe've never run into this issue before, the grout had 24+ hours to dry and the shower has only been…