slate mosaic - grout going brown

[grovetile]

Hi
Has anyone come across this?
I cleaned and sealed the mosaic first with Lithofin. Then stuck them up with BAL single part flex.

But now the white grout (BAL) seems to be going brown around the mosaic.

Disaster...

can anyone help?

thanks

[Dave]

Could be contamination from the tile edges..( dirt)...have you any pics..?

[grovetile]

[IMG]file:///Users/shona_hill/Library/Caches/TemporaryItems/moz-screenshot.jpg[/IMG]
There's photo of them

[timeless john]

In which location has the Slate Mosaic been used - Shower/kitchen splashback/patio/plant pot....

Timeless John.

[grovetile]

for a couple of borders in a bathroom. It's going brown while it's being put on...

[Rob Z]

Grovetile,

This happened to us about 6 years ago with some slate that seemed to be of good quality. We sealed it 3X before grouting with epoxy...everything seemed OK until we started striking the grout with the float, and then the damn stuff was coming off the surface and edges of the tiles. We lost a lot of time on that one...spent hours trying to make it right. The customer was happy with the finished product but I swore I would be much more cautious about slate after that. A buddy of mine has been having the same problems lately and it seems this stuff is coming from India and China. When I first started in the trade I don't recallany problems with slate, but now-a-days I think there is a lot of junk on the market.

[grovetile]

So what's the answer... scrape it all out and start again?

[Rob Z]

Grove, we just kept cleaning until it was acceptable to the customer. I never was happy, but she had supplied the slate so I couldn't demand to tear it out and start over. I think with all our cleaning we eventaully drug out all the crud and got down to solid stone.