Jennie57 asks: "... now the glass looks really dull. Is there a better to solve this problem?"

We approached the same problem when we chose Senio Il Vettri glass tile for our backsplash. Our tile is not colorless clear, but translucent and amber; our solution was, instead of affixing the tile to the wall with thinset, to use Dow 999-A as a mastic. We are happy with the result.

Our installer made sure to back butter all of our glass tile with white thinset. It looks great and the glass is brilliant and super shiny.

Tyically white thinset will be notch-troweled on to the wall, that puts a measured amount of thinset on the wall. Then the notches will be knocked flat with the flat edge of the trowel.

The transparent glass tiles can then be rolled on to the thinset, rolling prevents entrapping any air bubbles between the tile and the thinset.

If the tile has texture, or if it makes things easier on the installer, the backs of the tiles can be buttered with a bit of thinset as wisco-sailer wrote.

Were told to paint the back of the tiles by the manufacturer? By a friend? The salesperson at the tile store?

I wouldn't advise mastic as mastic can yellow over time. But with amber glass like the previous poster had installed, yellow discoloration may not skew the installation unless it was uneven and blotchy.

I can see the thinset notches through my glass tile in a shower - the installer did not knock the notches down well enough, and about 20% of the tiles look like they have "worms" behind them (squiggles of thinset).

Should I "pitch a fit"? You have to be rather close to the glass tile to see it, and the shower probably won't get used a lot. Tiling in the showers is holding up the finishing of our house, and we are tight on time (mortgage rate lock period getting close to the end).

How hard is it to take them down and replace them?

Jennie57, sorry to somewhat highjack your thread, but the title for my thread would be exactly the same as yours!

mongoct writes: "I wouldn't advise mastic as mastic can yellow over time."

What I wrote was that we had used Dow Corning 999-A *AS* a mastic. Dow 999-A is not your garden variety mastic; it is a silicone glazing sealant. In its primary application, color stability over an extended period is an important criterion. It is no more likely to yellow than the silicone spatula in your kitchen drawer will yellow -- probably less likely, in fact, because behind the tiles it is not exposed to the ambient air.

That 999-A also has exceptionally strong adhesive properties is what allows it to be used as a mastic in an "off label" kind of function. Of course, we applied the 999-A as dabs on the backs of the individual tiles rather than troweling it onto the wall as we did with thinset in other tiling jobs.

Here is a link that might be useful: Dow's datasheet on 999-A

herring,

When I wrote to not use "mastic" I'm referring specifically to mastic adhesive. They can yellow over time.

I'm sure I confused the issue by including the reference to yellowing versus your amber tiles in the next sentence. My apologies.

I didn't mean to infer that your 999-A silicon was mastic. It's not, as you know they are two different animals.