Kelly is a professional tile installer. She has given us her pro method for grouting. It’s valid for large or small projects.
If you use dry grout, mix it up with the acrylic admix. Smush the grout in with a grout float. For the final pass run your float at a perpendicular angle to your piece to get most of the residue off. Do not press down too hard, or you will pull grout out of the gaps between the glass. Let this sit a few minutes until you get a bit of a haze. Then lightly sprinkle some dry grout over the piece. Take an 8×8 inch piece of old towel or carpet remnant, and buff the piece with the dry grout on it. Work the dry grout over the joints using a circular rubbing motion. Again do not press too hard. You will end up with very smooth grout joints right up at the top of the glass.
Since a few of you have told me you have saved this idea already… make sure you do not let your piece sit for too long after you have grouted. 10 minutes or so is probably good. You will end up with grout residue to deal with if you wait too long, and it may dry out too much to be able to buff the dry powder into it. Remember to use a light hand when swirling so the glass does not scratch. You may want to test the glass first. You should not have to use a wet sponge to clean at all, because swirling the dry grout around takes all the excess away and just leaves it where you want – in the joint. If you do have a powdery haze after the piece is completely dry, just use a clean rag to buff it off. If you ever get any grout residue that has dried too long on your glass (like overnight) try taking it off with plain white vinegar before you resort to muriatic acid. Rinse really well afterwards.
With grouting, I would stress a light handed approach. I know some glass is more scratch resistant than others. Of course, with a mosaic you would not be as likely to see scratches since the light does not shine through. This technique works well for any type of mosaic work, glass to glass or stone (e.g. marble or granite).
It may work for 3-D mosaics if the dry grout is scrunched up on a rag and swirled around. I have not tried that yet though. I really like to maximize the reflective qualities of glass, so I have had thoughts about making some glass to glass mosaics. I think a glass to glass coffee table, or end table would be very cool. Now I do make stone mosaics out of granite, marble, travertine, etc. That is a lot of fun! I incorporate both broken and cut pieces in my designs. Actually, I am going to mix some glass with natural stone for a mosaic to put on the backsplash of my husband’s next spec house.
You really should not use glass on a floor since it will scratch after a while. When I first learned how to make stepping stones I thought that a natural stone (marble and granite) and glass stepping stone would be really cool. The indirect technique would be ideal since the granite is much thicker than the glass, and natural stone and glass are a beautiful combination. Give it a try sometime. You can get a $100 wet saw at Home Depot to cut your stone (this girl uses any excuse to buy a new tool ), or you can break the stone with a hammer. Let me know if you want to know more about this. There are so many people out there selling stepping stones. This is a wonderful way to make them a little different from the rest.
Silicon Folly Note: If there are questions about this method or additional info is required you can e-mail Kelly, the author, at JKeells@aol.com.