I stuck my luna moth on with thinset. Maybe you should try this with thinset rather than grout. It didn't discolor or stick to the glass either. I know that sometimes a thick layer is used instead of grouting. I think the key thing is that the glass is not oily or greasy (even from your hands). You know that makes me think - maybe rub your fingers over the top of the glass before grouting. maybe the tiniest bit of oil, you wouldn't want it to run down the sides. I could run my fingers through my hair and the grout wouldn't stick, in fact I think I've gotten things greasy by handling and that's why they have fallen off.
Good luck. You are going to have the sea glass figured out and we will all benefit!
Dh and I are going up to Blue Hill Maine for a couple days after we spend a couple days in Harpswell where he spent many years of growing up. I know you are quite a bit further up, but do you have any recommendations for a mosaicker junker gardener hiker (with our little doggie) that we might want to see or do?
Kathy

I saw the thinset when we were at Home Depot in Ellsworth a couple of weeks ago. Wish I grabbed a bag, I had no idea what I would need.

The glass looks great on the pressed in version, it is drying will see if the glass just picks right out or not.

I wish I new the Blue Hill area better, I know there are lots of pretty farms out that way. Did you check out the Moose Point State Park? Maybe there? Have FUN! and Enjoy Harpswell!!

Here is a link that might be useful: Moose Point

I am thinking that grout is not a substitute for glue. I would recommend using thinnest (mortar) instead. I know that you can use thinnest for both adhesive and grout so it would work.

Thinset is inexpensive, it goes a long way, you can get it in white or gray and color it. Slow uses it as "glue" and grout on her outdoor projects, so I followed her lead on my skyscraper towers. If it is not polymer reinforced (I can't get the Maipai brand at Lowes that people here talk about) or what ever the phrase is, you should get the additive in a gallon jug. I use it half and half with water per my dh's advice, though if I was mosaicking a bird bath I think I would use it full strength (with no water).

Hope this helps, I'm really just learning myself.

Kathy

Sorry for the typos in my post. I did it twice! I meant Thinset, not thinnest!

Y'all are right about the grout not being an adhesive. If you want to avoid grouting, which I have started doing cuz I can't get down on the ground and work but a few minutes at a time now, I use the push and sqush method. A goodly amount of polymer modified thinset and just push your tess into it so it comes up on all sides a bit. It works fine for some projects - not so much on all projects. I'm gonna use it more and more cuz I hate grouting period.

So Leasa, what happened. Are you making your next project?
Kathy

Thanks for asking! They mostly all stuck, I think because the grout squeezed around the edges. 3 popped off after some rough prodding. I used the 527 to stick them.

I have several more projects laid out but I'm going to wait until I get the thinset. The seaglass looks a WHOLE lot better--just as good as my jewelry! So the press it in method is what I need to use, or the stick it with thinset. Just so I do not spread the grout over the top of the glass.

I have been working hard to get the grout off the dragon, my thumbnail seems to be the best tool, but my elbow and shoulder do not really like it so, I'm just doing one or two pieces a day, it will take a while, but I will get it to where I'm happy with it, In the mean time I have painted a board with a back ground of the Bay and neighboring island and glued seaglass, shells and a bit of drift wood. Looks pretty. Course that is not a mosaic.

We'd still love to see a picture. Especially since you could just put it in this thread, which IS about mosaicking. You must get a lot of seaglass way up there. I've only ever found a few random pieces in the Harpswell/Casco Bay area. My mother in law had enough to fill one of those lamps, but that was many years collecting.
I'm going to treat the seaglass on my moth before grouting, so I'm glad you brought this all up.

Kathy