OHMYGOODNESS!!! I can't even imagine a project that large. Nice way to do it, though, in small segments on the mesh (I haven't tried that method yet). I can't imagine a mosaic w/o grout, but if you don't like that look, there's no rule that says you have to grout that I'm aware of. If you choose not to grout, my suggestion w/be to not have grout lines, and fill in w/something interesting, such as rocks, pebbles, mirror, colorful stones, whatever you wish. (On a small mirror project I filled the grout lines w/beads, using black silicon.) The thinset is strong, so I don't know what you mean by protection - it doesn't need any protection. Please show us pictures. Sounds interesting.

First of all - I can't imagine doing a project that large - what patience you must have and what a vision - what is the theme, style, design of your wall? Any photos you can share of even a small section?

why do they say you can't use epoxy - I think you can tint epoxy but it also comes in a clear - I am thinking of the two part epoxy stuff. but using something like that - if you get it on any of the mosaic pieces, you may not be able to get it off.

I know what you mean about grout changing the look of the piece though - I felt the same way with the one small bowl I did but now I am getting used to it. I don't think you see as much of the mosiac pieces with the grout though - which changes the look of a mosaic piece. but on the otherhand, the grout seems to unify the mosaic as a whole.

Since the wall is outdoors (it is outdoors isn't it) I would suspect that with just the thinset - rain water would eventually be running between the pieces of mosaic - over time the mosaic pieces would loosen up?

Sounds AWESOME!!! Just leave as is, the mortar can be a "background" grout. Don't make us BEG for Pics now!!! We will you know!!! lol!

You will have to seal it. I am only familiar with LabCorp products, but I am sure there are others out there.
Ok, so now it's my turn to beg, PICTURES!

With using thinset i wouldn't think you'd HAVE to grout. Grout will strengthen the piece though. Mosaics with smalti are never grouted, but the pieces are really close together.
I like Slows suggestion of filling in all your "grout spaces" with more tesserae.

Thanks to everyone for your responses and suggestions (some very good ones, I must say). Bear with me as this is my first time using a forum like this so I will have to figure out how to send you photos - which I will do in the next day or two. After reading everyone's thoughts and doing some heavy thinking of my own, I have decided I will grout but I will do it very carefully and by going around every piece of mosaic. I know it will take forever but I have put so much time into this that I feel I must do it this way. I have come to the conculsion that I will use Laticrete's grout "Sea Glass" as it will go well with almost everything (I am doing an underwater sea scene with all kind of currents and wave-like sections along with various fish and a mermaid and seaweed and so on). I really feel the best thing to do is grout but I am definitely going to limit it. It is an outdoor pool but the wall I am doing is on the front side and will not get water to it - I will seal it after I am done, though, to make sure it is protected even more. To elaborate on the epoxy a little further, the tech at 100% Solids Epoxy Grout told me they wouldn't stand behind the product if it wasn't mixed with the color (which I wouldn't want to do) so that told me I should be careful there - plus epoxy would be really non-forgiving and not give me much time to work with it. So anyway, that's where I am, I guess. I'll be back soon with photos. Thanks for all your support. Leigh

Thank goodness you've decided to grout. IMO you w/NOT regret it when it's all finished. You sound like you have the patience to be very meticulous, so you'll be very happy w/your results, I'm sure. Sooooooo anxious to see pictures of this giant project.

Here is a wonderful site to help with grout color. You can put in some of your colors and see the grout with it. When I do a water scene, I like my grout to match the water. And then I find myself painting the grout on the fish & such, because I don't like blue grout on them. Hope this helps.
http://64.16.211.15/catalog/designer.php

Thanks to all of you for your help. Here are a couple of photos of my project in the included link.

Oops! The link didn't take - I'm new at this too. Here, I will try again.

Hmmmmmmm - pass the popcorn, please.

Got any Pepperment Patties?

Leigh, put your URL in the box just below the message field marked Optional Link URL, then write mosaic wall or leighs wall.. in the box marked Name the Link

pass me some popcorn!