I've used Laticrete and Maipei. My projects are all outdoor projects, so I need to use products that contain polymers for water resistance. Aside from that, though, I simply buy the brand they have at my local home improvement store. The two I've used have been a little different, but both have had plusses and minuses so they end up being a wash. I'm not familiar with Spectralock so I don't know what's making it more complicated than regular grout. The ones I've used, you just mix with water and mush it on. Laticrete, I had to buy special liquid to mix it with to make it outdoor proof. Maipei has the polymer in it so I just mix with water.

Thanks Loribee2!
The spectralock is made by Laticrete.

http://www.spectralock.com/

You buy the color in a milk carton and then a bucket with the two other elements in it. Sounds to me like Maipei might be the way to go. Is Maipei sanded or unsanded? What's the difference in the end with mosaics?

-ellie

Here is a link that might be useful: spectralock

I 'always' use only Maipei sanded grout. Unsanded is for grouting a narrow space 1/8" or less between tiles and is usually used in showers and bathtub surrounds. Sanded grout is stronger and is used for wider spaces between tiles. I use sanded grout on everything, even mirror tile and it doesn't scratch. I can't stand unsanded grout; it has an icky texture and shrinks when it dries.

Also I meant to add, you can use admix (mortar) for both adhesive and grout for outdoor projects. This will be the strongest grout of all. It's a little more messy to work with (sticky) and it should be mixed up in small batches because it sets up faster.

silvamae, could you be a bit more specific about the "admix (mortar)" you use for "both adhesive and grout for outdoor projects."?

Yes, I buy it at Lowes (and I'm sure Home Depot has it as well). The kind I buy is Mapei Ultraflex 2 Tile Mortar with Polymer. It is in a white bag with blue and gold labeling. I buy it by the 10-lb. bag. It is similar to grout (but of course much stronger) and you mix it like grout, with water. It is more sticky than grout (so more difficult to work with if you use it for grouting) and it dries faster, so mix in small portions and have a spray bottle of water nearby. A well-known mosaic artist and author recommends that, to use it as an adhesive, you mix it in a baggie, cut a corner off, and squeeze it out like you are decorating a cake. If you were to use it as both adhesive and grout for an outdoor piece, it would be as though your piece was set in concrete and it would last for many many years.

By Slivamae,
"If you were to use it as both adhesive and grout for an outdoor piece, it would be as though your piece was set in concrete and it would last for many many years."

Are you referring to the push and squish method here? I have not tried this but was considering it for some stepping stones I want to do. Some day.

The push and squish method would be one way to do it; I would like to try that myself some day.

But, no, I was referring to actually using the admix-mortar as grout. For a weatherproof, outdoor installation, first you mix up some mortar and use the cake-decorating baggie to apply it as an adhesive. Then after everything is dry and ready for grouting, you mix up another batch of the mortar (same consistency as grout) and apply it just as you would grout, spread and wipe off. This is where it's a little more difficult than using normal grout. The mortar is sticky and not as easy to clean off the tess, and it dries quickly so it needs to be mixed in small batches and applied and wiped off quickly. The reason for using it instead of grout is that it is much stronger and more weather-proof. I learned this from slowmedown who used to post here. She and several others, shrty411 and crackpotannie, I believe, all used mortar/admix for outdoor mosaics (as their glue) and slowmedown used it exclusively as grout, as I recall. Other adhesives may be fine for outside use on Vertical Surfaces since rainwater sluices off and rain or ice doesn't stand on a vertical surface, but for stepping stones, birdbaths, and the like, anywhere water is likely to pool and stand, the mortar/admix probably works best.