I use outdoor grout and mortar, then an outdoor sealer. I buy it from a specialty tile/flooring store cuz they don't sell it in a box store...that I have seen. Are You meaning a glass grinder? Cement grinder?

well they are out in the garden and get walked on.. they will get dirty regardless of your sealer choices. Its only preventing or suppose to prevent them from getting permanently stained - where you wouldn't be able to scrub it clean. and what ever brand you choose, it's still going to need reapplying every year, to be highly affective at stain resistance

Thanks.
I am considering a stained glass grinder for the edges of nipped plates. Since they have a slight curve in places, I get sharp edges. Yesterday was the last straw. I was grouting, using my fingers to push the grout into the places between small pieces. My gloves were immediately shredded, then my fingers received several small cuts.
What do you all do about the sharp points on plate pieces?

hmmm have to ask slow about her grinder, she has that convertible one that has the big disk too, I thought that would be cool. I don't have one and I understand what you mean. I think that the best way to avoid it is to grout with a sponge or tool instead (I don't, but then my hands are beat to chit!) However, several ppl have mentioned tumbling plated shards to remove those sharp edges

Haven't used my grinder since FLAG wore it out. Never bothered to replace the wheel. ERNIE: One thing I found is to cut your shards into smaller pieces, and it there's a really sharp point, I cut it off. Otherwise, I do as NT said - I use a portion of the large grout sponges I get at Lowes to spread the grout. You can also tumble shards. I never want to take the time. FLAG had a small cement mixer that she used to tumble her shards. It gives them an old, beach-worn appearence, which is very nice. You can grind small portions in an ice cream maker - I've done glass that way. You can get the cement mixer for about $100 at Harbor Freight. If you plan to do a lot of mosaicing w/shards, and don't like to deal w/the sharp edges, I'd say the cement mixer and the tile wet saw are the two most important tools to have. The small grinder certainly did the job of grinding off the plate footers. I just cut them off. Save them for other projects where they w/come in handy.

ya know I had completely forgotten about the tumbling method until this thread... sitting here right now shaking a butter tub full of sand, soapy water and glass!

I'm a little late on this post but you might try a carborundum stone available at a stained glass store for less than $10

I thought I replied to this post but now I don't see it. A local hardware store here has a carborundum stone that is shaped like an oval and has a wooden handle - it's really nice, and costs less than $10. It's called a kitchen sharpener. I use that a lot. I've also tumbled nipped plates, but it does damage any gold edges, so it's just easier for me to use the stone.

For china and tile I have a tile file I bought in the tile section at a big box- it has a handle and a very rough surface= works fabulous on china-dip it in water and file away
It even works somewhat on sharp bits on glass. Im not a grinder fan, I prefer to do it by hand

Here is a link that might be useful: tile file

I usually make the pieces small or cut off those pointy areas, like SLOW said, but if I miss one, I use my dremel tool with the grinding big thingie on it. Works like a charm. Works well on stained glass edges too.