Tempered (Crash) Glass Help

I'm fairly new to Mosaics, I've just been working with them since November but I'm hooked! I've never worked with tempered glass but now I have an abundance of it I'd like to give it a try. We had a large patio table on the deck that had glass with a fern impression on the back - it "was" beautiful :( In December heavy winds picked up the umbrella in the middle and with the frigid temperatures when it landed on the table there was a loud crash! As sad as I was to see the destroyed table it softened the blow when I realized I now had an ample supply of TG to use for mosaics :) I've searched through the threads and unless I missed it I can't find what I'm looking for? I seem to recall reading something about gluing the back of the TG before working with it. Are you supposed to apply the glue "before" you smash it? If so that's obviously not going to work for me since Mother Nature took care of that! I've scooped up all the pieces, most were pretty small, but I'm hoping to be able to use them for a "glass on glass" project I've got in mind to keep me busy this summer. Any help or advice would be appreciated - thanks!

Debbie