There are, according to the manufacturer, two ways to edge a wall in glass block: one is with mortar, the other, with channels that you purchase. The guy at Lowe’s recommended the channel approach as sturdier, so that’s what we did.
It’s really not that hard. First, you attach the channel to the wall with screws and then paint the screws white.
Then, you squirt a thick bead of sealant into the channel and place the block.
Then, you create the equivalent of a glass block sandwich – thick bead of sealant, spacer, thick bead of sealant, then another glass block.
There were only two things that weren’t on the instructions. The first was cutting the channels and (since we used only the edge pieces, which are rounded), the spacers. The guy at Lowes said you can do it with a chop saw, which we did, but definitely wear goggles – the plastic shreds and chips fly everywhere.
The second was the rubber mallet. The blocks are slightly wider than the channel and tend to get out of alignment – by the time we were five blocks high, we were going crooked. The sealant takes about 20 minutes to dry so you do have time to realign, but the rubber mallet really helped.
The other thing that’s really important is the measurement of the wall. The blocks are 7 ¾ inches (even though they are called 8-inch blocks) and you can’t cut them, so your wall needs to be the right height and length. We had to build up the floor a bit (we just used a scrap of trim) to make the math come out right.
Next step – the mortar.
By the way – Lowe’s stocks only Dow Corning. They’re nice but the edge and corner pieces cost a fortune. I found Glass Blocks Unlimited on the web and they were super helpful. They stock a different brand called Mulia. It’s “almost as good” as Dow Corning and the edge and corner pieces are MUCH less expensive, so that’s what we got. And the shipping wasn’t bad!