It will work but I strongly recommend you practice first.
I hate G glue myself even though it is great glue. It foams up and is really difficult to remove if you get it one the surface but I have a friend who loves it and can do invisible mends easily.

This is my favorite glue. Sort of like Gorilla glue but doesn't foam up as much and really holds tight. After repairing, you can use a slurry to cover the cracks. This "oops" happened last summer and the planter is still holding up perfectly.
Jo

Here is a link that might be useful: great glue

Jo, thanks for the new glue idea. I'll look for it. Being the impatient sort, I went ahead and tried the GG. Bought it 2-3 yrs. ago and hadn't tried it yet. Looks like it worked and it filled in the small gaps that were there. If it ultimately fails, will try the other. I'm psyched to try new sculpture incorporating glass mosaic, so want to get this finished up.

GG will last about three years if there is no air in the bottle or you can freeze it.
It likes moisture so if you dampened your cement a bit before using you should have a very strong joint.
GG is very strong just can be messy.:)

I used GG to glue wooden finials to cement spheres with flat tops that I made with those little carnival fishbowls.
(I was making fence post toppers). The glue worked really, really well. I didn't clamp them together and when the glue bubbled up the finials drifted and now they're attached forever. Only one is badly askew. I'll be sure to clamp when I make a replacement.

Deb

My fav GG story was writing to the company to tell them that I used GG to repair the broken fingers on the concrete hands in the garden (hands were made by filling latex gloves w/ concrete) ....WELL - they missed the concrete part - were stunned to hear I had repaired broken fingers with GG - and sent me a GG t-shirt as some kind of reward!

Still giggling about that everytime I hear the name GG mentioned.

Vicki

Susan, You can use Gorilla Glue. I've also used Liquid Nails and mortar mix.
wannadanc, That is too funny.........what have you been up to, haven't seen you around. Billie