I would suggest doing a search on the garden junk forum: there've been several discussions there over the last few years about exterior glues, etc. Regular glue gun sticks would not work...

I did quite a bit of research before repairing all of my clay/terracotta pots in January 2014. I used E6000 Industrial Strength Adhesive. I used the craft version of the glue and I think I may have purchased it at Michaels or maybe Big Lots. The glue has the following desirable properties for this type of repair:

• Clear
• Flexible
• Waterproof
• Non-flammable

Just kidding - that last one wasn't a requirement. :)

I didn't have any pots that were completely broken in half, so I don't have any experience putting two or more parts back together, but I had cracks running through many of them. I used a whisk broom to clean them thoroughly of all dirt and debris, inside and out. I brought them inside and did my gluing on newspaper on the kitchen counter. I glued along the crack both on the outside of the pot and, a few days later, on the inside of the pot. I used a toothpick to spread the glue when necessary. I took several days to glue them all, on both sides, the entire length of each crack. I ran the glue several inches beyond the visible end of the crack, too.

All of the pots held up perfectly through 2014 and so far, into 2015. The glue does dry a shiny clear, so if you look closely, the glue is visible even though it is clear.

I have learned to carry all of my larger expensive pots with two hands. With one hand, you put pressure inside the rim/pot and a cracked pot may break. With two hands, the pressure is on the outside of the pot and it is far less likely to break. Yes, it takes longer to carry them from here to there, but it depends upon how much you like your pot. :)

Good luck!

Carol in Jacksonville