Awhile back, we worked on bottle cap murals. I was so excited about this idea after seeing it over at Art Grange. We spent a lot of time playing with our collection of caps, making various creations. While we played with the caps, I also started to test out various options for glue. The original murals used a screw to hold each individual cap down. I knew that some of our crew could assist with securing the caps, but thought that finding a good glue would make the project more child friendly and they could complete it in a faster time frame. In the end, I found that the tub and tile caulk/glue would work great for our outdoor murals. I tested it to see how it would hold- and I even left it out in the rain to make sure that it would hold up in the weather. What I forgot to test.... is the fact that we live in the U.P. of Michigan........ and it gets COLD- freezing COLD in the winter.... And...