A couple of months ago I stumbled upon a discussion board that talked about and showed a small, lightweight reusable container made out of the necks and lids of two plastic soda bottles. I haven't been able to find that same post ever since, but remember enough about it to want to give it a shot for myself.
I started with two identical plastic soda bottles to make sure that they would match in size. I cut the necks of the bottles off using a small hacksaw making sure that I kept the large flange that would be used to glue the two necks together later.
Step 1: Cut Off the Necks
I used a vice to hold the bottles still while I cut through them. If you don't have a vice you can still do the same thing by hand,but be very careful and take your time.
Once I had cut off the neck of each bottle I used a flat file to smooth down the rough saw marks and left over plastic. The idea is to remove all the rough edges until you have a flat surface level with the large flange as this will be where you will glue the two pieces together.
Step 2: Smooth the Edges to Be Glued
Once I had filed the rough edges down and made sure that the edges were level. I used a little 600 grit sandpaper to smooth the edges a little more than what I was able to do with the file.
Here are the two sections of bottle necks ready to be glued together. I made sure that they were both clean and free from any rough edges that would stop good contact.
Step 3: Glue Pieces Together
I applied a small amount of super/crazy glue to the flat edges and then, using a small clamp, squeezed them tightly together to set. This type of glue only takes a minute or two to set, so after five minutes and a fresh cup of coffee I released the clamp to inspect my handiwork.
The final result is a small water-tight container with two ends that can be open via the lids. The total weight of the container is 0.5oz and it took about 10 minutes to make including the time to let the glue set.
Step 4: The Finished Result
This was a quick little project and a lot of fun to make. My seven-year-old son, Jack, helped me with some of the steps and watched throughout the entire process. He thought it was pretty cool to make a little piece of gear out of something else that we would normally just recycle. I probably won't be making a lot of these or using them for everything, but it is a useful little container and is very strong. I could see this being used as a container and float for a small fishing kit.
If you have some time and a few spare plastic soda bottles laying around, give it a try. After making this one I made another one with an additional flat piece of plastic sandwiched between the two necks that created a dual compartment container. I think I'll use it for salt and pepper!
This instructable was originally posted on Brian's Backpacking Blog.