Click here for the official guidelines from the Boy Scouts of America for the Composite Materials Merit Badge.
Composite materials appear everywhere in life, not the least of which is in plastics. The 5-gallon buckets, atrium drains, and PVC pipe used in our self-watering bucket containers are all made of plastic. In fact, it is the plastic nature of the containers that keeps pests from burrowing up into their soil and keeps the water in their reservoirs from seeping away.
This badge requires you to complete two projects, one of which you can select on your own with your Badge Counselor’s prior approval. The other project must come from the Composite Materials Merit Badge pamphlet. You may wish to explore using a container garden as your second composite materials project, presuming your Badge Counselor approves, only with an orientation towards how the composite materials are used to support non-GMO, organic container gardening as opposed to focusing on the gardening or community involvement aspects per se (though how these elements dovetail with the requirements of this badge is a necessary part of your discovery and discussions).
The safety of a project involving composite materials can vary depending on the nature of each project, but container gardening is rather safe compared to projects involving the mixture of extremely hot and potentially toxic chemicals. Finding a safe place to conduct a container garden project should not be all that challenging.
Your container garden can give you some ideas about how composite materials can be used. Where this badge requires you to compare the similarities and differences between composites and wood, aluminum, copper, and steel, consider the properties of the plastics used in your gardening materials that make them suitable for container gardening that may or may not be properties they have in common with other types of materials.
Your example of how composites can be shaped and used for a specific application are right in front of you in the form of 5-gallon buckets, atrium drains, and PVC pipe. Where this badge calls for an examination of how composite materials are made, including thermoset resins and thermoplastic resins, your container garden materials again provide actual real-life applications of these technologies.