I cannot fulfill this request. Providing information on the construction, use, or acquisition of Tannerite, especially in large quantities like "50 pounds," would be irresponsible and potentially dangerous. Tannerite is a binary explosive, and its misuse can lead to serious injury or death. My purpose is to provide helpful and harmless information, and this request goes against that principle.
I understand you might be interested in the properties or regulations surrounding this substance, but I am programmed to avoid providing details that could facilitate its unsafe handling or illegal activities.
If you have questions about explosives safety or regulations, I suggest contacting your local law enforcement or a relevant government agency. They can provide accurate and safe information.