They have to be safe for impact against the head, and they have to weigh in at under 1.5lbs. We are Romans. If each of us had a javelin, we would be even more tactically devastating than we are now. This helps you at least as much as it helps Rome. You get to enjoy the luxury of reaching out to touch someone.
Construction is easy.
One javelin should take no longer than an hour. 1 Exacto Knife with a new razor blade. Once you have gathered the necessary materials, you are ready to begin. Wrap the ends of your fiberglass rod with duct tape. This helps to prevent it from pushing through the foam later.