Part Two: Make the Foam Thrusting Head:
Get out the vinyl trailer hitch sleeve.

Using blue camping mat foam or whatever type of closed cell foam you have, cut out three to five 2” diameter circles of the foam depending on the foam’s thickness (you need to have at least 2” of foam between the tip of the javelin and the rubber stopper) and stuff them into the trailer hitch sleeve. Do not jam them in too tightly, they will seat themselves once the tip is placed on the javelin and you want a little give. If you have a flair for neatness and extra performance, on your last foam circle cut out the center of it to a diameter of about 1” so that it looks like a ring. This will allow your rubber stopper to seat inside the thrusting tip head and give you greater stability and less lateral movement when you stab someone with it.