Is anyone using the type of foam that bicycle helmets are made of. It is very hard stuff.
That is EPS foam at about an 8 lb density. Not something you would use on a board at that density. It does show how impressive EPS can be. We use densities close to the low end.
The stuff appeared to me that it could provide all the stength needed with just light coating for a finish.
They used to sell boards under the name Aqua Toys. This was back in the 80’s and those were just high density EPS with aluminum dowels inside for strength. They were not high performance but they were adaquate for beginners.