Not following instructions

Burn, baby, burn...

 

I tried to follow instructions, but it seems leaving it in the oven for too long causes disaster!

 

At my first trial I preheated the oven, and it went quite well, though the first helmet I made was soft (and it's actually one of those black things since I tried to bake it again).

 

So I concluded that since the mold was thinner, I should have placed the thing inside the oven at a much shorter period of time.

Done