I always thought it was the out side of the fabrication you need to place in a mould or else you'll spend 3days and a couple of hundred buck makinging it look good until it starts to craze. fiberglass should be saved for boats.
sorry I have no flash picture or such but my rig should be on the road by 24th march(legally)
I'll send you a pic of me beating my snorkle with a sledgehammer. or when i tied my 60 inch hi lift to it on a trail run,
Then there is that PITA when a 3 inch branch gets caught between the truck and the snorkle and you have to cut it with an axe...
I don't disagree that you can fibreglass strong...
but it would have to be reinforced with kevlar, and have numerous backing plates to get anywhere near the same strength of a simple welded stainless snorkle...