Would One of these work as a dome?

[jpawlak]

I was at Meijer last night, looking for batting helmets (unfortunately all they had were helmets with like, scallops, and holes in them), and saw these for sale for $10:

And I thought "Hey, maybe that'd work for a dome!" What do you guys think? Granted, I'd have to fill in the hole on the top with some putty, but for $10...

 

[SD68]

That is what I used for my dome but it is too small as is. I had to cut it into quarters and spread it both lengthwise and width wise by approximately 1" with styrene strips or you could use sintra. Look under "New batting helmet bucket".
Steve

 

[GrottyFurball]

One of those will work but it will need to be made longer and wider. Take a look at skateboard helmets.