I also used the blue foam, in fact I replaced the entire door with new materials, only kept the outer Fiberglass skin and the aluminum frame.
The Blue foam was thinner than the original foam, So I added a inner layer of luan to make up the difference.
My layers were:
1. Original Fiberglass Skin
2. Luan
3. Blue Foam with Cedar strips down the sides
4. Luan
5. Inside Surface (I got a replacement from
Lowes but it was fiberglass not vinyl)
With all these changes including the extra layer of Luan I was also worried about the weight increase, thinking I may need to get stronger gas struts, but the existing ones handle the weight fine.
I don't see the advantage of the extra stile myself. I considered adding a rail across the bottom, to help eliminate sag when in the up position, but ended up deciding that the aluminum frame was probably sufficient for that...
I used Gorilla Glue for most of the Glue up. I liked the fact that it is waterproof and expands to fill any gaps/cracks, but is a little thick and not the easiest to work with. I needed a lot of clamps... If I was to do it again, I might not use it again..
I only siliconed the outer edge of the frame to the fiberglass, There are drain holes in the frame, and figured that if any water was to get in I wanted it to get out. The silicone is just to keep the water out particularly when the door is in the open position, as a thin layer of water will sit/pool on it.
Basically I have a brand new door... I did price out a replacement though the dealer... came out to approx $1200 :E after shipping...
Good luck with your project!