I have a premanufactured front deck assembly...but it doesn't fit my fuselage...so I started from scratch. I did a couple of prototypes before getting to the final copy...the first one was with cheap polyurethane insulation from Home Depot...it didn't work real well...I couldn't get all the Kraft Paper off the foam, plus it had a lot of voids. My second attempt turned out really nice...however I realized that I was planning on putting a header tank under the deck...so the Styrofoam I used wasn't going to work. The third one burned down, fell over, then sank into the swamp...but the fourth one stayed.
I started out by covering one side of 1/2 inch polyurethane foam with deck cloth....then I scored the raw side several places.
I built a frame to wrap the sheet around.
Trouble is...the fuselage is curved in several directions...so it didn't exactly lay right down...I had to bond it. I had the bright idea of using superglue because it's supposed to dissolve with acetone...it didn't.
I then put the assembly in place...clamped it down...and finish sanded to shape. The mistake I made with number 3 (you can see it on top of the canopy in this picture) was to try to micro the joints first then glass. I couldn't get it to sand right...so filling the joints and glassing the top in one step was the trick.
I put the canopy in place and foamed under the edge...starting to look pretty good here.
Here is the front deck as prepared to mount the canopy. I will cut the canopy portion off once attached.