Dudley Dix and foam

[Sand crab]

I was looking at a DD build and noticed that they use "regular" Pink Panther foam. I'm not in the market but it was one of the few cats made in the US so I thought I'd take a look. The ad says some pics are from other boats. The specs say:
Material: Composite: double skin on stringers with XPS core complete fiberglass exterior over integral bullheads vacuum formed with fiberglass and marine ply over Gurit structural foam. All exterior surfaces are covered in fiberglass.
Are only the bulkheads Gurit while the rest is regular PP foam? Is the PP foam structural? Do they bond to it?

I am not knocking DD boats. I think they are kinda cool. Perhaps he has a unique method of building. I read about building different fiberglass items with PP foam so it can happen. And by the way that foam is produced in many different densities that you never see at Home Depot. Anybody have more info?

https://www.yachtworld.com/yacht/202...ix500-8256046/

[Simi 60]

Ply foam ply

Not new, has been done in the past

. The unique complete plywood double skin construction of the DIX500 with 38mm-52mm 1 ½” – 2” of foam sandwiched between it, will save on cooling or heating costs and make for an incredibly quiet ride and assure hours of peaceful sleep at anchor.

https://crw-con.com/

[GordMay]

Gurit makes several different STRUCTURAL foams, for use in composite sandwich construction.
Gurit Structural Core Materials
➥ https://www.gurit.com/-/media/gurit/...e_brochure.pdf

➥ https://www.gurit.com/en/our-busines...core-materials