PU foam VS Core-Cell or other?

[yokebutt]

I didn't say I actually like solid skins with stringers, I just offered it as an alternative to those who are incapable of building quality sandwich panels.

Yoke.

[ARPRO®]

Core material currently used are SAN (styrene acrylonitrile, the corecell) and PVC (polyvinylcloride) which have similar mechanical properties although have different chemical composition.

You will find a new material coming up with very interesting properties and a way cheaper than the aformentioned materials. Expanded polypropylene.
It has different mechanical properties (fully elastic behaviour), lower shear and compressive stiffness than PVC and SAN, but higher compressive strength. Its qualities are appreciated if you look at the sandwich as a unit. A hull cored with EPP guarantees about the 60% of the static performances of SAN and PVC but much better impact properties, with better damage tolerance. Delamination does not take place at all.
If you use polyester or vinylester resins in hand lay-up you get an adhesion that is better than the other core materials. If you think of vacuum-bagging you may have some problems as the styrene is trapped and prevent from the adhesion.
I personally carried out some comparative tests on sandwich panels cored with diverse material, and the impact performance of EPP is stunning.
The best EPP on the market is made by JSP www.jsp.com.

[War Whoop]

I worked with the PP Foam 16 years or so ago not even close to what I was using.

Maybe for floatation considerations.

[buckknekkid]

where ya bin hiding~~~~~~~~` recognize 121?