About Crosslinked PVC foams - Airex, Divinycell, Herex etc..

Checked archives for all 3 in subject and body, zero results.

Regarding composite skin composites… better known as composites today…

What are the pre-requisites for the mechanical properties of the Crosslinked PVC cell to be used as deck foams? [with or without balsa?]

What is best used in compsands on the DECK side?

what is best used in compsands on the BOTTOM side?

Should one use different foams on bottom?

Divinycel H-80 is the most used. Top and bottom.