Originally Posted By: sd_101
For reference, what is the foam density of styrofoam cups? What about coolers of yesteryear?

Serious question.

everyday PU shortboard blanks about 2.2 lb/cubic ft (pcf). Superlight team PU close to 2 pcf.

Wall insulation EPS from Home Depot is 1.0 pcf. This can't handle much compression Vacuum pressure https://www.swaylocks.com/comment/94770#comment-94770

I found about half what the manufacturer said here https://www.insulfoam.com/wp-content/uploads/2014/04/12001-Wall-TDS_WEB-REV8-16.pdf

However I encapsulated it in super strong divinycell or corecell sandwich and obtained a light bullet proof build.

So FW's Helium of 0.8 pcf is extremely light. Which as I said leaves plenty of room in the weight budget for a super strong sandwich, however they compromised a bit and went for a superlight build. On paper should still be strong though.

So on to your question of Styrofoam cup and cooler - wild guess just from looking at the bead size maybe 1.5

Strongest builds are very light EPS and heavy/solid sandwich skin. HS say they use a hi density EPS for their futureflex build. They don't say exactly what, but if it is something like 2.0 then it is not possible to produce a bullet proof build. When I enquired about futureflex on my Chilli thread Hopeless and Havoc said something to the effect of rides decent, not bullet proof.

It looks like the new build (surftech/cobra/domestic) is going to follow the same paradigm. From a couple of days ago - new rail tape, so same rail stringer methodology.