Too light? Wrong Material?

Hey, first time post here. 

I’ve been keen to try shaping my own boards for a while and recently got stuck into shaping my first one. The catch is the EPS im using comes from a construction site, it’s not packing EPS, it’s construction foam, comes in large light blue slabs. I’ve shaped the board to my liking but im genuinely worried about how light it is. I know EPS is considerably lighter than PU but this board barely weights a thing. If i hold the board in the air and drop it, it’s almost “floaty”. Before i glass the board i’d like to know if this thing is made from the wrong material or if EPS boards really are that light when you’re shaping them, pre glass. It’s a 5’5. it’s also got a tonne of flex through the center. Am i wasting my time with this material? or is this correct for EPS foam?

I also have a proper PU blank handy which i plan on shaping but i’d love to be able to glass the first thing i shaped. Just want to know if t’s right. Thanks heaps :slight_smile:

What no pictures??

Sounds like you shaped a Dow Blue EPS Stringerless blank.  Yes a little stringerless 5’5 will weigh about the same as a sheet of TP.  I would be more worried about a six inch wave snapping it.  

Ahh, so it’s no good then? Best to bin it?

No.  Glass it.  Just put some Carbon tape down the center or around the rails.  Vector Net the deck, bottom or both.  A lot of people Make occasional boards out of Dow Blue.  Just take precautions (with any of those “Construction Grade” foams.  People sometimes use Dow Blue in combination with regular EPS and other construction grade foams.  I’m not an expert on Dow Blue, but I’ve heard that it is has more strength than regular “Grade” EPS.  Maybe somebody with some real knowledge will chime in here.

Just glass it with double layers top and bottom, wrap the rails with all 4 layers of glass. The board will be strong. Be sure to use epoxy resin with EPS and XPS.

@ OP

Dow blue can be used if you have the right density foam.

What was printed on the foam sheet before you shaped it?

I agree with shark country, use a symmetrical glassing schedule top and bottom.  

The FG cloth weight used depends on foam density.