EPS vs. Polyurethane: Flex, Feel, and Float.

Looks like I somehow missed your post! This was one of the first things I forgot about when I went around talking to other shapers. I’m sure I sounded like a real idiot when I kept talking around the subject of volume but never addressed it properly. Thanks for bringing this up, remembering how basic physics work is the first step to achieving what I’m looking for!

So I’ve heard from a few other shapers! Help me see the light. 

This is good information. I haven’t had a chance to do a side by side comparison on my own, all I’ve had to go off of is what I feel when riding and what others say they feel. I may have to play with thinning out certain areas of the board to get them to stay flexed when needed and not have an immediate spring back. I will check the archives for more information on different stringers and how they affect the board. Thank you!

Your premis is self defeating. Why would you want to build an EPS board to be a poly board. The only thing would be to sell it to someone who liked poly boards. Change the game reinvent the shape and glassing schedule to get to a new peridyme. I love the new materials because I can start over and learn a whole new way. Lighter is good if done right. The one drawback of EPS is the sucking of water when dinged. I use innegra cloth to try to help prevent dings that leak water in and to keep the flex of the EPS and wood stringers(2). You do spend a lot of time making your own blank but we’re not on this forum to avoid doing something ourself. I really like perimeter stringers and they are hard to come by or expensive to buy. 

This! I make all my boards epoxy resin over poly blanks. Best of both worlds. These days you can get poly blanks in super low densities; so you can get pretty close to EPS lightness if you want (US Orange, etc.). I use a poly glassing schedule (4E or S on the bottom; double 4 E/S on top for shorties). Part of the reason I use Epoxy is I don’t want to stink up the neighborhood, but also it’s just plain stronger: no delams, no spider cracks, just dents. It’s more expensive but I’m pretty stingy with it. I can get 3 shorties out of a 1.5 gallon kit of Resin Research epoxy. So at $118 for this kit I’m at $40 per board for resin. If you want to play around making EPS blanks, have at it. But if you are trying to duplicate Poly feel, you are better off just using Epoxy over Poly.