technical data

is PU more flexible than eps?


is poly more flexible than epoxy??



I don’t know much, but… when you’re talking about flexibility, are you talking about simple elasticity, deflection, flexural strength, flex return, etc.??? Other factors change the flex of different foams, too… like shear strength and fatigue…over time. So how each holds up under the stress and strain of use is a big factor. And are you talking about equal densities, EPS and PU, and same glass schedule for epoxy and PE?

I’ve found that 2lb eps is very similar in flex to standard PU. I don’t make any accommodations for differences in flex based on the properties of the foam. This is all just my sense of things. I don’t have any numbers.

oh, tnx


I think at scientific/tecnic number data between eps/pu flex.


I refer to same density of foam, of course.


final question is same ever “what’s best foam for surfboard”???


... "what's best foam for surfboard"???


Now that sounds like the best way to start a cat fight, on this forum!   A  highly subjective topic.    For me, ''the devil I know'' is PU foam.   But that's just me.   Hell, for that matter, I really like balsa too. 

If you search long enough you will find the numbers you are looking for.

I’m more like what they said - What ever I like, and I like making my own blanks, so I use eps, and some xps.

apoligize me, Thraikill, I’m in difficolt for good understand english idoms…“cat fight” means an “absolute question”? Is it most important question like “Is born first egg or kitchen”??

Is not exist a unique answer to question?


Sorry… I’ve a limit of shaping skin like all, in Italy

shaping in peninsula is a new activity and i Hope find some tips


tnx to everybody



PU foam is easier to shape, if you do not have much experience. It is the industry standard, so it must work well. I shape EPS. It’s lighter, and I can glass it heavier and get a stronger board for the same weight. As for flex, the extra glass will make it more rigid. A slightly thinner board will get some flex back, or you can use a thinner stringer, no stringer, or a fiberglass stringer.