High Performance Foam Blanks for $5 !!!

Rice is the most consumed food…are you aware of how much research has gone into rice?  LOTS!

In fact, there has been a lot of research in puffed rice (like Rice Krispies cereal).  Mulitnationals like “General Mills” have invested a lot money in finding a way to make people think they are buying something of content, but really it is just air.  A box of rice krispies or a bag of puffed rice cakes, has about $0.10 of rice in it, the rest is air, and they sell it for $3.  Brilliant!

Turns out that after 1 billion years of trial and error, nature has created fibers that have much better strength/weight ratios than Polyurethane or EPS.  Surprised?  Consumer puffed rice can come as low as 4lbs/cuft, while being up to twice as strong as PU or EPS of the same density.  If General Mills wanted to achieve 3lb/cuft puffed rice, they would have, but I’m sure they were unaware of the arbitrary foam standard that has been esablished by the surf industry.  Anyway that leaves something for an entrepreneur.


Here’s how you make a high performance (and ecocentric) blank for $5.  Start by making rice krispie treats, mixing 50/50 puffed rice and PU foam(before blown) .  Improve your process and you’ll eventually get up to 90/10.   The rice (if you source in bulk) will cost you a few dollars and so will the PU foam (at 90/10).  If I wasn’t working on my Phd, I would be doing it right now.

My napkin calculations suggest that the strength advantage of puffed rice = less glass requirement, and therefore you can achieve the same classic surfboard weight, while possibly being stronger.  Another benefit of natural polymers (rice), is that they be taken to 400deg Farenheit.  That means you can start to do cool things, like autoclaving and using thermo-applied thermoplastics, which currently can’t be done–it may be important to use thermoplastic laminates (which don’t crack) because a leak would significantly damage the adjacent rice puff (the closed cell PU foam that surrounds the rice puffs will prevent further permeation.

Any takers?  Do what you want with it.

Here’s a C2C model I developed:


And if it snaps, breakfast!!! haha.


And if it snaps, breakfast!!! haha.



I think you meant, Snap, Crackle.....POP!

I love these quriky/borderline feasable threads.  Chiming in on this on for two reasons:  Years ago I built a full sized hollow deer out of puffed rice coated with epoxy, 3/4 - 1" thick walls. Mix ratio was pretty low like Ben mentioned (still have the notes somewhere). Yep, strong and very light.  Only concern I would have about using it as a core would be rupturing some cells and getting some water in there.  That salty starch would never dry. 

Second reason is because I remember seeing an obscure thread here on Sways about someone having made a 'rice crispy blank', someone else commenting on their dried mushroom blank . . . Anyone else remember this?

our own keith meilville already built one of these with his kids last year

ask him what happened…

Actually for a thread thats trying to make factual claims, this one looks like it

was pulled out of his butt.


>Turns out that after 1 billion years of trial and error, nature has
created  >fibers that have much better strength/weight ratios than polyurethane or EPS.


Snap, Crackle, Pop.


Are you questioning the “billion years” statement or that cellulosic fibers have better strength/weight ratios than polyurethane or polystyrene?


The first statement is not worth arguing about(has nothing to do with the purpose of the post), the latter can be looked up on the internet in 5 mins, or proved in an experiment this very instance.


well...how much do the raw materials for a poly/epoxy blank cost in bulk prior to their being mixed and poured?  $5.00...or less???  how much of the cost of a blank right now is labor/fixed overhead/profit?  i'm not in the industry, i don't know. but i'm not sure there would really be a cost differential to be gained in rice vs chemicals.


and then.  i'm also not a chemical engineer, so i'd be interested to see if rice can be reduced to a cellular level compatible with the chemicals used to create a polyurtehane blank, so that it would not be a rice krispy lump, but rather a smooth pour with a cellular consistency lke that of epoxy or poly, but with the claimed superior strength of rice.  you know what i'm saying?  that the rice would then be able to substitute for whatever it is in the mixture that allows the cells to be formed.  see how ignorant of the chemical process i am?


i'd think you could use rice in combination with but not instead of, as rice might/would alter chemical interaction required to turn the liquid pour into a solid.  but what would be the benefit if the rice could not substitute for the chemicals.  it would just be an additional cost.


i got some 2 part pour foam that i would use and would make a mini test mold to see how it works, but not to just add some rice krispies to the mixture.  what would that prove?


and then shaping the rice puffs??? probably have to spackle the whole thing before glassing.

on the other hand, if the entire cellular structure was based on polymerized rice then you might have an organic based blank..but doesn't bio foam do that already?


pizza dough

go getum Jay

peterg hit the nail on the head… the problem with using puffed rice/rice krispies (I tried the name brand, myself) is that you end up with a whole bunch of 2mm bubbles bound together… even if shapable, the porosity of the result made it pointless.  I suppose it might work as a light inner core but other than that, I didn’t even bother to glass the test panel I made.