PU or EPS: Which One Is Best?
When ordering your next board, you are going to have to make a decision between going with standard PU/PE (polyurethane blank, polyester resin), EPS/Epoxy (Expanded Polystyrene, otherwise known as Styrofoam), or XPS (Extruded Polystyrene Foam).
Haydenshapes - Hypto Krypto and DHD - Black Diamond with PU blanks compared to their EPS construction versions.
Brief History of Surfboard Blanks
In the late 50’s Hobie Alter began playing around with different PU formulas to make a blank that would be easier to shape and produce than using Balsa wood. This became a turning point in surfboard manufacturing as the foam was much easier to shape and more constant to work with. The weight of boards dropped and the performance levels went through the roof.
Soon after that, Hobie had a full blown factory pumping out PU blanks and had appointed Gordon Clark to help with the endeavours. Eventually, Gordon would take over the blank manufacturing so Hobie could focus on building surfboards, and as a result, Hobie Surfboards had become the first mass manufacturers of surfboards paving the path for the surf industry as we see it today.
In 2005 Gordon Clark's Foam factory abruptly ceased operations due to increasing pressure from State and federal Environmental Protection Agencies (EPA). With no other dominant PU manufacturers to quickly fill the void, EPS made a jump forward as a viable option for board builders. As they had to wait and test through the issues of new PU foam formulas from new blank manufacturers.
Although EPS had been used by some since around the 70’s or earlier, it took this major blank disaster to get the majority of board builders to start using the alternative.
Left (top): Gordon Clark in his Foam Factory, mid 70's. Right (Bottom): Clark Foam 2005 after the demolition.
This day in age, however, EPS foam blanks have become a regular option for most of the surfboard industry. The performance attributes, though slightly different than PU, are just as notable.
Now, even the top level elite surfers will sometimes prefer to use EPS/Epoxy boards over PU/PE for certain waves or conditions.
They are both great options, but for us regular surfers who can’t afford an endless quiver, we need to think about these differences and make an informed decision before ordering our next board.
PU / PE Boards
PU as a construction refers to a surfboard built from a Polyurethane blank with Polyester resin, whilst PE refers to a Polyurethane Blank with Epoxy resin.
These have long been the standard for most brands, and are the most widely and affordable options still out there. Due to the foam's weight and density PU / PE boards sit a little lower in the water, helping to keep your rail under, giving you a nice “knifey” feel when slicing through the wave's face.
They are also a little heavier so when you’re surfing those “not so clean” days, they will handle the chop better, with less bouncing around. Sitting lower in the water also has its benefits to barrel riding, providing more hold in hollow waves.
PU boards have a lively flex pattern, which shapers try to mimic on EPS/Epoxy boards through different reinforcements like carbon strips or parabolic rails.
PU / PE is cheaper
This is often the determining factor for most people. EPS constructions are more expensive for the manufacturers which results in them costing a little more than your standard PU.
Diagram of the Haydenshapes PE Construction.
EPS is a popular option for many brands these days and for a number of good reasons. One of the most notable differences between EPS and PU is the weight.
EPS foam is much lighter than PU which makes for a great option for the surfers that love to take it to the air. Lighter boards are easier to whip around quickly, this extra sensitivity makes them great for progressive surfing on waves that let you perform quick snappy manoeuvres.
They also have a more buoyant feel to them, as if they sit a little more on top of the wave. This can be beneficial for building speed faster also making it become easier to glide through flat sections. The combination of these factors has made them a great option for small wave boards.
Want to see more EPS surfboards? View our selection of EPS Foam surfboards to find one that suits you.
Diagram of the Haydenshapes Future Flex Construction utilising a stringless EPS blank and carbon fibre.
EPS is more environmentally friendly
Unlike PU, EPS be recycled. Making it the obvious choice for sustainable surfboard manufacturers and surfers alike.
You will find this foam in the core of all eco-friendly surfboard constructions. Often combined with bio resin and fibreglass alternatives such as flax cloth.
For more eco-friendly alternatives, see our Sustainability Page.
Epoxy resin is the only resin that can be used on EPS foam. It’s a little stronger than and also more flexible, allowing it to snap back into shape better than Polyester which is a little more brittle and can lead to cracking.
Extruded Polystyrene (XPS) Boards
XPS is produced using the same base materials (polystyrene) as EPS. However, the difference is that it uses ‘extrusion’ to fuse together small plastic beads of polystyrene. The molten base material and additives are then pressed and cooled to form sheets. Compared to EPS, XPS foams have a more closed cell structure which makes it stronger and ideal for high performance surfing.
Structurally, XPS foams have cell structures that are so densely packed that it greatly ‘minimises’ and not totally eliminates the absorption of water. Both EPS and XPS are permeable by water molecules and not considered a vapour barrier.
EPS versus XPS Boards
XPS boards offer you all the advantages of EPS boards but come on top in terms of strength and their water absorption resistance properties. EPS has better structural integrity which protects it against hard impacts and prevents dings to your surfboard. If there’s one downside with EPS, it is the cost of producing these boards, making them the priciest of all surfboard options.
Julian Wilson boosting on his JS - Air 17 in PU and Air 17 Hyfi (EPS Construction). Same board, different constructions.
Which One Is Best For You?
Now that you have a better idea of what attributes the different blanks possess, you should be able to make a better decision when ordering.
All brands have different Surfboard Construction types you can choose from.
Our goal is to help inform you so you can make the right decision for your next custom surfboard and make sure you are as stoked as possible.
There is a lot more that goes into surfboard constructions, so check out our related articles on Surfboard Bottom Contours and Surfboard Shapes, Tails, Rails and Noses.
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