PU or Epoxy: Which one is best?
When choosing your next board, you are bound to get a little caught up in whether you should go standard PU (Polyurethane) or EPS (Expanded Poly Styrene, otherwise knows as Styrofoam).
A standard question we get is Which is better, PU or EPS?
Since the closing of Clark Foam in 2005, EPS has taken a big step forward as for some it was an easy transition to the pitfalls of having to test out new PU foam formulas from new manufacturers.
Luckily, EPS has been used to some degree since really the 70’s or earlier, but it never really took off until the majority of the industry was forced to look at it as their options when PU suddenly went on the back burner.
Working on the deck of a PU Chemistry Surfboards model.
Today, EPS foam blanks are a regular option for the majority of surfboard brands and the performance characteristics (although slightly different) are just as notable at standard PU.
So much so that even the pro’s surfing at an elite level will sometimes prefer to use EPS for certain days or conditions over PU.
They both hold merit though and need to be thought about when you are ordering you next board (unless you want to order one of each).
A little bit of testing of the Carbon Wrap technology on DMS Surfboards.
First, let’s take a look at your standard Polyurethane foam board with fiberglass and Polyester resin (PU/PE).
This is the go to for most brands and the most widely available and affordable options.
In the late 50’s, Hobie Alter started experimenting with PU foam as an alternative to balsa wood. This was a pivotal point in surfboard manufacturing as the foam was way easier to shape, as well as more consistent throughout.
The weight dropped dramatically and performance levels skyrocketed.
Not long after, Hobie opened a factory dedicated to making these foam blanks and appointed Gordon Clark to help with the blank manufacturing.
Gordon eventually took over the blank business so Hobie could focus on making boards, essentially becoming the first full blown surfboard production company.
Asher Pacey easing into his bottom turn on his DHD Twin Fin in PU construction.
Not only are PU/PE boards a little more affordable than their EPS/Epoxy cousins, they sit a little lower in the water giving you a nicer rail game, with a “knife” like feel slicing through the water.
They are also a little heavier so when you are surfing those “not so clean” days they will handle the chop better, helping to keep you in the wave with less bouncing around.
If you plan on surfing nice hollow waves, PU/PE boards also work great in the barrel due to the rail sitting more in the waves face instead of on top of it.
PU boards have the best flex patterns and have a real lively feel to them, which we are always trying to mimic on EPS/Epoxy boards through different reinforcements like carbon strips or parabolic rails, which we will go into later.
Close up of the Super Brand Superflex construction.
But don’t go counting EPS out as an option.
Now more than ever, EPS has become a standard option for most brands board models for a number of good reasons.
One main noticeable reason for the surfer is that EPS is much lighter than your standard PU/PE boards. This makes for a great option for the aerialists out there.
They are easier to whip around both in the air and while on the wave.
Jack Freestone coming up for some air on his PU DX 1.
They also seem to have a more buoyant feel to them. In saying that, they tend to feel like they sit a little higher on the water than your standard PU boards.
This equates to getting up to planing speed faster, and can make a big difference when trying to fly by those flatter sections on clean days.
All these factors make small wave boards a blast when made with EPS/Epoxy.
The foam itself has a more consistent density throughout.
This means that when the shaper starts mowing into the foam to carve you out your gem, he does’t have to be so concerned with how much foam he is taking from the deck side.
With PU, the foam becomes less dense the deeper into it you carve. This means that shapers have to be aware and not try to take too much off the deck side, attempting to leave the deck as strong as possible.
Gavin Upson checking his handy-work in the 1-Da Shapes shaping bay.
It is a little harder to shape an EPS blank clean, and the raw materials are more expensive for the manufacturer, so one of the main down sides are the cost.
At a retail point EPS boards can be around $100 + more than your standard PU/PE. The cost can be well worth it though.
When looking at your standard shortboards, Epoxy resin (used on all EPS foam boards) is stronger in the sense that it flexes better than Polyester resin.
What this means is that it is less brittle and not as prone to cracking as Polyester.
Sometimes, if surfed too soon after it has been made, you might get some pressure dents.
The resin needs more time to fully cure, but if you are eager you can use this as an advantage on your shorties to know where that sweet spot is for you.
The aftermath of some Eye Symmetry resin tint laminations in California.
EPS for the Environmentally friendly
They are also much more environmentally friendly than standard PU/PE boards.
Some more than others, but for the most part, EPS foam can be recycled. The packaging from the last flat screen t.v. you bought can be brought to many collection sites, broken down and recycled into massive EPS foam blocks which then get cut or molded into your next blank.
The standard Epoxy resin takes less energy and resources to produce, and there are even brands out there using other bases as the resin source like pine tree sap instead of petrochemicals.
The combination of the two gives your board a much smaller carbon footprint than your standard PU/PE board.
Even in the surfboard manufacturing aspect, you don’t need chemicals like acetone, etc and they more or less emit 0 VOC’s (volatile organic compounds) that you can breathe in.
For the most part, they can be healthier for the manufacturers as long as they are wearing the proper protection and taking the proper steps.
With that said though, it is extremely important that they take these proper precautions.
You can become sensitized to some of the chemicals needed in the hardener for Epoxy resins, and if that happens it stays with you for life.
But which one’s for you?
There are many other factors that can be discussed, but for the purpose of this article, we are trying to look at which might be the best option for you to buy.
This will be determined by what you are essentially looking for out of your board. Both options have their merits that can’t really be compared.
Essentially, you have to look at what you want out of the board.
A rack full of the SUPERbrand Fling model in both EPS and PU/PE constructions.
For a great long lasting all-rounder, you would want to find a board that has the trusty feel and flex as your standard PU, but you also want the glass and resin job to be strong and sturdy as Epoxy.
Blending the two is always a great option. PU blanks can be glassed with Epoxy resin which gives you the feel of your standard board but with a stronger more flexible resin.
However, if you are looking for a more aesthetic look to your board, Polyester resin works better with colors and you can get a nice gloss coat for an amazing piece of resin art.
The Panda Surfboards Fried Till You Die in PU construction with a nice resin tint.
EPS does not handle Polyester resin well so for this outcome, you need to go the PU/PE route.
Or you if your really just need a high performance small wave ripper, stick with the EPS/Epoxy resin.
With the feeling of a little more buoyancy, and the super light, whippy feel to them, they make small wave surfing a blast.
The most important thing
The best result is for you as the surfer to be as stoked as possible.
Some people have the means to own a large quiver and others can only afford one board.
The pro’s definitely have the luxury to have the same models in both PU and EPS and can choose what they feel would work best for the certain conditions they are about to surf.
Adam Bennetts checking out a PU board with his quiver of DMS Surfboards in EPS Carbon Wrap construction behind him.
The average Joe usually has to be a little more picky with what they need out of a board. Hopefully this article helps lead you in the direction for the construction you need.
There is a lot more to surfboards constructions
that we will touch on later, and many brands that use specific techniques or may want a certain construction for a board depending on what it is intended to do.
Stay tuned for the next article that will go over some of these construction methods.
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