Tag: womens surf retreat

The Difference Between Epoxy and Polyurethane Surfboards

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We occasionally receive a message from an Amiga asking to be able to ride a “fiberglass board” on their Surf With Amigas Retreat as opposed to an epoxy board. The question always makes us grimace.

Unless the board is made from some unusual material like carbon fiber, ALL surfboards are wrapped in fiberglass. I think what most surfers are actually wanting is to avoid riding a “pop-out” board – as in the mass-produced SurfTech or NSP variety. When choosing a surfboard the actual factor to consider is whether the board is made with polyurethane (PU) or epoxy (EPS) foam.

Let’s Start with the Basics: How are Surfboards Made?

In case you have no idea how surfboards are constructed, we’ll start with the basics. Of course there are always experimental surfboards out there, but the vast majority of boards are made of a foam core wrapped in layers of fiberglass and laminated with resin. 

In the diagram here you see a foam core which can be “EPS” or “PU” (more on that in a bit), covered in layers of different weight fiberglass (in this case 4oz on top, 6oz on bottom), then laminated with resin. You can see the wooden stringer down the center represented as blue lines.

The surfboard starts as a “blank” which is a chunk of foam already in the general size and shape of a finished surfboard. The foam core, or blank, is formed in a large, cement mold roughly the shape of the surfboard. The mold is constructed in two halves, and the inside is lined with a special paper that keeps the foam from sticking to the mold. The two halves are clamped together and the mold is heated. When the liquid polyurethane chemicals are poured into the mold, the heat triggers a chemical reaction which begins forming a dense, white foam. Surfboard builders call this process, “blowing the blank.” After 25 minutes, the mold is opened and the foam core is taken out and allowed to finish hardening. Once the core is hard, it is cut in half vertically from the nose to the tail. A thin stringer is glued between the two halves, and the core is then clamped back together to dry. Stringers provide stiffness, strength, and the right amount of spring when the board is compressed through turns.

This process creates a blank that looks like a rough surfboard. It’s thicker, longer, and rougher than the finished product, but already more or less in the final shape. Surfboard shapers choose a blank closest in size to the board they want to make as the density is not uniform throughout. There is generally a slightly more dense outer layer and a softer inner layer. The shaper will then just use a planer to cut the blank down to the desired thickness, rail shape, tail shape and add bottom contour.

Here’s a Surfboard Shaping History Lesson:

From 1961-2005, 90% of American-made and 60% of surfboards made worldwide began as polyurethane foam (PU) blanks blown by Clark Foam in southern California. In 2005, citing difficulties from environmental regulatory agencies, he abruptly shut down his factory which sent shockwaves through the industry.

Vintage Gordon “Grubby” Clark in his foam factory, along with a lineup of three iconic Clark Foam “blanks”.

The sudden closing and destruction of the Clark Foam factory was seen as a big “f*ck you” to the industry and led to mild panic in some circles. Such was the power of this man and his near complete domination of the surfboard industry. See the photo on the right of the destroyed blank molds.

After the initial panic subsided, most shapers began to view the closure of Clark Foam as a good thing for surfboard material innovation. It ended a period of monopolistic control and created a new, free, open market for blank builders to come in with new technology and ideas. It also encouraged shapers to put more energy into experimentation with the more environmentally-friendly expanded polystyrene blanks. There are some benefits to the newer technology. For one, the density is uniform throughout the blank.

These new blanks are laminated with epoxy resins. Epoxy emits 50-75% fewer VOCs (volatile organic compounds) than polyester resin. Also epoxy is lighter than polyester. Under most circumstances, resin makes up a large part of a completed board’s overall weight. Not only is epoxy resin lighter than polyester, but less is needed per coat. This ends up meaning a much lighter surfboard – a big plus for most surfers. The biggest bonus however is the durability and strength of epoxy boards, not to mention the benefits to the environment.

TWO TYPES OF EPOXY FOAM

1. EXPANDED Polystyrene (EPS, beaded foam)

Expanded, or beaded, foam (EPS) is a relatively inexpensive and incredibly lightweight surfboard core. Manufacturers produce sheets of EPS by feeding tiny polystyrene spheres into a machine, then introducing steam coupled with a tiny amount of pentane gas to expand the beads and mold them to one another. The end result is an open cell foam, meaning that is very water absorbent. To combat this issue, shapers who use EPS foam usually add extra layers of fiberglass and epoxy resin to prevent any dings from penetrating deep enough to reach the foam. Epoxy resin is the only resin that can be used with EPS boards. The extra layers of fiberglass and resin make the boards stiffer and more solid feeling. It leads to a less flexible feel than a “traditional” board. A beginner surfer would not be able to tell the difference, but an advanced surfer who is compressing her board into high speed turns will definitely notice.

“Pop-out” boards are made using EPS foam, because the beads can be formed into specific molds. Often times these blanks are used without stringers relying on just the strength of the blank and the thicker layers of fiberglass in the glassing. The entire board is made in a mold or with vacuum bagging technology. This leads to the boards being less refined. They will be cheaper and more durable which makes them excellent for beginners who are not ready to invest in a more expensive surfboard. They are perfectly fine to learn on.

Originally, very few hand shapers use this type of EPS foam, because it is difficult to work with and nearly impossible to fine-tune with shaping tools (the beads retain their spherical shapes so well that any sanding causes whole chunks of foam to fall off, leaving the edges jagged). But recently better EPS with smaller cells has been created so that it now works for hand shaped boards as well. When Holly was a pro surfer getting boards from Rusty Surfboards, almost all of her boards were made of EPS foam and looking at the boards even up close, it would be very difficult for anyone to tell the difference of EPS vs PU in the finished board.

These days EPS foam technology has improved and high performance EPS blanks are available. Professional surfers and recreational surfers alike will choose EPS boards because of their environmentally friendly characteristics. They are also a lot lighter which makes them ideal for smaller waves or smaller surfers carrying bigger boards.

Characteristics of boards with Expanded Polystyrene (EPS) epoxy foam:

  • more water absorbent foam
  • lightweight
  • extra layers of fiberglass + epoxy resin for ding prevention
  • potentially more solid feel because of extra fiberglass + resin (less flexible for advanced surfers)
Holly Beck, rusty surfboard
Holly with an EPS and Epoxy board by Rusty Surfboards

2. EXTRUDED (XTR, closed cell)

Extruded foam (XTR) is made using expensive machinery and computers. The machines melt polystyrene crystals down, using additives and a blowing agent to essentially deflate and combine all of the ingredients together. The result is a fluid that expands as it cools, forming solid blocks of XTR foam. The foam is closed cell, so it blocks out moisture – a good thing in case you get a ding.

The process of making XTR foam is time-consuming and costly. The price of the foam itself, coupled with the fact that most XTR epoxy boards are hand-shaped, does unfortunately lead to a more expensive finished board – but one with several benefits. Not only is the foam core moisture-wicking and stronger than other types of foam, it is also extremely resistant to dings and compression-caused dents. XTR foam also has a good flex pattern, so it’s responsive on the water.

The problem with closed cell foam is two-fold. First, as mentioned above, it is expensive. You will almost always pay more for an XTR board than one made from EPS. Second, there have been reports of bubbles and delamination in the decks of some closed cell boards, caused by gas build-up between the foam, fiberglass and resin layers. However, some companies have made huge developments in XTR-constructed boards, finding ways to allow the gases to escape without compromising the integrity of the surfboard.

Holly has an XTR board that she’s been riding hard for over 15 years that is still in very good condition, something virtually impossible with other types of construction.

Characteristics of boards with Extruded Polystyrene (XTR) foam:

  • more expensive
  • moisture wicking foam core (doesn’t absorb water even when dinged)
  • stronger foam core
  • good flex for advanced surfers
  • extremely resistant to dings and pressure dents

Riding my XTR board in really fun waves about 15 years ago. It still looks good and works just as well today.

OTHER TECHNOLOGIES:

TL2 by SurfTech

SurfTech makes a Techlite core (fused cell foam, virtually waterproof) technology they call the TL2 design. The Techlite core is further improved upon with the addition of an Acrylite skin, which is glassed onto the board using epoxy resin. The Acrylite skin and the epoxy coating work with the core material to create an incredibly strong, responsive surfboard. The extra strength means that no stringer is needed, so the board is more flexible and springy in the water as well.

Hayden Shapes

Hayden Shapes is a quality surfboard manufacturer, also experimenting with different materials and designs. The Hypto Krypto is an awesome design for surfers wanting to go down in length but still keep paddle power since it has a wider nose for more planing but a narrower turn for high performance turns.

The construction combines a stringer-less, high-density custom shaped EPS core, laminated with biaxial fiberglass, epoxy resin and a parabolic carbon fiber frame. The carbon fiber frame within the laminate is the key to the performance vitality. Designed to maximize speed and drive while minimizing twist, FutureFlex essentially stores and releases energy as the surfer transitions through a turn. The FutureFlex construction creates a fast, dynamic and highly responsive surfboard that’s been design engineered for performance surfing ranging from the intermediate to advanced level.

This is Holly riding a surfboard made by a company called Aviso that no longer exists. It’s a hollow-core (no blank at all) carbon fiber board. The construction is similar to the SCore in that it is hollow, but made fully of carbon fiber so they are all black. (Tricky to keep the wax on when surfing one in the tropics as they get really hot). 

In summary – Epoxy vs Polyurethane

As described above, epoxy is lighter, stronger, and more environmentally friendly. An old EPS blank can be broken down and recycled into a new blank. The epoxy resin is less toxic to the board builder and the environment.

So what are the benefits of a lighter board? A lighter board is easier to carry, easier to paddle, and will often feel faster when riding them along the face of the wave. These all lead to more fun and froth, which is what it is all about. They are also very durable and maintain their integrity a lot longer than PU boards.

But, the epoxy boards can be stiffer and lighter which makes them tend to feel more “buoyant” and ride on top of the water, rather than in the wave. Since they are much more buoyant than PU boards, it is possible to ride shorter boards which can also enhance performance as the board fits better in the curve of the wave. Even pros ride EPS boards in smaller to medium-sized waves.

However, this buoyant feeling can make some people not like them. Also “pop-out” boards are made from this technology which can give the materials a bad name since they are associated with the image of cheaply produced junk.

In smaller, weaker surf, or for a beginner, the lightness is a really good thing. You will get the best weight to strength ratio with EPS/Epoxy construction; hand-built, composite, molded or otherwise. You’ll be able to lift a large board and carry it more easily to the water. For a surfer that is doing fast turns, the lightness of an EPS core combined with the strength of epoxy resin, will make for a more responsive, lively board.

It’s important to note that in bigger surf or choppy conditions, experienced surfers may actually prefer a slightly heavier board. Some older surfers who’ve gotten used to their PU boards will tell you that the feel and flex of a PU board is a feeling that will stick with you. Epoxy boards can have a “corky” feeling to them that can take some getting used to. Also, chop and windy conditions can make a lighter board feel like it’s bouncing more rather than plowing through the chop. Bigger waves are nice on heavier boards, especially if it’s also windy. In that case a PU blank with Polyester resin may be better.

A middle ground option is using a PU blank with Epoxy resin. Polyester resin will eat away (think: more nasty chemicals) EPS foam, but you can use epoxy resin with PU blanks so that’s a good compromise if you’re looking for the flex and weight of a PU blank with the environmental friendliness and durability of Epoxy.

Our advice: Get the board that you have the most fun on and makes you the happiest, because in the end, it doesn’t matter what you ride, as long as you are stoked.

Any guesses which of these are EPS and which are PU? It’s impossible to tell at a distance. 

How to Read a Surf Forecast – How Period Affects Wave Size

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waves are affected by Period

At Surf With Amigas Retreats we consistently hear the same remarks… “The surf report said 2-3ft but the waves are flat!” or “The report says 5-7ft tomorrow, is it going to be huge?”  The predicted surf height is arguably the least useful piece of information on the surf report. You should be paying more attention to the swell period!

If you look at a surf forecast you’ll generally see three bits of information:

  1. Swell size
  2. Swell period
  3. Swell direction

All are important. Most people just focus on the predicted swell size, but swell period actually has as much or even more to do with swell size in deciding how big the waves will actually be once they break at your surf spot.

Here’s an example of a surf forecast from Surfline showing three swells. On the left side, you can see the wave size forecast. This column tells you that Surfline predicts that the waves will be 3-4 feet at this specific beach.

How to Read a Surf Report

The next three columns (after the rating) show three different swells in the water. These are heights for the open ocean swells, not the size of the actual breaking waves. The first swell is 2.5ft at 16 seconds The second swell is 2.6ft at 12 seconds, and a third swell that at 6am is predicted to be 2.9ft at 7 seconds. The forecast predicts that the combination of these three swells will lead to waves in the 3-4ft range.

When I look at a surf forecast, I don’t even use that first column showing wave heights other than just as a guide that shows a trend – for example – are the waves predicted to be bigger today than yesterday? To me, the specific size predicted is relatively meaningless. You’ll know if you have ever looked at a surf forecast and then gone to your beach to check the surf, that the wave size predicted can be drastically off from reality.

The forecast given is usually for a general area or even a specific surf spot, but from the beach you’ll see that there may be 1′ waves breaking inside the cove of a point break, and 5′ waves breaking on the very outside even if the forecast says 3-4′. At a beach break, one end of the beach may be twice the size of the other side.

INTERESTED IN WATCHING SURF TUTORIALS? CLICK HERE.

SO HOW IS THIS INFORMATION GENERATED?

Swell forecasts use buoy readings which are then plugged into a computer model to predict readings in the future, usually at maximum up to 10 or 12 days out. A buoy is out there on the ocean measuring the rate and the distance that it is moved up and down by swells. It measures the height of the swell bump (crest) and the distance in time (wavelength) between crests. Since surf forecasts are predictions, they are most accurate within only a couple of days. Forecasts more than 5 days out should be taken with a grain of salt, as a lot can happen to change swells in that time, resulting in smaller or larger surf than first predicted.

HOW ARE WAVES CREATED?

Waves are formed by wind blowing over the surface of the ocean. The further away the storm begins makes a difference. A weak storm far away may dissipate before it creates a very large swell. But if there is a big strong storm originating on the opposite side of the globe, that maintains its strength and high wind speed at it travels, it will transfer a large amount of wind energy into the ocean which creates a long period swell.

If you’re looking at a surf forecast, by “long period” swell we’re usually talking 14” and above. However, where you live plays a factor in what is considered “long period”. In southern California, swells of 16″ or 17″ typically count as “long”. On the east coast or in the caribbean, an 11″ or 12″ period counts as “long” due to the fact that the average period tends to be smaller.

These long period swells contain energy created by wind that gets pushed down into the ocean, which means the swells typically move further below the surface and are more affected by bottom contour but less by winds and swells from other storms. This is why long period swells can maintain their energy over a further distance.

How DO waves travel?

Swells travel as a group of waves or “wave train”. As the swell moves forward, the wave in the front of the wave train will slow down and drop back to the rear of the group while the other waves move forward by one position. Then the next wave in front moves back and another takes its place — much like a rotating conveyor belt that is also moving forward. It’s a process somewhat similar to the “drafting” technique used by bicycle racers, and it enables wave trains to conserve their energy as they travel great distances across the oceans, working together to sustain energy.

SO, WHAT ELSE AFFECTS THE SIZE OF WAVES?

Bottom contour plays a big role in affecting the size of the waves from any swell, and wave height forecasts don’t always take that into account. For that reason, it’s much more useful to understand how to read the swell prediction from the buoy numbers, then after developing familiarity with your local beach you can better predict the actual size of the waves you will encounter that day from looking at the numbers. That’s what we’ll attempt to explain below. Bear with me, there’s some science and math involved!

If you’re a math geek or like numbers keep reading. Otherwise, skip down to “shoaling”…

You can calculate the speed of the waves with this formula: The speed of a swell or “wave train” is 1.5 x period. So looking at our example forecast above the 13” swell will have a speed of 1.5 x 13 or about 19.5 knots and the 22” swell will be 1.5 x 22 = 33 knots. If you want to convert that to mph (because who understand knots anyways?) the conversion is 1 knot = 1.2 mph. A 13” swell moves at 23.4 mph and a 22” swell moves at 39.6 mph. So a 22” period swell is moving at double the speed of a 13” swell. Individual waves move even faster. This is the speed of the wave train. If you want to calculate the speed of an individual wave, it is swell period x 3. So an individual wave in a 13” swell is going to be traveling at 13 x 3 = 39 knots or 46.8 mph vs a 22” period wave traveling at 22 x 3 = 66 x 1.2 = 79.2 mph.

Again, think of the wave train like a rotating conveyor belt that is also moving forward. This is the speed the wave travels through open water, not the speed that the wave will be traveling when you’re sitting in the water waiting to catch it. As the wave train moves into shallower water or encounters a rock shelf, headland, or beach the speed will slow down.

DeptH:

Waves begin to feel the ocean floor at a depth of 1/2 the wave length. To figure it out you take the number of seconds between swells, square it, then multiply by 2.56. The result will equal the depth the waves begin to feel the ocean floor.

So a 13” swell = 13 x 13 = 169 x 2.56 = 432’

But a 22” swell = 22 x 22 = 484 x 2.56 = 1,239’ deep

So longer period swells are more affected by bottom contour and that’s why they are called ground swells (typically over 13” long). We call shorter period swells wind swells because they are always generated by local winds (even though all waves are actually generated by wind), and usually can’t travel more than a few hundred miles before they decay.

Shoaling:

When waves approach shallower water their lower reaches begin to drag across the ocean floor and that friction slows them down. The wave energy below the surface of the ocean is pushed upward causing the waves to increase in height. The longer the period, the more energy under the surface, which is why longer period waves grow bigger than short period waves.

A 3’ wave with a 10″ period may only grow to be a 4’ breaking wave but a 3’ wave with 20 seconds may grow to be a 15’ breaking wave – more than 5 times the deep water height depending on the contours of the ocean floor.

As the waves pass into shallower water they become steeper and unstable as more and more energy is pushed upwards, finally to a point where they break at typically a depth of 1.3 times the wave height. So a 6’ wave will break in about 8’ of water.

A gradually sloping bottom will create a crumbly slow-breaking wave while a wave traveling over a steep ocean floor or hitting a reef result in faster hollower breaking waves. As the waves move into shallower water the speed and wavelength decrease (the waves get slower and closer together). So it isn’t that looking at a swell that is 20” means that the waves will come 20” apart. It’s a more complicated formula affected by so many factors.

Wrapping:

An aerial picture of one of the greatest point breaks – California’s Rincon – aptly called “queen of the coast”, demonstrating how a swell will wrap around a headland.

 

Here you see waves approaching from the right moving in towards shore – the grey area on the left. The black dot is a reef or sandbar. As the waves bend around it they cross up. This is the perfect situation for a peaky beach break and what makes the Northern Nicaragua surf spot “the Boom” work. In that case theres an outer reef that makes the waves cross up.

So from everything we’ve discussed above, you should have an idea of why and how this wrapping happens. The wave train approaches the coast, as it starts to “feel” the bottom it slows down and starts to break. The swell energy that has not yet felt the bottom continues traveling forward but the friction causes it to bend a bit and the lines wrap inwards, creating a very long “perfect” wave for surfers to enjoy.

This wrapping effect is most visible on a point break, but it can happen whenever an obstacle is encountered,whether it is a sandbar, reef, river mouth, bay, or even man made object such as a pier or jetty. If you are looking for waves with better shape, look for a coastline with some feature that will help the swell to wrap. If you have a long straight beach break without anything to break it up you will most likely have long closed-out waves.

In Summary

Swell forecasts tell you a lot more than just what size waves they are predicting for any particular beach, and that other information – including swell height and period can actually be more useful in helping you to predict the size of the waves breaking that day at your local break.

The best way to start understanding surf forecasts is to look at the forecast, then go to your beach to check the wave size. Notice the difference in predicted size vs. the size of the waves you actually see breaking. Then the next day, do the same thing. And the day after that…. Over time you’ll start to see a pattern and figure out which combination of numbers creates the ideal situation for the type of waves YOU like to ride. Then you’ll know which days to call in sick and score!

Special thanks to Surfline.com for assistance with the mathematical formulas quoted above.

FOR MORE SURF TUTORIALS CLICK HERE.

The 3 Best Face Sunscreens for Surfing and Other Strategies to Stay Protected From the Sun

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Wondering how best to protect your skin while surfing?

Here are our top three picks for sunscreens that stay on your face for surfing, as well as other strategies to minimize sunscreen use but still stay protected.

1. Shiseido 

Shiseido offers a variety of water resistant sun care products that work greta in the surf! Our favorites are the SPF 50 Sunscreen Stick and the Wetforce Ultimate Sun Protection Lotion. The Wetforce sunscreen is mineral based and free of chemicals. Both of these broad spectrum, water resistant products are have a matte finish that leaves your skin feeling smooth and dry.

Other strategies to stay protected from the sun:

In addition to staying lathered up with sunscreen on your face, neck, and hands, we highly recommend investing in other surf gear to keep you safe from the rays. Cover up! Hats, long sleeve rash guards, and leggings are a must if you plan to surf for years to come and spend many hours in the sun. These are some of our favorite small brands that make awesome surf gear for all women (and some men too)!

Fave hats: Kaiola Co.

Fave rashguards: The Seea

Fave leggings: Salt Gypsy

Highlights from Jan 15-21 in North Nicaragua

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This week not only did we surf our brains out but we also got to help out our local non-profit, waves of hope, by painting the local high school! Don’t worry, we managed to fit in all the other awesome activities of our Women’s surf and yoga retreat program including yoga, sliding down a volcano, a fun girls night out and sunset cocktails at a neighboring resort!