epoxy vs fiberglass board

What are surfboards made of?

Picking the right type and size are one of the most important factors when choosing a surfboard.

Surfboard shapes and materials are designed for their special purpose, not by a chance. In this post, we are going to examine the main surfboard materials used today, and what are the characteristics of each type.

Fiberglass / Epoxy / Foam

  • Fiberglass surfboard is made of polyurethane foam core with a wooden stringer in the middle, coated with fiberglass cloth & fiberglass resin.
  • Epoxy surfboard is made out of expanded polystyrene foam core, fiberglass cloth, and epoxy resin. Only a few epoxy boards have a wooden stringer.
  • Foam surfboard is made out of foam, and coated with fiberglass or a synthetic wrap. Foam boards do not have a hardened cloth in between the board and the outer layer.

different surfboards

 

What are surfboards made of?

Two main surfboard materials are fiberglass and epoxy. Beginner’s and some fun boards are made of foam. Since the very beginning of surf history in the 12th Century Polynesia, surfboards were made out of solid hardwood (Balsa wood).

What is a surfboard made of?

To be more exact, both fiberglass and epoxy boards use a foam blank (PU or EPS), but a different resin that covers the board. Fiberglass surfboards also have a wooden stringer in the middle for added durability since the boards have more (needed) flex to them.

  • Fiberglass (PU – Polyurethane foam core), fiberglass cloth, wooden stringer, fiberglass resin.
  • Epoxy (EPS – Expanded Polystyrene foam core), fiberglass cloth, epoxy resin.

How are surfboards made?

The making of a surfboard starts by ordering a specific surfboard foam blank. The foam density in those blanks is already measured for a specific surfboard type and future material use.

  • PU Fiberglass surfboard blank density – 36kg/m3
    TDI – Tolulene-di-isocynate & MDI – methylene-di-isocynate
  • EPS – Epoxy surfboard blank density – 16-28kg/m3
  • XPS – Extruded Polystyrene – 32-48kg/m3

The process of making a EPS / PU surfboard from a surfboard blank.

  1. A specific blank is ordered from a manufacturer.
    Fiberglass blanks come with a stringer in the middle, epoxy blanks usually don’t. There are blanks for each surfboard type: fish, longboard, gun, midlength, etc.
  2. A surfboard blank gets shaped to a specific dimension & curvature.
  3. Fin box installation.
  4. Hand-written surfboard size gets signed on the bottom of the blank.
    Sometimes automated on the outer shell.
  5. Board gets covered with fiberglass cloth (on EPS and PU boards only).
  6. Blank & cloth get laminated by fiberglass or epoxy resin.
  7. Curing process.
  8. Sanding & finishing.

*DYI surfboard blanks come with pre-cut rough dimensions of a specific surfboard type.

Why is surfboard size marked in liters?

  • 7’2″ x 21 3/4″ x 2″ = Imperial
  • 45L = Metric

Surfboard volume determines whether the board is right for your weight and riding preferences.

Surfboards are designed for a specific rider, that’s the reason why there are usually five or more sizes available in a series. Volume is marked in liters (@45L). The surfboard volume determines how much space does a surfboard occupies. To get the estimated volume – you’ll need to convert feet & inches to centimeters (imperial to metric), and multiply the sum by x0.54 (smaller boards) x0.56 (average boards) x0.58 by.

Check out more from our slide-bar surfboard volume calculator.

surfers in the water
Surfboard volume determines the float

How to make a surfboard?

The easiest and best way to make your very own surfboard is to buy a pre-equipped kit. This allows you to cut the surfboard in the right size and preferred outline, plus it’s got everything you need to finish the board by yourself.

DYI surfboard kits usually consist of:

  • Raw foam surfboard
  • Fin boxes (FCS, FCS II, Futures)
  • Measuring tools
  • Fiberglass cloth
  • Surfboard mold mix – either epoxy or fiberglass

 

What tools do you need to shape a surfboard blank?

To shape a surfboard foam blank you’ll basically only need a carpenter’s saw, hand plane, and sandpaper.

 

What is the best surfboard material?

By today, surfboard manufacturers and shapers have worked out the most optimal material use for each specific surfboard type.

  • Fiberglass surfboards are the best choice for messy and above-average conditions (clean and glassy). They do ding easier than their epoxy counterparts but benefit from having a better flex and ‘feel’ to the board on not-so-glassy conditions. In general, it takes longer to make a fiberglass surfboard. Although TDI fiberglass had a bad rap by not being as environmentally friendly as epoxy surfboards, a newer material of MDI has fixed that issue. Fiberglass board replaced balsa wood and used to be the one and only surfboard material for decades before foam and epoxy boards came along.
  • Epoxy surfboards are a booming market next to fiberglass surfboards. These boards are bright-white and known for their stiffness, which translates to responsiveness when riding. Epoxy board is fast and sharp, great for above-average conditions. Although they do not usually have a wooden stringer in the middle for added strength, epoxy boards are known to be more durable.

 

Fiberglass surfboard

PU = Fiberglass

  • Fiberglass replaced balsa wood in the 1960s.
  • Less density than an EPS surfboard.
  • One of the main surfboard materials used for nearly a century by now (First in 1946).
  • There’s more ‘give’ to a fiberglass board, making it a great choice for wide-open beach breaks and demanding conditions.
  • PU surfboards have a wooden stringer in the middle which allows the board to flex, add durability and also prevent it from twisting.
    CONS
  • On the downside, the fiberglass surfboard foam turns yellow once the water has entered the core, especially when it won’t get aired out. This unfortunately weakens the whole surfboard.
  • Dings & dents reduce the volume of a fiberglass surfboard.
surfboard epoxy and fiberglass
A lovely border terrier (left), an epoxy surfboard with a stringer (middle), and a PU board (right)

Epoxy surfboard

EPS = Epoxy

  • Foam blank is air-tight with a closed-cell structure.
    A new trend of fused cell type of polystyrene is being used that reduces water absorption even more. 
  • EPS core is more durable.
  • Feels light.
  • Better float.
  • Very responsive and sharp feel.
    CONS
  • Not as great on messy conditions.
  • Epoxy resin is about 35% stronger than fiberglass resin.
  • More expensive to repair.

 

The SUM


What is EPS epoxy surfboard?

Epoxy surfboard has an Expanded Polystyrene foam core, fiberglass cloth, and epoxy resin. Wooden stringer in the blank comes as an option.

Which surfboard is easier to fix – fiberglass or epoxy?

Fiberglass surfboards are easier to fix on your own by using a UV-curing repair kit. Epoxy surfboard resin doesn’t ding as easily, but they need a more advanced pair of hands when it comes to DIY fixes.

Check out how professionals do it:

 

Is epoxy longboard any good?

Epoxy longboards become more common due to their durability in and out of the surf. Although a classic fiberglass longboard has better flex to its length, an epoxy board is faster down the line.

Epoxy vs Fiberglass Surfboard

PU vs epoxy surfboards is the main concern among beginners and expert surfers alike. Both materials have their pros and cons, which means we can’t really rule one out to highlight the other. It all comes down to personal preferences which board fits you best. There isn’t a better board in windy conditions than fiberglass, and an epoxy board shines in glassy conditions where you need a sharp and fast deck.

When it comes to longboards, fiberglass is the main material to choose from. The longer the board, the sturdier it has to be and when talking in surf terms, an epoxy surfboard

What are the parts of a surfboard?

  • Surfboard – Made out of foam (with or without a wooden stringer), fiberglass cloth, resin.
  • Fin box – Made of plastic.
  • Leah plug – Platic box & metal rod.
  • Traction pad – Eva foam.
  • Leash – Urethane cord.
  • Velcro strap – To hold the leash.

kona surfboards

Why are surfboards so expensive?

Surfboards might seem simple and basic, but there’s quite a bit of time and effort put into the making. Although the parts themselves don’t cost a fortune (maybe 30% of the whole board), it is the process of making one by an automated CNC machine, or by hand. Every angle of the board is precisely thought out to fit a specific surfer and wave, and it takes a special tool or skill to cut the board into it.

Related – What is the cost of surfing?

 

Are surfboards made of wood?

Nowadays there’s only a handful of manufacturers who still make surfboards out of wood. Although wooden surfboards are many times heavier than EPS or PU boards, there’s still a market for such boards. A modern-day wooden surfboard is made out of multiple planks glued together while back in the day, wooden surfboards were made out of wood.

How much does a surfboard weigh?

Surfboards manufacturers are working hard to offer as light board as possible while keeping its strength and durability. Surfboard weight and float don’t have any correlation since the foam (or even wood) density varies quite a bit.

  • 10′ Longboards weigh around 16lbs
  • Midlength / mal boards way around 10-12lbs
  • 6′ Shortboards weigh around 6-7lbs

Surfboard damage types

Fiberglass surfboards are an ideal choice for those massive waves, but if you squeeze the board by your hand hard enough – it will dent. That being said, fiberglass surfboards need extra care in and out of the surf. Damaging a surfboard is inevitable, and

  • Dings – A damage that reaches up to the foam core.
  • Compression dents – Appear with hitting the board with knees or elbows when surfing.
  • Cut – Either from a shallow coral reef or by another surfboard fin.
  • Snapped surfboard – This can happen when the board gets smashed inside the wave, after a heavy drop, or simply by riding to the shore and hitting the bottom.

All of the damage types can be repaired in case the foam core hasn’t been fully submerged.

broken surfboard
A broken surfboard

Resource – sanded.com.au/pages/core-basics

 

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About the author

Ermo Joeleht

I created Nulltuul to share my experience, knowledge, and analysis with other surf enthusiasts out there. If I'm not surfing on my travels, I like to photograph waves, surfers, and the surf lifestyle in general.

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