The wooden stringer has been the veritable backbone of the surfboard for over half a century. In recent years there has been new takes on the stringer, such as parabolic rails, yet the concept is the same: a stiff strip (or strips) of material to support the surfboard's core.

Varial Foam take a new approach to board building. Rather than rely on a stringer as a crutch for strength they "start with a good core first" as the basis for strength and performance. The stringer, therefore, becomes unnecessary.

Varial Foam were started by Parker Borneman and Edison Conner, their goal being to build the world's most high performance surfboards. Fifty year old technology has no place in their boards, even when those boards are being ridden in the biggest waves on the planet, as evidenced by Shane Dorian riding a stringerless 9'8" during recent sessions at Jaws and also at last Friday's Eddie Aikau where he placed third.

Swellnet recently spoke to Parker Borneman from Varial Foam.

Swellnet: You say that all blanks should be stringerless, does that include 10 foot guns for 50 foot waves?
Varial Foam: When we developed Varial Foam, we wanted to eliminate variables in a foam core which negatively effect the performance of a surfboard: glue lines, varied densities with soft centres, pour lines and especially stringers. With this in focus we knew we needed to create a stronger more rigid foam which didn’t need a stringer reinforcement. It’s difficult to make something bend and not break while also being light. After achieving this, the easy part was adding more fibreglass for strength on boards which needed to hold up exceptionally well, like Shane’s 9’6” Jaws gun. 

So you were confident that serious big wave guns wouldn’t require stringers?
We were very confident that we wouldn’t need a stringer for serious big wave guns. The seven-times rigidity of Varial Foam over standard surfboard foam eliminates buckling. By doing that you’re able to use 100% of the fibreglass strength, which makes any Varial Foam board 30% stronger than a traditional foam board of the same glassing. So a Varial Foam gun will be stronger than a normal gun with the same amount of glass. It will be lighter too, so you can add even more glass and strength if desired.

Why not put a stringer in? The board, after all, is already a bit lighter by using Varial foam. Does having a stringer affect how Varial blanks perform?
There are a few reasons to not put a stinger in a Varial Foam blank. It would definitely make the board too stiff in length-wise flex. It would also vary the flex from board-to-board, as wood is naturally inconsistent. Both the addition of the stringer and glue would add unnecessary weight. The flex of the board would also break down with each use as the natural wood fibres deteriorate with each bend. Having one solid, uniform core yields great flex and strong pushback without ever losing its pop.

Stringers help compensate for the softness of foam in standard blanks, but strength should really be derived from a stronger, higher-performance core material. That’s why you never see wood stringers reinforcing advanced core materials in aerospace parts.  

Flex is being engineered into blanks these days - think about DHD’s new EpoxiCore or X-Core - how does a uniform stringerless blank perform flex-wise?
The performance of a board largely comes from the modulus - that is, the rigidity - of the core. With a stringerless, high modulus blank like Varial Foam, you get a lot of strength without sacrificing flex. With standard glassing our foam has inherent longitudinal and torsional flex that is very close to standard PU blanks with a stringer. The inherent flex properties of our foam make fast and lively small wave boards, and adds more control and responsiveness to big wave guns. Luckily we don’t have to start with a light weight EPS core and add things to it to make it perform better. You can also glass Varial Foam with polyester resin, which gives shapers a lot of options for finishing the board. It is all about starting with a good core first as the basis for performance.  

Will the smell of Varial foam be improved? A shaper I know had an olfactory nightmare after shaping a Varial blank!
Our foam does have a very unique smell which is due to our blowing agent. We use highly engineered materials in our entire process to create our foam, and the alcohol-based blowing agent isn’t something we can replace if we want to continue to make consistent, uniform blanks. We recommend using proper respirators which can filter organic vapors, but our foam is non-hazardous to work with.

Many shapers like the smell of it, so I guess it’s a personal preference.