UNDERSTANDING INFLATABLE BOARD CONSTRUCTION

A paddleboard can be an investment in a long lasting product or it can be a short lived purchase due to poor quality.

Inflatable paddleboards come in a vast range of qualities and prices, so it’s important to understand how they differ in regard to materials and construction methods. We believe that the best purchase decision is an informed decision. 

INFLATABLE CORE LAYUPS

All inflatable paddle boards start with an inner bladder made of drop stitch fabric. Drop stitch, in a general sense, consists of two parallel sheets of fabric which are connected by in our case thousands of 6-inch long threads, much like a bridges structure. More threads equal more structure.  This is easily identifiable by counting the "dimples" on the bottom of a board.  If you are comparing qualities this is an easy place to start. Take something like a ring or a cookie cutter, drop it on the board and start counting. When the edges of the top and bottom fabric sheets are joined by air-tight material and the bladder is inflated, the threads confine the movement of the top and bottom sheets so that it maintains a board shape rather than curving outward like other inflatable objects. Increased number of threads ensure your board will retain its shape, higher internal pressures which create rigidity, and support the curves that help contribute to its overall performance. 

The inflatable core of a paddle board is made with a single layer (with several variants), fusion, or dual layer construction, while the rails are made with single or double rail bands, and in some cases and additional reinforcing strips for rigidity.  Here’s a basic description and additional comments regarding each construction:

SINGLE LAYER (DROP STITCH FABRIC)

In a single layer construction, the drop stitch core is made from single ply sheets of fabric at the top and bottom, which are sealed with a layer of flexible PVC plastic coating.

Single layer drop stitch is what you’ll find in most boards below $600, big box store brands, high volume boards that are found on many shopping sites as well as companies trying to gain entry into the paddleboard market on price alone.  The material is not very rigid inherently, boards made with single layer construction have a bouncier feel and are more susceptible to puncture and leakage. Some companies are using single layer construction but give their materials made-up names to imply they are a fusion style material. It is another area where a buyer has little information to go on other than what is claimed by the manufacturer, and since there is no universally accepted naming convention or "SUP police", many companies will take advantage of this.

It is also very common for companies using single layer materials to compensate with an over-the-top rail layer setup (implying 3 or 4 "layers") that offers no actual benefit because, if the core is weak, you cannot add strength to it after the fact.

ANAHOLA BOARD CO.  does NOT nor will ever use single layer construction in the manufacturing of any SUP boards.

FUSION (DROP STITCH FABRIC + WOVEN FABRIC + PVC COATING)

Fusion/ MSL (Monocoque Structural Laminate) construction is a sweet spot for balance of weight, rigidity, and cost effectiveness.  The top and bottom sheets of the drop stitch have two layers of fabric that are permanently bonded to each other, and a layer of PVC coating on the outside of this double ply fabric. The resulting board is significantly more rigid and puncture resistant than a single layer board. Expect this construction in boards from $700-$900 and up. The added rigidity of the material allows boards to be made in 5” thickness without having to resort to excessive board thickness for the sake of rigidity.  It also provides a smoother printing surface lending itself to higher resolution graphics.

As mentioned, a trend of great concern is manufacturers implying the use of fusion materials on boards that are actually made of single layer fabric.  Some "creative layer-counting" takes place for the sake of advertising, so read construction claims critically.  A common practice is to count adhesives or coatings as "layers", which muddies the waters quite a bit with regard to the actual composition of the materials used.  The use of crossed weave single layer has become common in single layer boards who make the claim the material is fusion or dual layer but this is not the same thing as authentic fusion or dual layer construction.

Another interesting take is calling fusion boards "dual layer fusion".  By definition all true fusion boards use a double layer drop stitch so any implied advantage to "dual layer fusion" is null.  A large part of a boards cost is tied up in transportation, freight and shipping.  Shipping rates are always mileage and weight indexed so companies are highly motivated to reduce board weight by creatively marketing layers in a effort to increase profit margins.  In an ever competitive marketplace where profit sadly overshadows quality, there are more and more manufacturers opting for this layup.  

ANAHOLA BOARD CO. has fully evaluated this layup and does not currently use fusion material and construction in our boards as it does not yet meet our rigorous quality and testing standards that we are known for.  

DUAL LAYER (DROP STITCH + PVC COATING #1 + ADHESIVE LAYER + PVC COATING #2 + WOVEN FABRIC +ADHESIVE LAYER + PVC COATING #3)

Dual layer construction is the “cost is no object, gold standard” inflatable layup, as it involves additional costly materials and labor to build the board.  It starts with an inner bladder made with single layer construction, but then the entire bladder is laminated with an additional sheet of PVC coated fabric.  Boards made this way are superior in durability, rigidity, and rocker profile control and are more difficult to puncture and less prone to leakage since they have additional coating layers between the fabric sheets. The additional layer adds between 1.5 - 2 kg to the overall board weight and a significant increase in material cost. This construction is used to produce a board that feels extremely well balanced and grounded underfoot.

Technically, fusion material also has two fabric layers, but it should be noted that there is a distinct difference between fused material boards (two layers of fabric fused at the raw material stage, with a single coating applied to the outside surfaces) and actual dual layer construction boards, in which a second distinct layer of PVC coated fabric is laminated to the board.  As mentioned above, dual layer construction generally adds weight to a board, so comparing board weights can help you discern whether a board is truly made with two distinct layers of PVC coated fabric or if a brand is advertising with creative wording to imply additional layers that don't exist or are non functional for rigidity or durability. 

While some manufacturers may be using similar materials, different methods of constructing the board can make the most impact on the longevity and performance of a board.

 

ANAHOLA BOARD CO. uses true dual layer construction in all of our boards, assembled using proprietary construction and assembly methods by certified craftsmen. It provides the best available materials and workmanship available across the globe.  This is the gold standard layup with no sacrifices in materials or quality.

RAIL LAYUPS

The rail, or edge, of an inflatable SUP is made by joining the top and bottom sheets of the board with strips of reinforced PVC coated materials in an airtight manner.  The physical properties of the materials used to form the rails can have a significant effect on the rigidity, longevity and performance of the board. While most people focus on other areas of a boards construction, rail construction is bar none the most critical component of the entire assembly.  

SINGLE RAIL BAND WITH TAPED SEAMS

A single band of PVC coated fabric along the sides of the board is the cheapest way to close off the containment layer, but the most vulnerable to puncture and leakage. It is most often used in low quality boards where every optional cost must be eliminated. You will find this method used in boards in the $300 - $600 range.  Boards made with single layer rails can often be identified from the 1 inch width strips of PVC used to tape or cover the rail seams. Generally these are only held in place by vinyl adhesive.  To the layman's eye , if a board rolls up like a sleeping bag, it is a very clear indicator you have a single rail band (read: lowest quality) rail layup. Due to the abuse the rails take, many boards made in this fashion fail to see their 3rd birthday unless handled with kid gloves. 

 

DUAL RAIL BANDS

In dual rail construction, an inner band seals off the containment layer and a wider second band is bonded over the top of it. This is the most common rail configuration, but details on how it is specifically implemented can make a significant difference in board strength.  Boards with a larger gap between the edges of the drop stitch layers (less overlap with the inner rail band) are easier to build but have less structural integrity than boards where the drop stitch fabric layers fold farther over the sides leaving a narrower gap to close with the rail band.  Boards with this rail layup don't roll up easily and are generally folded.        

DUAL RAIL BANDS + STIFFENING LAYER

Adding a strip of low stretch (high tensile strength) material to the rail can improve rigidity while providing an additional layer of puncture resistance. It is also an area where false marketing claims abound. Carbon fabric serves no mechanical function as a rail stiffening material. Carbon fiber must be impregnated in an epoxy resin to realize its potential strength, in which case it becomes extremely rigid and impossible to fold. The addition of carbon fabric tape to rails is actually a surfboard throwback to tune a hardboard shape and carbon tape is pliable and useful for that specific application. Carbon fiber is great for rigid and lightweight paddles, but provides no significant structural or rigidity benefit to the rail of an inflatable SUP board. Stiffening layers are great marketing hooks used by brands to "reel em in" but sadly serve no structural purpose.   

DUAL RAIL BAND HEAT WELDED + ADHESIVE (2+1) RAIL

Heat sealed or welded rails are quickly becoming the gold standard for all of the top companies in the industry and are a key element separating the top manufacturers from the rest. A heat welded rail is however somewhat of a misnomer as the weld is usually a partial connection over the inner fold while the core construction of rail is completed with adhesive. A variant of the techniques welds the underside of the inner seam and uses adhesive for the top part of the inner seam and the entire outer seam.  Inflatable boards require adjustment during the setting process so a completely welded rail would not allow this to occur. There are some minor variations to the welding technique through the mechanical and chemisorption strength properties of a purpose specific adhesive and can be as strong as the base material itself providing incredible durability, reliability and longevity.

Construction processes differ between manufacturers / factories to a degree so the assumption that everyone uses the exact same adhesives, techniques and processes is incorrect, though some standardization and techniques are commonplace.  We source specialized adhesives to ensure the bond is complete and long lasting.  The construction of a performance stand up inflatable paddle board is a synergy of materials, outline shape and manufacturing processes. Getting it right is expensive and time consuming since the end product is only as strong as its weakest link. We rely on trained craftspeople to execute these processes which are then verified via high pressure internal and external visual testing in a water tank. This extra testing step is critical to ensuring our boards are made correctly to our specification.  Our boards are all manufactured using a proprietary dual rail band + heat sealed methodology which also incorporates an additional internal dual rolled rail. This process is slower and more labor intensive to create and requires years of training and close supervision to execute properly, but what it ensures is superb performance of the most critical component of the board and gives a rail that is second to none.

FIN BOXES

 

CLIP FIN SYSTEMS

Clip fins were some of the first out when the industry was just getting its legs.   They are secured by a plastic clip that hold the fin to the fin box.  Where clip fins lack is in the ability to customize and their inherent desire to break off and the clips to get lost at the most inopportune times.  Some of our early models had clip fins but we quickly moved away from them as far superior systems became mainstream. 

US FIN BOXES

At a minimum, a quality board designed for long lasting performance should have a center fin box that fits different types of fin you’ll use and lets you move the selected fin forward and back to affect the board’s propensity to turn easily or track straight.   The most versatile center fin option is a US Fin Box, which is a standard in the surf industry as so many fins are available to use with this fin box.  This will give you the option of, for example, using a shorter center fin in shallow river water, a flex fin for rocks and abuse,  or a longer race fin when you want stability and to go fast where water depth is not an issue. There are literally thousands of aftermarket fins available for every possible paddling scenario. Recently, rear battery powered thrusters that attach to US Fin boxes have been brought to market adding a new exciting dimension to paddleboarding. Other additions like underwater lighting kits are becoming popular with the night paddle crew and new products that incorporate this system are being launched daily.

A FINAL NOTE ON BOARD CONSTRUCTION

Most of the construction details described here are completely invisible to an average paddleboard buyer. As a result, some companies, particularly on the lower cost end of the market, are hyping their board constructions using misleading language to imply additional material layers that do not really exist on their boards - or - have no actual effect on design parameters such as rigidity / durability they claim them to.  Often review websites and press releases will just rely on this and repeat the companies claim (we give them the benefit of the doubt as they are not required to know the ins and outs of SUP construction). Sadly, just because something is repeated over and over it does not become truth - though the perception of it being truth or fact can gain momentum. Just because its in a big box store does not mean it is high quality. What it means is there is enough profit built in at your expense that they can accept horrendous returns and still turn a profit.  If a corner can be cut often it will be to the detriment of the buyer, the industry and the environment. Cheap adhesive, core materials and lower density EVA are common place at the low to mid end of the market and sadly even among some of the more well known brands.

For this reason, we advise caution in believing unsubstantiated marketing claims. To protect yourself, we recommend getting to know the brand you are buying so you can feel more confident in knowing you are getting the construction that is advertised.  Look for companies willing to speak truthfully and explain their specific construction and technologies.  Companies that cannot or will not explain these things are generally companies who purchase off the shelf designs from volume manufacturers and simply change the aesthetics, slap on a logo, and fit the board with cosmetic accessories in an effort to compete in a competitive paddleboard market.   Look for companies that aim to educate not promote. Feel free to reach out, we are always happy to have a transparent discussion about any further questions that you may have regarding your purchase weather it be one of ours or another brand.  Happy Shopping!