Border Materials
The type of materials and methods used in constructing net borders is extremely important to the strength and durability of nets. The actual reinforcement we use varies with the material and border type. In most Mesh and Open Net borders we attach a stiff vinyl material to the net, where the mesh is folded over the reinforcement and stitched with several rows. This border is then covered with a finish vinyl coated fabric, and stitched with multiple rows of stitching.
Grommet borders, the most common type on mesh nets, will have 5 or more rows of stitching on the finish border cover and more rows under. Multiple rows of stitching are important as it insures a solid bond between the netting and the border to spread the loads from the attachments as wide as possible. With larger nets made of the stronger netting materials, we use wider borders and add additional layers of reinforcement to support the greater loads that will be encountered on these nets.
Other common borders include pipe sleeves, where a rod or tube is inserted through a sleeve and laced through cutouts in that sleeve, cable sleeves, and boltrope, where a rope is sewn into the border so that it can be inserted in to a track or beam slot on the boat. These borders are composed of 2 plys of material, the first usually of the net mesh and the second, usually a finish vinyl fabric. In this method the initial stitching is covered by the finish vinyl. It is important that boltrops be made of 2 plys of material to protect from chafing and add strength.
Unsupported spans require a different approach. Here the entire side of a net is supported only at the corners. The border in this case is under tension along its length. In these borders we use high strength, low stretch webbing and build the side to form a catenary curve so that the border can provide support to the netting. As in the other borders, this webbing and its attachment stitching is covered with a vinyl fabric for protection form the elements.
It should be noted that the strongest border is found on the webbing nets which actually have no border. With the diagonal weave on the webbing nets there is no transferring of the load to a border. The lacing around the net is attached directly to the net straps, or to a batten inserted through the straps. All of the loads are on the webb strapping, not on stitching, grommets or attached reinforcement. The nets are a continuous weave which means there are no webbing ends near the perimeter of the net.
We recommend, and use, the Gore-Tex Tenara thread in all the exposed stitching on all of our nets. We do however offer Beach Cat trampolines with the option of a lower cost polyester thread. The Gore-Tex Tenara thread is made of 100% PTFE, and is completely impervious to UV degradation and other elements found in the marine environment. W.L. Gore & Associates, Inc. guarantees their thread will outlive any material it is used on. The importance of this cannot be understated, as any net with a border relies on the strength of the stitching to hold it together, and thread made of all other materials deteriorates in the sunlight at an alarming rate