Nets are designed to be fully tensioned to provide as firm a surface as possible. To accomplish this, the attachment method and hardware needs to be sound enough to handle the load. Lacing is the most common method and requires fasteners or lacing points to be installed on the boat. There are many acceptable fastening systems in use. Lacing slides in track, a grommeted boltrope strip in a track, or offset rails (wood, aluminum or stainless steel), allow some flexibility to move lacing points around as needed. Eye straps screwed or riveted in, and holes drilled in a hull or deck flange also work but are less flexible requiring lacing points to be precisely defined. Number 10 screws set with epoxy or a good adhesive/sealant will work in a solid surface (not a lightweight core). Spacing should be every 8" in sheer (decks) and every 6" in tension (hulls), or less. Use 3/16" or 1/4" rivets in aluminium crossbeams. Not all sides of the net need to be laced. In mesh materials, one to three sides can be supported with a boltrope sewn into the net that would slide into a track. Mesh materials and webbing nets can be supported by cables on one side or two opposite sides. Cables (3/16" to 1/4" coated) will receive much greater loads since they support the entire side and should be mounted with through-bolted pad eyes. To reduce the loads and increase the firmness of the net we recommend the cables be sized to allow at least 5/8" of curvature for every foot of length with a corresponding curve designed into the net.
Installation Hardware
Boltrope Track
Mesh nets can be supported on one or more sides by boltrope which would slide into track mounted on your hull, deck or cross beams. Our Aluminum Track is extruded especially for Sunrise Yacht Products with a heavy .090" wall thickness. It is finished with a marine quality clear anodizing to prevent oxidation, and a 1/2" diameter. There are two versions for mounting on vertical or horizontal surfaces. Both of these tracks are available in 8', 12', 16' and 24' lengths (only 8' can be sent UPS).
Deck Track
Hull Track
Lacing Slides
All nets must lace on at least one side and webbing nets usually need to lace on all 4 sides. Lacing slides work with a track to make movable lacing points. These slides are strong nylon slugs molded around an 1/8" stainless steel ball which can have one 1/4" line or two 3/16" lines. They are avalable in several diameters for different size tracks.
Other installation hardware available
· Stainless steel eyestraps
· Fiberglass battens for sleeves or webbing nets
· Lacing Line
· Flat base stainless steel lacing slides
Net Lacing Examples
Alternate Lacing
The line zig-zags from boat to net with grommets located midway between lacing points on the boat. This is the best for grommet hems, or webbing nets where the lacing points are 6" or less apart. It is the easiest to tension.
Perpendicular Lacing
Here the line travels alongside the hull (deck or beam), then through the lacing point to the net and back, through the same lacing point and then along the hull again to the next lacing point. This type of lacing is usually used with the pipe sleeve borders, where lacing points are 6" to 12" apart, but also could be used with grommets or on webbing nets. Since the line makes a perpendicular to the net, the lacing gap has no effect on net tension and could be smaller than the standard 3". The lacing points will need to be large enough to allow the line to pass through twice.
Double Lacing
This is an alternative for grommet borders where lacing points are spaced from 6" to 12"apart. The line must pass through each lacing point twice.
Webbing Net Battens
The above drawing shows a 2" webbing net with 3" average gaps. 5/8" battens are inserted through the webbing folds along the edge of the net. This would then be laced by either the alternating or perpendicular method. The use of battens allow the webbing to lay flat and minimizes the possibility of chafing. It also eliminates the need to lace directly into the corner.
WEBBING NETS
Webbing nets provide the firmest, strongest surface with solid footing and the least amount of sag. The Nets are diagonally woven, with 1" or 2" wide webbing, so the loads are transferred back into the net rather than dead ending at the border. All stitching on webbing nets is done with heavy Tenara (Gor-Tex) Teflon Thread. The 2" webbing nets are stitched along both sides of each length of webbing boxing in all intersections, while the 1" webbing nets are heat welded at each intersection and stitched only at the first intersection in from the lacing.
Webbing nets can be woven with various densities, generally an average gap size within the net of 3", 2 1/2", or 2" with 2" wide webbing and 2", or 1 1/2" with 1" wide webbing. These nets can be laced directly from the webbing folds along the border, or from a rod or tube inserted through the border. One or two sides of the Net could be supported by coated cable with no lacing. The webbing we use is either black polypropylene or white polyester. The polyester is about 4 times stronger than the polypropylene, however polypropylene, in black, will lose strength at a slower rate than polyester and will not fade.
Webbing Net Material
2" Black Polypropylene
Characteristics
The most economical webbing nets suited for non-commercial boats of all sizes. We use the thickest, strongest polypropylene webbing available. This material does not fade and will maintain its appearance throughout its life.
2" 3Ply
Made with black polypropylene top and bottom and white polyester in the center or with 3 plys of white polyester, the outer layers become sacrificial and the center layer (4,000 lb. breaking strength) is protected from UV degradation. These nets can be reversed when the top ply begins to show wear to extend their life. The additional strength and UV protection make these nets suitable for charter work or full time cruising use.
1" Webbing Nets
Made with a single ply of either black polypropylene or white polyester. Using 1" webbing allows for the same openness with 1/2 the gap size throughout the net which makes these nets considerably more comfortable.
It is possible to apply a vinyl coating to any of the polyester webbing nets which will give them a non-fading color and added UV resistance. This is an extremely elastic latex coating which is thinned to saturate the material and is applied, with the net under tension, in two separate applications to both top and bottom. The standard colors available are black, white, grey, light blue, pacific blue, dark blue, navy, aquamarine, persian green, forest green, burgundy and red.
MESH NETS
These Nets are made from a variety of fabrics with a varying degree of openness for different applications. They can be made to fit any shape with grommet, pipe sleeve, or webbing tab lacing or depending on the stretch of the material 1 to 3 sides may have boltrope or cable sleeves without lacing. All meshnets are constructed to compensate for the material stretch by under cutting the mesh by a specific ratio and stretching to fit the border material.
Mesh Material
Coated Polyester
Our Polyester Mesh is knitted with approximately 5/16" holes on 1/2" centers. This makes it a comfortable mesh with an openness comparable to webbing nets. This material is coated with a single application of the same vinyl coating used on the webbing nets. Not as strong as webbing nets, this material is suitable for moderate use in areas up to 80 square feet.
Square Hole Mesh
This is a woven mesh with 1/4" wide fibers and 1/4" holes. It is coated with a hard vinyl coating in white only. The openness of this mesh is slightly less than the Coated Polyester Mesh but it is considerably stronger. This mesh comes in a limited width, so any nets with the narrower dimension of more than six feet would have to be seamed.
Polypropylene
This woven mesh, available in either black or blue, is extremely durable. Most mesh trampolines are cut on the bias (fibers at a 45 angle to the border) which greatly increases the holding power of the grommets, and allows the use of boltrope on all but one side to reduce the amount of lacing. Because of the low openness this mesh is not recommended for bow areas of offshore yachts, but works well on more central locations. This is the preferred material for beach catamarans. And our experience and skill in high quality fabrication with it is unsurpassed.
Open Netting
An extremely open knotless nylon netting, available in a light duty style with 3/4" holes or a heavy-duty style with 1 3/4" holes. This net is not as comfortable and has more stretch than the other types of netting but is well suited for areas where minimum windage and water resistance are a priority. This netting is also coated under tension with a single application of our vinyl coating for color and UV resistance.
Some examples of Nets that look good . . .
Boltrope plus Lacing
If you have a new idea with relation to nets on Multihulls please send us a picture for inclusion in our construction site.
We would like to thank Sunrise Yacht Products for the use of some of the material used here
