April 17, 2012
SailPack, the sail design program we use at Maine Sailing Partners, is an extraordinarily powerful design tool that allows us to look at sails and boats in a way that not many people can. For instance, there's this:
a Crowther 46 catamaran with a rotating wing mast with diamond shrouds. How do we design a jib that will sheet and trim properly and be sure that it won't interfere with the mast rotation? Using SailPack, we can bend the jib onto a virtual Crowther 46, check the rig, check the trim, and look at the whole thing like this:
Multiple views and very useful tools.
February 09, 2012
The first steps in creating a sail here at Maine Sailing Partners take place in the virtual world - the world of sail design software. Here is a quick visual overview of the design process, in this case for the mainsail of a 36' racer cruiser:
Step one: develop the basic outline of the sail.
February 02, 2012
Interest in code zero sails has grown steadily since they first appeared in the 1997/98 Whitbread as light air, close reaching sails. Their relatively flat cross-sections and large overlap make them especially effective from about 45 to 75-degrees apparent wind angle. No longer considered just a light air sail, a code zero can be used anytime the addition of more horse power can make the boat go faster. This is a narrow niche for some boats, but there are many boats that can benefit from additional sail area when close reaching.
To prevent sailmakers from building oversized genoas, PHRF considers a code zero a spinnaker so the mid-girth must be at least 75% of the foot. PHRF also penalizes boats that carry code zero sails - 6 seconds per mile for boats that carry genoas with LPs of less than 130% of J and 3 seconds per mile for 130% or greater. This pretty much limits the usefulness of code zero sails to long reaching races where the improvement in performance overcomes the penalty.
It's a different story with cruising boats where there are no such restrictions or penalties. Here we can take advantage of innovations in code zero laminates, continuous line furlers, and anti-torque luff ropes to make sails that don't comply with the racing rules and can't be penalized but are as easy to use as roller furling genoas and very effective windward reachers.
Finally, there is a loop hole if you race a classic yacht in CRF regattas like the Eggemoggin Reach Regatta. Provided your boat is already rated for a spinnaker, these kinds of sails are treated as a spinnakers no matter what the cut and without penalty provided they aren't set on a permanent stay. Such a sail could be devastatingly effective anytime it's too tight for a spinnaker but you need more power than you can get from the genoa.
January 03, 2012
I like to see the previews when I go to the movies. I think that most people would like to see what their new sails will look like before they're delivered. Now you can preview your sails in your email in-box. SailPack Viewer is an interactive program that gives you a 3D preview of your sails.
Particularly useful is the SailPack Viewer feature that allows you to customize your spinnaker colors and panel layout.
April 20, 2010
One of the things that we work hard on are the little details that make the sails we build work well. Here's a look at the luff reinforcing patch for a mainsail:
Six radial layers with strong fill in the radial direction with 3 layers of very heavy, very firm fabric under them. The corners and reef reinforcements are the most heavily loaded parts of the sail. We build our reinforcements to minimize distortion at those points. Minimizing distortion is the key to both proper sail shape and sail longevity.
Here are the rest of the reinforcements for the sail:
April 07, 2010
ServiceWith our tunnel vision it's hard to fathom, but we are discovering that some sailors don't know that, in addition to building sails, we also provide complete sail service. So we're spreading the word, by distributing our new sail service brochures to boatyards around the state. Feel free to click the link and download your very own copy.
March 29, 2010
The year of Hydra-Net
So far this year, we seem to be inundated in Hydra-Net radial sail projects: a Deerfoot 65 mainsail to New Zealand, a Little Harbor 52 main and genoa bound for England, a Voyager 64 catamaran inventory for here in Maine, a Taswell 56 inventory for the Atlantic grand tour, a White 42 catamaran mainsail for the South Pacific, a J/42 inventory for Finland.
Hydra-Net is a single layer woven Dyneema polyester hybrid. It's advantages are low stretch, excellent UV resistance, refusal to harbor mildew. It is a hands down choice for performance cruisers from 40 to 70 feet who want bullet-proof construction and enduring good looks.
It's such tough stuff, that Ken hates to cut it, but other than that we love the stuff.
June 10, 2009
Actually these Landing School 30 mainsails are fraternal twins. The mainsail on the left is an aramid custom load path D4 MP sail. The mainsail on the right is made of aramid FLEX13A. The boats are currently at the Maine Yacht Center undergoing final preparations for launch.
May 06, 2009
Landing School 30 D4 MP mainsail construction
D4 MP is Dimension-Polyants' custom load path laminate for boats 40' and under. Load yarns are laid out on 60" wide panels before lamination. MSP's design is then plotted onto the panels. Dimension-Polyant can assemble and glue the panels although we do this ourselves at Maine Sailing Partners. Here, we are assembling the individual panels to a Landing School 30 mainsail. Here we are checking the sail for any assembly or cutting errors before gluing. We didn't like the way the third seam from the top looked so we took it apart, put it back together, and checked it again.
. After double-checking the sail shape, we mask the seams and glue them with DP's Ultrabond hot glue. Here, Ken is driving the glue gun, and I'm driving a squeegy. It's not very high-tech, but it makes a very smooth and strong seam.
This is the completed blank ready for finishing. Here's another view of the same Landing School 30 mainsail. Note the square head.
April 07, 2009
Sailcloth comparisons: how we see it
Here's an e-mail exchange with a curious customer.
Thank you for the revised quote on the sail for my boat. I have a few quick questions trying to compare things. What are the differences between Dimension Polyant 280 AP 6.5 oz Dacron and 7.7 oz. Challange Marblehead Dacron for a crosscut dacron sail? What are the differences Dimension 310s Seatec square Dacron and Dimension Polyant TriRadial 6.5 oz Dacron in a TriRadial and finally what are the differences between Dimension Polyant CX7T Laminate, 8.1 oz Dimension Flex C 16 polyester laminate w/taffeta and North's Norlam for a laminate crosscut sail?
Sorry for all the questions, just trying to get a better understanding of the various sail cloths and the pro's and con's of each fabric and the various sail configurations.
Thank you for your help.
Don’t apologize for asking questions about sail fabrics. A quality fabric is the key to the performance and durability of your sail, after all.
First of all, both Dimension Polyant and Challenge Sailcloth make high quality fabrics – meaning they are well engineered, and tightly woven, from high modulus yarns.
The DP 280 AP 6.5 oz. is a 250 denier (warp direction) by 440 denier (fill directions) weave that weighs about 6.5 oz. per sailmakers yard (36” by 28.5”). The Challenge 7.77 is a 300 x 440 weave weighing approximately 7.5 oz per sailmakers yard. In a cross cut layout the fill yarn is aligned with the leech. In a high aspect sail, like a mainsail or blade jib, the loads are concentrated along the leech so the fill yarns are doing most of the work. In a lower aspect sail like a genoa the loads are more spread out, so a more balanced weave like the Challenge product helps the weave structure handle off thread line loads. That said, the DP product is not as unbalanced as some weaves designed only for high aspect sails.
The DP 310s is a ripstop construction with a base weave of 250 x 250 interspersed every half inch with a pair of 1000 denier yarns in each direction weighing about 7.2 oz/smy. The advantage of this structure is that the basic weave can be very tight (meaning the threads are heavily crimped implying some stretch in exchange for good off thread line performance) while the 1000 denier ripstop yarns can be held very straight for good thread line stretch resistance. This is a very balanced weave and its strength in the warp direction, a rarity in woven fabrics, makes it appropriate for radial constructions, where the warp yarns are well aligned with the loads, especially in a low aspect sail where those loads are widely spread. I am not sure just which fabric is meant by DP 6.5 oz Dacron. The closest would be their 6.2 oz 265s.
Laminates can be more stretch resistant because their structural yarns do not need to be woven. Instead they can be laid straight before being laminated between layers of Mylar film. Having no crimp from weaving, they have very low initial stretch. Moreover, the structural yarns are not limited to warp and fill directions. Both the DP CX7T (8.4 0z/smy) and the DP Flex 16 C (8.1 oz/smy) have some off warp and fill yarns (generally referred to as x-ply). The CX is designed to be strong in the warp direction and slightly off warp – x-ply at plus and minus 6 degrees from the warp. This fabric is designed for triradial construction. We used it for many years with great success. The Flex is a newer style with x-plies at 20 and 30 degrees to the fill and is designed for crosscut construction with the x-plies providing support for the off thread line loads. When built with this fabric, a cross cut sail behaves very much like a triradial sail. Flex, by the way, is an acronym for Fill Laminate Extra X. The main advantages of crosscut Flex sails as opposed to triradial CX sails are that the cloth utilization is more efficient and that the shaping is all confined to seams perpendicular to the principal loads in the sail. Better cloth utilization means that although Flex costs more than CX the sails are less expensive. Cross load shaping means the sails are generally smoother than the triradial sails. That said, the CX sails may have slightly better initial stretch resistance, but our testing shows better long term performance from the Flex sails.
I am afraid I can’t give you any information on the Norlam crosscut laminate. In the past, their warp oriented laminates have not included any unwoven yarns but relied solely on the external taffeta for stretch resistance (with no off thread line support beyond the film).
The only negatives to laminates in general are weight and mildew. At least for boats in your size range, the structure of cruising laminates, two layers of film, two layers of taffeta, and the base structural yarn framework, plus laminating adhesive, add up to extra weight, not all of which adds to performance. Cruising laminates can on rare occasions become seriously contaminated with molds or mildew. Because of the laminate structure, these contaminates can be difficult to remove completely. Although they have no structural effect on the sail, they can be unsightly.
I hope this answers you questions. Please don’t hesitate to call if my answers above have left you more confused.