Genoa - crosscut vs radial

[michael_w]

Consider Hydranet. After two lots of appalling service I would never go to North UK.

 

[richardbrennan]

I have exactly the same sail as Javelin from North, which was new three years ago. The boat is a Westerly Ocean 33, so quite similar to a Storm. My understanding from North is that before the development of their low stretch Dacron, it was a waste of time having a tri-radial genoa. The sail sets very well, is not expected to go baggy as with a standard Dacron sail cloth and the service from North was excellent, albeit I am just down the road from the loft in Gosport. The cost was about £2500.

 

[geem]

Its interesting all this chat about sails and how long they last. In cruising boat sailing I prefer to talk about sail life in thousands of miles. When somebody says their laminate sail lasts so many seasons its on no use if they only did 5nm each season! We find that dacron sails last about 20k nm. They are stretched out by then and a mainsail is also worn on the luff and other places due to reefing. At this point they need replacement. I dont think the cut of the genoa is relevant to life. They are just all knackered by this kind of mileage.
We have just ordered Vectran sails. In theory they should last about 40k nm if you can keep the chafe under control. High wear area on our sails will be reinforced with hydranet.
Our experience of cruising laminates was not a good one. They failed after four years and 6k nm. Our friends also failed at the same mileage and age. Both were subjected to Caribbean UV.
We were persuaded to keep away from Hydranet. Its super durable but very stretchy. They dont wear but they go baggy quickly.
Our current set of Dacron sails, main and genoa ( soon to be replaced) did 27k nm in 6 years and are well past they sell by date. We hung in there with them until we got back to the UK knowing they were worn out. They didnt let us down but we had them restitched and repaired before we left the Caribbean and stuck an extra 4k nm on them to get us home

 

[Steve The Seagull]

This is a good thread and is a nice example of the variety of thinking and options available in the sailmaking market. It also reinforces though that what works for one design of boat, sailing in a certain set of conditions does not necessarily work for another, and it is important to remember that.

In answer to your original question, radial is generally worth it, especially on genoas. The caveat is that the cloth must be of good quality, it is better to go for a high end cross cut sail than a low end radial sail. You mention Pro Radial, but all 3 major cloth manufacturers (Contender, Dimension Polyant and Challenge) all have cloth called Pro Radial and it sits in a different quality range for each brand. The radial genoa will hold its shape better over time and especially when the breeze comes up, upwind performance is the major gain.

Cruise Laminates - Modern cruise laminates are very good, but they have an intended use and if used outside of that (like long distance cruising in hot climess) they might very well not perform. They are light, low stretch and relatively durable.

Vectran - it is a good product, a tad overrated I feel though sometimes, it works well in high aspect sails where there is a large amount of vertical loading.

Hydranet - A sometimes misunderstood cloth as it both has a cross cut and radial version! The crosscut version if used wrong can end up stretching in some strange ways, and is thus generally not used much. The radial cloth is very good, low stretch, durable, great for blue water sailing, and bigger, higher loaded boats.

Membrane and Filament Products - These are the muts nuts, fibers aligned in the load paths, allowing better shape holding and less weight and with the ability to specify the fiber and exterior (film, taffeta, liteskin, Raw etc….) are totally customizable to the boat, which is very cool. I love making sails this way, but they have a place and…… a cost

 

[matt1]

I wouldn’t waste money on combining Tri Radial with Dacron cloth. You are just adding weight and cost for very little benefit. I’d go laminate and echo what Flaming and others say; Laminate will hold its shape much longer

 

[Concerto]

I have no racing experience but I'm keen to get the best out of the boat, so I do intend to pay due attention to sail trim, and continue to learn.

Basically a genoa is easy to set up. You can adjust the halyard tension which moves the flow further forward with more tension, having a horizontal black line assists in seeing where the maximum chord is, is essential.. The sheet adjusts the angle of set to the wind and finally the genoa car alters the leech and slot to the mainsail.

The more difficult to set is the mainsail. On my Fulmar being ¾ rigged, this is the main driver for the boat. To assist setting I have a fully battened mainsail, so you have to get the correct tension on each batten. The halyard works the same as a genoa. The clew is supported on the boom and works a bit like the sheet, but you have a few further controls. The mainsheet controls the angle to the wind. The kicking strap (I use a solid kicker) controls the twist in the main, but this can be further adjusted by the traveller. Getting all 4 leech tell tales to fly aft without back winding takes a lot of effort to get right.

The final thing you also have the get tensioned is the rig. I use a Loos gauge and my rigging is bar hard. A slack forestay will cause the genoa to be too baggy.

That is the very basic theory to make your boat sail faster. Putting it all into practice is not difficult, but then learning to helm using the tell tales will make you sail even faster. Keeping the bottom clean is also worth doing for extra speed. The final extra you can purchase to get a boost in speed is to fit a folding propellor. Everything combined should add about a knot to your boat speed or an extra 12 miles in 12 hours sailing or arrive 2 hours earlier than before. Getting every bit of extra speed is worth doing. I regularly out sail boats 3 to 5 longer as I pay attention to sail trim, much to their annoyance as I am also singlehanded.

Your Storm, is it the full rig or the cruising rig? If the cruising version, is it a fin or twin keel? My Fulmar is a fin for faster sailing.

 

[Chae_73]

Thanks Concerto, food for thought.

Our Storm is an OOD so has the larger mast head rig, backstay tensioner and fin keel.

Folding prop is on my list but planning to re-engine next winter so will look at props then. The boat currently has the original Volvo lump which is still reliable but clearly long in the tooth.

 

[fredrussell]

...The final thing you also have the get tensioned is the rig. I use a Loos gauge and my rigging is bar hard. A slack forestay will cause the genoa to be too baggy...

Is this on the advice of a rigger or just your own preference? My previous boat was used by then owner for racing and rig was tuned by the local chap. I wouldn’t have described it as bar hard, though obviously that phrase is subjective.

 

[Chae_73]

In answer to your original question, radial is generally worth it, especially on genoas. The caveat is that the cloth must be of good quality, it is better to go for a high end cross cut sail than a low end radial sail. You mention Pro Radial, but all 3 major cloth manufacturers (Contender, Dimension Polyant and Challenge) all have cloth called Pro Radial and it sits in a different quality range for each brand. The radial genoa will hold its shape better over time and especially when the breeze comes up, upwind performance is the major gain.

Hi Steve
thanks for the detailed response. Having check the quote, the fabric suggested is in fact Dimension Pro Radial


Pro Radial - Dimension-Polyant

 

[johnalison]

I wouldn’t waste money on combining Tri Radial with Dacron cloth. You are just adding weight and cost for very little benefit. I’d go laminate and echo what Flaming and others say; Laminate will hold its shape much longer

There appear to be differing opinions about the durability of laminates. Several of us have got extended use from them, while others have had early failures. I don’t know how many of the failures were from earlier versions. It believe that laminates have improved, as have other cloths. One cause of my first laminate’s decay was the use of a sail cover. It was some time before I could see that friction was abrading the taffeta. In spite of this, it lasted twelve years or so. I never saw any sign of delamination after sailing 2,000 plus miles per year, but there were some small tears down the leach at the end.

A slack forestay is undesirable, but not necessarily fatal if the sail has been cut to compensate, as was the case with traditional boats such as Dutch barges.

 

[Concerto]

Is this on the advice of a rigger or just your own preference? My previous boat was used by then owner for racing and rig was tuned by the local chap. I wouldn’t have described it as bar hard, though obviously that phrase is subjective.

The set up is a combination of experience from my racing days, a rig set up guide from Proctor Masts dated 1984 specific to the Fulmar, and guidence from Loos on how the set up a ¾ rig (http://loosnaples.com/files/PDF/INST-07.pdf). So, not just my preference.

The ¾ rig on the Fulmar has means the tension on the forestay is from the cap shrouds via the swept back spreaders. The sail plan from the original 1979 brochure shows the rig set up quite clearly, but also shows an inner forestay that was never fitted.



There is 6" of prebend in the mast fore and aft and controlled by the single lower shrouds using the same deck fitting as the cap shrouds. The backstay is quite slack as that will only induce more bend in the mast, unlike a masthead rig which is tensioning the forestay. Loos recommend all masthead rigs have the tension set to 15% of the breaking strain of the wire, but for a ¾ rig the cap shrouds are set to 20%. The only description I can say about the difference is a masthead is tight whereas my ¾ rig is bar hard.

Finally to answer your question, I do not use a rigger as I feel I have sufficient experience and knowledge to know how to set up my rig correctly.

 

[Steve The Seagull]

I wouldn’t waste money on combining Tri Radial with Dacron cloth. You are just adding weight and cost for very little benefit. I’d go laminate and echo what Flaming and others say; Laminate will hold its shape much longer

I must disagree in part with this. Low end radial Dacron is not worth it, but the high end products, like Dimension Polyant Pro Radial are most definitely a very good cloth. For extended cruising in boats under 40 foot it works very well.

 

[fredrussell]

...Finally to answer your question, I do not use a rigger as I feel I have sufficient experience and knowledge to know how to set up my rig correctly.

Cheers, that’s interesting. Doing (or getting done, depending on finances) my standing rigging soon - just gathering info currently. I definitely don’t have the know how to tune a rig so will get a rigger in for that part.

 

[Concerto]

Cheers, that’s interesting. Doing (or getting done, depending on finances) my standing rigging soon - just gathering info currently. I definitely don’t have the know how to tune a rig so will get a rigger in for that part.

This short video from Loos is worth watching. Personally it is worth buying your own tension gauge like Loos. They do appear occassionally on eBay, but best to set up a search to notify you when one is listed, that is what I did. I now have two different sized ones as the smaller one would not tension my caps at 20% even though it took 6mm wire. If you come down to Chatham Marina, let me know and I will be happy to lend you a Loos gauge and help if necessary to set your rig up.

 

[Daydream believer]

The comments re cross cut & radial surprise me. Obviously cloth construction has changed over the years so my earlier understanding may be well out of date.
However, I was always of the impression that basic dacron was woven with the main thread running in one direction with the cross weave at right angles. This cross weave going up & over the main weave allowed stretch because it was not a straight line . Therefore, the cloth is generally designed to take the strain in one direction rather than two. Thus with a simple cross cut sail the diagonal stresses that occur would apply stresses across the cloth & thus along the weaker weave. Accordingly the cloth would gradually stretch
To offset this, sailmakers designed tri radial sails. In this design the cloth was laid such that the stronger weave lays along the stress lines of the sail. The weaker weaves not having so much stress applied to them.
The theory being that a tri radial sail would be less likely to stretch so much as a cross cut sail.
So on a sail like a 150% genoa with large cross cut panel the advantages of tri radial design would be obvious. On sails where the panels are smaller the advantages are not so great. A cheaper sail may have larger panels with less stitching & less labour.
Also the weave might be wider apart with more resin to bond the weave. The sail flogging would crack the resin around the weave & the sail would then start to stretch
So i would look for a closely woven cloth with less resin. I would fold a sample cloth & crease it hard with the back of a steel ruler or similar to see if the resin cracks. then flex it the other way & repeat to see what happens. It is amazing how different cloths used to react to this simple test at boat shows
Of course things have changed & i am well out of date.
Now I go to my trusted sailmakers who visit my boat, Measure & discuss the design . Cut the sail how I want it, with a cloth that i can chose. Or at least a designer with a track record on that type of sail- ie Hyde for my squib, Ultimate for a blade sail , Lonton & Gray for all the accessories, covers etc

 

[Daydream believer]

would not tension my caps at 20% even though it took 6mm wire. If you come down to Chatham Marina, let me know and I will be happy to lend you a Loos gauge and help if necessary to set your rig up.

On my Hanse my caps are set at 24%. I am not letting on what the mids & lowers are, but the performance difference upwind once i found the best set was quite marked. The mainsail cut to suit mast bend

 

[Pete7]

I must disagree in part with this. Low end radial Dacron is not worth it, but the high end products, like Dimension Polyant Pro Radial are most definitely a very good cloth. For extended cruising in boats under 40 foot it works very well.

That's interesting, would you recommend the DP Pro Radial cloth over Vectron possibly cross cut or tri-radial?

 

[Steve The Seagull]

That's interesting, would you recommend the DP Pro Radial cloth over Vectron possibly cross cut or tri-radial?

Generally yes.
Vectran is a crosscut only cloth, good for certain applications, generally higher aspect sails.
DP Pro Radial is currently the best radial woven polyester cloth. It successfully took Jean Luc Van Den Heede around the world in the Golden Globe Race. It's very well woven, finished and highly regarded.

 

[Pete7]

Generally yes.
Vectran is a crosscut only cloth, good for certain applications, generally higher aspect sails.
DP Pro Radial is currently the best radial woven polyester cloth. It successfully took Jean Luc Van Den Heede around the world in the Golden Globe Race. It's very well woven, finished and highly regarded.

Thank you, I suppose the other question a customer wants to know, are they much of a muchness in term of price?

Pete

 

[Chae_73]

Pete

The prices that I have for 135% genoa for a 33' masthead sloop go up in approx £500 increments, roughly:

Crosscut in Contender Fibrecon pro -£1,500
Crosscut in DP Vectran - £2,000
Tri radial in DP Pro Radial - £2,500
Tri radial in DP Hydranet - £3,000