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Thanks John!!
Hello,
Thanks for this short article announcing the rest.
Are there inconveniences of triradial cut for in mast furling mainsails. Some advise cross cut as a better choice if I understand that the number of overlapping stitches when furling make the tri radial cut sail thicker and more difficult to furl. Is this true?
Hi Denis,
Hum, I have never heard that. My best guess is that’s unlikely to be a problem. Anyone else have good verifiable information on this?
If anything, I would say radial cut is *more* important on an in-mast furling main than on a conventional one. You’ve given up the battens and cut it to a concave leach in order to make the furler work; keeping a reasonably efficient shape for what’s left of the sail is now that much more important.
I would extend Matt’s observation to favor radial cuts for the jib, if the crosscut main (without mast furling) cost is high and the budget is small. Holding Jib shape is more important because there are more adjustments for the main (with two spars). The main cross cut can be recut reasonably easily.
Does anyone have experience with re-cutting a tri-radial? I know with the improved load distribution, they hold their shape longer, but Dacron does stretch over time.
Hi Ben,
Of course I’m out of date, but I think it would be difficult and costly to recut a radial sail. What shape problems is it showing?
Hi again Ben,
Also, how old is the sail and does it have any evidence of sun damage? Back when I was sailmaking people would often insist I fix/recut old sails, often over my objections, and then get mad at me because the sail failed again, or did not look much better.
Generally, if the sail was well designed in the first place and tri-radial my thinking would be that when it starts looking terrible it’s probably not worth putting a lot of money into. Sun damage, particularly weakens the fibres in ways that cause the sail to distort.
AFAIK that’s something that just isn’t really done. If a bi- or tri-radial sail is made properly in the first place, then by the time it’s stretched enough to need re-cutting, the dacron has also experienced enough UV deterioration to not be worth re-cutting.
Dacron is just polyethylene terephthalate. It will eventually break down from wear and sunlight just like any other polyester / PET variant.
How about a Mitre cut sail . Especially one that is high footed like a Yankee ?
Hi John,
Good question. Mitre cut was the answer we used back in the day to get the panels at 90 degrees to the leach and foot , particularly with high cut sails (as you say). I designed and made several of them back then. However miter cut is not a patch on radial because most of the loads are still running on the bias of the fabric. The classic way this manifests is the cloth stretches each side of the miter resulting in the classic “elephant ass” problem. Bottom line, radial replaced miter, because it’s way better.
So the question would be is a mitre cut better for a yankee then a crosscut ?
Hi John,
I guess miter cut, but only marginally. Radial is the way to go, and now we have computerized cutting tables probably not a lot more expensive than miter cut.
Yes my sail maker quoted me a mitre cut , but I will get a price on a radial as well . Time for new set of sails .
Thanks John
Hi. I get that 3radial cut is the way to go with genoa or jib. But what about mainsail? I have moved down from 39 feet sailingboat to a 33 feet cruising boat with 22 square meter mainsail. Would not a crosscut mainsail in good dacron quality, with long battens be good enough?
Hi Lars Erik,
I’m not educated as a sailmaker, but did work a bit for some in the nineties and have many decades experience with using sails heavily. FWIW, I’d say the answer to your question lies in your own definition of “good enough”. No matter what, you’ll certainly get less performance and a shorter use life out of a cross cut dacron main than a radial cut one in the same cloth. The question is if you think improving that is worth the extra money.
I’m also not an engineer, but in this case, with a quite small main, you may benefit some from a scale effect. If I’m right, a smaller sail will have comparatively thicker cloth than a larger one, while the loads also diminish more than the difference in area would indicate. Thus it may be a bit less vulnerable to the weaknesses of the cross cut layout. Still, I’d go for radial cut, if I could choose.
Hi Stein. Yes good enough was not a good statement. The question should rather be, Is a tridaial mainsail to this boat so much better that it is worth the exstra money?
Hi Lars,
As I say in the tip, I would always go for a modern radial cut sail because it lasts longer, or at least stays well shaped longer, which to me is the same thing. I’m also not sure I agree with the general idea that radial is less important for mains than jibs. In recent years, and even when I was sailmaking, we have come to understand more about how important good shape (usually quite flat) in the mainsail is for good performance at low heal angles and radial will always do better in this regard, because a cross cut main will distort in ways that move the max camber aft and tighten the leach in ways that make my teeth hurt to look up at.
Bottom line, it all depends on what your personal definition of good enough is. To me cross cut just is not good enough, so I will always prioritize money on good sails ahead of anything else except safety items. More on priority here: https://www.morganscloud.com/2009/11/01/dont-forget-about-the-sails/
Hi
Just compared two quotes for my main:
Dacron, cross cut, usuall battens ~ £ 1400
Hidranet, radial, full battens : triple the price
Do you think it is worth it? Or do I just need to find a cheaper sailmaker? : )
Hi Ignat,
Wow, hard call, I sympathize! That said, given that I’m also a huge full batten fan, I would probably go for it on the basis that the cost per mile will actually be lower. That said, I would certainly get a couple more quotes to make sure you are not dealing with the all too common situation where the sailmaker does not want to make the more complex sail and therefore prices accordingly. The other thing to check is if they have a computerized cutting table. If not that will explain the price jump.
Hi Ignat,
I agree with John. I would also ask whether they have a history of making sails using HydraNet Radial. The material is more difficult to work with and the use/design of their different weight/strength clothe in strategic areas might mean you are paying for the loft’s learning curve.
My best, Dick Stevenson, s/v Alchemy
Hi Dick,
Another good idea for a possible reason for what seems a crazy uplift.
John,
I’ve been shopping for new sails for my J/40, and had an interesting conversation with a sailmaker from a large loft, who actually tried to steer me away from a tri-radial mainsail for my boat. Ultimately he was trying to upsell me into a loadpath membrane sail, but even after telling him that was out of my price range, he was still pretty steadfast, that a tri-radial is not right for my boat and planned sailing style.
I am planning an extended offshore cruising trip, likely multiple years. The sailing will be almost exclusively short handed, my wife and I, or myself solo. His explanation (doing my best to paraphrase) was that I will do a lot of sailing with the main reefed (seems reasonable), and the forces applied to a reefed dacron or laminate tri-radial mainsail with adequate outhaul tension, will apply tension to the sail in a manner it will struggle to deal with and the foot and leach will stretch horizontally. In order to overcome this, the clew reefs would need to be dramatically overbuilt making the sail difficult to manage, especially short handed. A crosscut main is a compromise, but building one out of the highest quality dacron available, is a better option for my boat and use than a tri-radial, especially because my mainsail is relatively low aspect (~2.5).
Curious to hear your thoughts on this theory.
thanks,
Adam
Hi Adam,
Interesting, but that’s not been my experience. As I say in the tip, Tri-Radial has worked great for me for 30 years and I have always reefed a lot. In fact I would guess that more than 50% or our sailing hours were reefed. And I always had the foot bar tight to get good shape when reefed.
Note that we used low stretch material: https://www.morganscloud.com/jhhtips/my-favourite-cruising-sail-cloth/
You can see that our sailmaker has built really beefy patches for the reef clews, but that should be done for any offshore boat, and that has never caused handling issues. Also note he has a strip of fabric along each reef foot. And if memory serves, he makes the leach panels out of a bit heavier cloth.
Also if he thinks that radial will stretch too much when reefed how can he justify cross cut since the load paths will be on the bias, the worst direction for a woven cloth?
And check out the shot showing our main after many hundreds of hours reefed.
Here’s another shot of the main with two reefs and showing good shape: https://www.morganscloud.com/2014/11/17/your-mainsail-is-your-friend/
Also, to be blunt, I would be sceptical of any sailmaker who would even suggest a load path membrane sail for long distance cruising. I have sails like that came with my j/109 and yes they have great shape…until they fail spectacularly, a disaster at sea.
If you are in the USA, maybe have a word with our sailmaker about a quote: https://www.morganscloud.com/2009/11/18/how-we-buy-sails/ Ask for Richard.
Thanks, John. I appreciate your advice and also taking the time to respond with links/photos.
Hi Adam,
I think John will also answer this, and I’m no sailmaker (but have dabbled quite a bit with it), so FWIW: I don’t think what the mentioned sailmaker said is entirely right. Also not completely wrong, but… the conclusion seems totally wrong to me.
By far the biggest loads on the mainsail is at the clew and head. The load path between those two is of course what the cloth layout must be designed to deal with. The horizontal along the boom, the diagonals through the middle of the sail and the luff along the mast also take significant loads, of course, but they are all much smaller loads.
When the main is not reefed, a radial cut sail will have the cloth very well aligned with all main load directions in the sail. When reefed, your source is right that some of that alignment is lost. Especially the one parallel to the boom. However, the path between clew and head, the aft part of the sail, the heavily loaded part, stays quite well aligned no matter how deep you reef. The whole top of the sail always stays well aligned.
If I were to translate what your source claims, it might be something like: “No point in perfecting something if it gets a bit less perfect when reefed. It’s better to use poor cloth and orient it so it’s always misaligned.” I rest my case…
A pet peeve of mine, relevant here: Reinforcements of reefs are sized gradually smaller, to represent the smaller sail area left in the main. That’s just wrong. The sail loads are related to the righting moment of the boat, not the sail area. The same heel angle with half the sail area, placed much lower down, puts at least 3 times the load on the clew. The reinforcements at the reefs should be bigger than at the clew, not smaller.
If the above mentioned sailmaker worries about horizontal loads when reefed, why not put in a few reinforcements along that line at each reef, perhaps together with a batten? While I’m at it, pressed rings for load bearing attachments like reefs? Insane! Use sewn on webbings or other methods to spread the loads to a much larger area. I used to race multihulls. We’d always tell the sailmaker: If there is one pressed ring in the sail, anywhere, you keep it. We got sick of ripping them out. Multihulls do give much higher loads on sails, though.
Making a sail well built takes work and cost. I understand why sailmakers try to avoid it, since “nobody will use the reefs much anyway”. I’ve noticed that the majority of sailmakers seem to have significant racing experience and little true ocean experience. Participants here may be somewhat the opposite? This gives us quite different reference points for what is “normal”, which we need to be aware of when ordering sails.
Thanks, Stein. Appreciate your thoughts, makes sense to me.