Too much weather helm

[jsgonz]

My 1985 28.5 Hunter sails nicely but at 15kts+, I develop too much weather helm. I have a new main, and a 125 genoa. The mast has a prebend that rakes the mast aft. At 15kts heeling 20 degrees, my lines are slack on the lee side and I have the wheel turned at least at the 3 or 9 oclock position to counter the boat's tendency to round up. I do like to carry full sail when I can but at 15 knots, the boat should sail more balanced. I wonder whether I need to tune my rigging better. Should I tighten the forestay and loosen the back stays? Or depower by reefing at 15kts.

Any suggestions?

 

[Jackdaw]

95% of all fractional boats will round up in a breeze. De-power.

1) Flatten your sail plan.
2) Blade off your main.
3) Twist off your sails
4) Reef.


In that order.

 

[Nom De Guerre]

Possibly both, you may have too much pre-bend, and a big roachy full battened main.

The pre-bend tuning is covered in the manual, the reefing of a big main with a small foresail is something you should try for balance, and I recommend it at 15 knots on this boat.

Btw, it's masthead rigged, not fractional.

 

[markwbird]

I know how you feel

I had the 25.5 and currently own a 34. all very similar to the 28.5. They get overpowered and round up easily. Try moving the traveler up higher and easing the sheets to let the boom back down to centerline. This opens the leach and spills air off the main depowering it. Also, tighten the outhaul. To depower the headsail move the jib cars back. That will reduce heel as well. If you are still overpowered then reef. These boats have big sail area so reefing is necessary when the wind picks up. It's mainly about depowering the main. That's the sail that causes the roundups.

 

[jsgonz]

All good responses. However, my mainsail has a short foot and therefore not as large sail area as the orignal and not a large roach. I did try to flatten the sails by bring back the fairlead for the genny and tightening the outhaul for the main and vang. The sails looked very flat. I like the idea of opening up the top of the main with the traveler to windward and letting out the mainsheet. But I think I have a tunning problem that would override the sail triming.

The diamond inter-shrouds should bring the mast more upright but would this help bring the center of effort forward and will this help weather helm?

I have had her for 3 years and it will round up before allowing the rails in the water which is good and I understand a safety design, but even on a broad reach this past Saturday when it was blowing 15+ maybe hitting 20 at time, was very exhilerating but disappointing at times with it wanting to round up from that point of sail which would bring the boat almost 100 degrees which is a hugh turn back toward the wind. My thought is that I should have been having less weather helm at this point of sail that a close haul. I was flying however never getting under 6.5Kts.

I thought with a large head sail and modest main, I should better balanced.

I hate to think of trying to tune the inter-shrouds as I really don't think even the outer shrouds are where they should be. As I mentioned, at 20 degrees heel, I had my leeward shrouds very loose. ( BTW i just got it out of the yard with a new bottom and waxed hull and she is never been in such good shape. You can see pictures of her when I splashed the first time in the boat info section for the 28.5 on this site.)

I will mentioned also, my one year old auto helm was having to work hard but could not handle the the broad reach point of sail but could close hauled.

 

[RichH]

If your 28.5 is the shoal draft version, what you could probably be experiencing is not weather helm but a 'skid' off to leeward.

How to tell if a boat is skidding (even if the boat is a standard depth keel version): When this 'weather helm' develops, immediately look at the stern wake and the turbulence that the rudder is making. If that turbulence wake is not coming almost straight back off the stern but is at a noticeable angle diverging from the boat's centerline its probably a skid and not 'weather helm'. A skid 'feels like' weather helm because he boat is essentially also moving 'sideways' and those side forces are acting on the side of the rudder.

A skid to leeward is caused principally by two possibilities:
1. excessive heel that reduces the effective 'lateral resistance'.
Rx: Reef earlier to keep the boat as vertical as possible and to reduce heeling.

2. Loose forestay (insufficient backstay) tension .... if you look at the sagging curve of the forestay when windloaded by the jib, you'll see a much larger 'curve' in the forestay when the boat is skidding than when the boat is not skidding.
Rx: Increase backstay tension + use LESS jib sheet tension. To 'match' the sag in the forestay to the curved shape cut along the luff of the jib by correct backstay tension: http://www.ftp.tognews.com/GoogleFiles/Matching Luff Hollow.pdf

Other ... suggest increasing the mainsail halyard tension as a 'test' during the wind/wave conditions where this apparent weather helm begins to occur. If increasing the halyard tension reduces 'weather helm', then its 'really' weather helm caused by the boat's immersed geometry/shape etc. when its over on a heel; if there is no or little difference in weather helm when the halyard tension is increased, then the boat is probably 'skidding' off to leeward. Look at how the wake is coming off the boat at its stern - straight or at a noticeable angle?!!
Suggest you also read the following in case your DACRON mainsail is incorrectly raised as this can seriously affect 'weather helm' and including uncontrolled 'rounding up' potentials: http://forums.sbo.sailboatowners.com/showthread.php?t=120970 see post #1

;-)

 

[David in Sandusky]

More thoughts

I agree about flattening your main first, then reefing. Other ideas include:

- Increasing your headsail size above about 100% increases weather helm, because the sail area is added aft of your center of balance. So a smaller headsail will reduce weather helm. Further, carrying a larger genny definitely increases heel, making your rudder less effective as described below.
- When we replaced the old, blown out mainsail that came with our '77 h27, we saw a 5% reduction in heeling, and a 1 kt increase in speed in the same close reach condition in 15 kts of wind.
- Because of the braking effect of excessive rudder to counter weather helm, and reduction of effective sail area at 20 degree heel, reefing can increase boat speed in winds over 15 kts by putting the boat back on her feet, and reducing rudder braking.
- As heel increases, your rudder becomes less effective, with more of its force going to lift your stern, rather than pushing it upwind to counter the weather helm. At 20 degrees, a gust increases heel and weather helm, you increase
rudder angle even more, and the rudder finally stalls, causing a round-up.

 

[Warren Milberg]

Having sailed a H28.5 for over 11 years on the Chesapeake in all kinds of wind conditions, I feel pretty sure that your boat is rounding up due to too much headsail up or a baggy, blown out main, or both. You'll see a big difference in performance by reefing the main (first) and/or reducing headsail sail area, or both.

 

[jsgonz]

Hi Warren. What happened to the 28.5 website? Oh well it almost gone, no forum.

Thanks for your thoughts. My main is new and less sail area than what the boat calls for. The head sail might be a bit baggy but still many years left in her. I have been told my by harbor mates that the rake is too much and that I need to tune down the mast. I'm relunctant to just loosen the interstays that rakes the mast. I am afraid that if I let too much out, I will not be able to bring it back where it was.

Answering RichH, I have the deep draft, 5'2" version, and yes, I can kick up a rooster tail almost from the rudder on a heel and it is coming out of the windward side from stern. Surely slowing me down.

This weekend, I think I will tighten my forestay as it has a bit of a mid-bend while at rest, and try a bit less head sail. Flatten the main more. I have the main halyard as tight as I dare at this point.

Thanks for all the suggestions and will report back.

 

[jsgonz]

RIchH, great article on your previous post and the link to the head sail tension. I will study this closer and give your suggestions a try. Again, I will report back to you guys after I study the suggestions and made some adjustments on my boat's rigging.

 

[RichH]

jsgonz --- do especially review that article on properly raising a dacron main: http://forums.sbo.sailboatowners.com...d.php?t=120970 see post #1 this is 95% easiest way to control or lessen 'true' weather helm problems.

The following is quite advanced and relates to the SHAPING of the mainsail, so I apologize if it makes one 'glassy eyed':

'Tensioning the luff on a boltroped dacron mainsail via the halyard will do two things simultaneously -
1. It will move forward the point at which the maximum draft occurs - reduces weather helm

2. It will cause the leech to 'open' or become more 'flatish' and with less tendency to hook-up-to-weather.

The combo of both above will result in 'faster' boat speed (in relatively flat water) with most of the 'roundness' closer to the luff ... the faster the boat the more important this SHAPE will be and the sail will be more stable (luffing) and be able to tolerate wider angles of attack (for less precision/accuracy needed by the helmsman) at the 'higher boat speeds' (eg. - when surfing or planing or getting up to near 'hull speed').

When beating, watching the mainsail's aft end of the leech to be mostly parallel to the boats centerline is quite important and also gives a visual indication of correct or optimum mainsheet tension .... if you put in too much mainsheet pressure the leech will begin to hook up to weather and the boat will increase its amount of heel.
When beating especially, If the aft end of the leech (especially at near the area of the second-from-the-top batten) is not aligned mostly parallel with the centerline of the boat and is 'pointing towards windward' .... youll get more weather helm (slower boat speed), plus increased heeling (for more weather helm PLUS increased skidding). Control the 'attitude' of the that #2 batten via mainsheet tension. Conversely, with insufficient mainsheet tension and the aft end of #2 batten is now pointing towards leeward, youll be 'falling off' the beat (faster but not pointing very well).
Suggest you aim to control the 'attitude' of that #2 batten with mainsheet tension (and vang tension), but only AFTER the luff has proper TENSION from the halyard which gives you 'basic' weather helm control/adjustment for 'todays' wind and wave states.
Additionally, over-tensioning the mainsheet to purposely 'hook up the leech' will allow 'power-pinching' (high lift at an increased angle of attack during slower speeds - like putting down the wing flaps on an airplane.) The penalty when power-pinching is a 'tremendous' amount of heeling and increased skidding.

Its all too easy to apply too much tension to both the jib sheets and the mainsheet and totally distort the 3D sail shape .... which usually results in increased weather helm, skidding, and increased heeling. This is why racers prefer non-stretchy laminate sails and backstay tensioners. I still prefer dacron because its sooooo easy to adjust the SHAPE while underway.

hope this helps ;-)

 

[H30Gary]

JS - Do you have telltales on the leech of your mainsail? These help a lot in determining the correct interplay between mainsheet, traveller and boom vang. Ideally, you want all of the leech telltales flowing straight back as though they were an extension of the sail itself. You achieve this by adjusting the relative tension of the mainsheet and vang. Starting with the traveller on center and the mainsheet sheeted in so the sail is not luffing, look at the leech telltales. If the top telltales stall (hang straight down or blow forward) while the lower telltales flow straight back, ease the vang (and maybe tighten the mainsheet) to get more twist in the sail. Conversely, if the lower telltales stall while the upper telltales flow correctly, tighten the vang and maybe sheet out to get less twist. Once you have the right twist established, if you are overpowered and/or have excessive weather helm, drop the traveller down. That should cause the mainsail to luff some, reducing power and reducing weather helm.

If you can't control the weather helm by sail trim, then I would suggest you rake the mast forward more. That should help.

 

[Warren Milberg]

jsgonz:
I, too, miss the old H28.5 website. When Steve P. sold his boat, the new owner also agreed to take over the website. He soon got in over his head with the php format and cms and just let the site deteriorate. I suggested to him that he move the site to one of the SBO/HBO sites here as Phil Herring had agreed to that many years ago. Nothing happened. Very sad.

Back to your issue with heading up. While tuning the B&R rig is always a good idea, you may want to consider having a professional rigging shop do the job. Typically cost is $150. Yet I do not think a poorly tuned rig is the issue. Most of these boats already have a lot of mast pre-bend in any event. I think you'll find the boat will head up much less with a reefed main and partially furled headsail. Since I sailed alone a lot, it was hard for me to reef the main when underway so I usually just took the easy way out when the wind really piped up: I just hauled in the headsail quite a bit. My boat, with a 150 genoa, also had a foam luff so I could roll up a lot of that sail and still get great performance. The old rule of thumb about only rolling up a headsail 30 per cent is just not true with this boat. I could roll up the headsail to spitfire jib size and still do hull speed if the wind was high enough. A full main and a 125 genoa is just too much sail for these boats when the wind is over 15kts. In such conditions, you'll be fighting the helm and going more sideways than forward. Experiment with rolling up the headsail to various positions and see what happens.

 

[jsgonz]

Thank you Gary. I do have telltales on the leech of the Main and play around with the trim to try to get them streaming. I move my traveler from time to time but hardly ever work the vang. So I will be trying your and others suggestions. Understanding sail trim and its effects on the boat is still a mystery to me after 3 years of having her on the Ms Gulf Coast. Like Warren, I solo sail most of the time so I want to ease the strain on her and me when the wind pipes up so that I have more control and still clip along at a nice speed.

Warren, the 28.5 site was good while it lasted. It was a great resource when I had Mi Novia on the hard addressing deferred maintenance issues and needed replacements. You surely contributed mightedly toward its mission. Well done sailor!

 

[RichH]

Tell-tales .... go here: http://www.ftp.tognews.com/Publications/Arvel Gentry Articles/08_Checking_Trim_on_the_Wind.pdf