Com-Pac Yacht Owners Association

Com-Pac Model Specific Discussions => CP-16's => Topic started by: hinmo on September 06, 2014, 06:20:46 PM

Title: Main only
Post by: hinmo on September 06, 2014, 06:20:46 PM
it was gusting well over 20 kts today, so I sailed main only with the Admiral. Seemed to sail fine.

Does sailing main-only stress the rigging of a 1982 CP16?
Title: Re: Main only
Post by: Duckie on September 06, 2014, 09:15:21 PM
I sail main only almost every time I go out.  On one of my first times out with my 16 I tried it out because I had read that they won't sail very well on main alone.  I was going along well enough that I had to take a video of it to show off.  I have a furler on my boat which is wonderfully easy to use as a reef in strong wind.  I just got back a little while ago from fooling around with things I wanted to try, and one of them was furling the jib and pinching up with just the main.  According to my wind x, I was pointing just fine with only the main.  I  wasn't setting any speed records, but I was getting where I wanted to go.   

The last time I went out I ended up in a 35 mph gust that lasted for about 10 minutes.  That miserable furler jammed leaving me with a full press of sail up.  Boy was that fun.  If I  could have hauled in the jib that wind would have been no problem.  I ended up going forward and bundling the jib up on the forestay and carrying on with just the main.  There is a lot of sailboat traffic  in the Duluth harbor and a high percentage of them are running under either jib or main.  There must be something to it or they probably wouldn't do it.

My take on the rigging of the compac 16 is that it is plenty tough enough to stand up to just about anything.  The three stays which surround the mast are rock solid if they are in good shape and properly tightened.  After sailing for four years with home made standing rigging, the compac rigging is the last thing I would expect to fail.

I'm plenty green so take what I say for what it is worth.  But, so far I haven't seen any reason to not sail under main alone.

Al
Title: Re: Main only
Post by: JBC on September 06, 2014, 10:11:20 PM
I don't think sailing on main alone is an issue so far as upwind sailing is concerned (the 16 doesn't sail badly upwind with both sails up, but close hauled is not its strong suit in my opinion).  My only concern sailing on main alone is tacking in light winds.  Really haven't tried it, because I also have a furler and the jib is always out completely in light air.  And in heavy air, I reef the jib some but keep some headsail for better balance/tacking. 

Does the 16 tack as well on main alone?  Because the hull is fairly heavy for a 16' boat, I think gaining some momentum works well before tacking in light winds...I usually fall off some to gain a bit more momentum before tacking.

Any comments on tacking with main alone would be welcome.

Jett
Title: Re: Main only
Post by: Duckie on September 07, 2014, 07:04:14 AM
Yah, I have found that you need some momentum but it tacks real well in light air.  I would probably sail in light air with just the main only if I had broken something.  When I think about the difference between my compac and my weekender, it is night and day for coming about.  The weekender has a full length keel that resists spinning in its own length, while the compac only has a stub keel so it wheels around very easily.  Once they are both moving, there isn't much difference coming through the eye of the wind. I only need to keep a firmer hand on the tiller of the weekender.

I am having the opposite problem.  I found that in a blow the boat doesn't seem to want to go through the eye of the wind and I end up letting the jib shove me through.  I don't like doing this because when I have to haul the jib tight, it gets pretty busy and I sometimes go too far and have to recover from that. 

Al
Title: Re: Main only
Post by: hinmo on September 07, 2014, 07:20:50 AM
Thanks folks - you touched upon two other topics I need to explore:

1) jib furler
2) pointing

I want/need to add a furler this off season, being 250lbs+, its tough to get up to the bow on a regular basis. I will check with a local rigger and probably get a FF! by CDI.

Pointing. I can barely make any progress to wind with the main only. If I am real careful I can slowly gain ground on each tack, but it is an effort. I assume with the jib up I can do a little better.

I need momentum to tack well. I do have a foil rudder that helps.

Overall - love this little boat!

Title: Re: Main only
Post by: JTMeissner on September 07, 2014, 02:29:54 PM
As Al says, I too believe the rigging of the CP-16 will have no issue with the single sail (main or jib/genoa) as the stays are likely plenty strong, if in good shape, for the loads imposed by the winds.  And while I have sailed with just the main (due to high winds), I think there is a negative trade-off compared to flying two sails.

So, an overvalued two cents to follow: understand that I have one of the "stock-est" CP-16s around as it is from January 75 (though I am making small updates with rails and stanchions, perhaps a foil rudder, and I have a 155% genoa, etc.).  In stock form, with a 110 jib and main, a relatively common complaint with the base model was weather helm.  A fix to this was to add a bowsprit, effectively moving the center of effort (CE) of the sails forward and reducing the weather helm.  Another fix is to add a foiled rudder (it changes the underwater shape and therefore center of lateral resistance (CLR)/stalling of the fluid flow and much other physicsy/sciency stuff).  Weight distribution, mast rake, and amount of heel will also affect this.

The CE/CLR relationship changes vastly for points of sail, heel, wind speeds, direction, etc., and I won't get into all the math (FWIW this Wikipedia article covers it well for one sail:http://en.wikipedia.org/wiki/Forces_on_sails (http://en.wikipedia.org/wiki/Forces_on_sails)).  An interesting note at the very end of that article is, "The cumulative effect of several sails on a boat can be positive or negative. It is well known that for the same total surface sail, two sails properly set are more effective than a single sail set correctly. Two sails can increase the sailing thrust 20% compared a single sail of same area."

In a high wind environment our concern may not be with the thrust effects as we are overpowered for the conditions. We can reduce sail area by taking down a sail, reefing the main, or furling the jib, each with a different effect on sailing balance.  In light winds, there is a not quite opposite concern as the reduction in forces on all the stuff can be easier to overcome without danger to the crew or vessel.

For me: in light winds I find the jib and main combo to work best.  I also like to fly the 155% genoa in really light winds.  However, Keith Scott explains that the additional drag of the genoa may not be best in super-light conditions (http://www.ipass.net/sailboat/sweet16.htm (http://www.ipass.net/sailboat/sweet16.htm)).  The advantage to the second sail is the slotting of the wind flow over the main, changing the apparent wind, and it should allow for pointing higher.  The boat will sail with just the main, but by adding to the apparent wind, we get more power out of the prime-mover sail.  Tacking also becomes easier as the front sail will change direction first.  In light winds, you can allow the jib to backwind to really toss the bow around before releasing it and hauling it back in.

As discussed though, we do have a certain amount of momentum to help us through the tack, thanks to the keel.  I also have a Barnett 1400 and often rent a Hobie Bravo on vacation, each with just a main (considered cat-rigged, but the mast is further aft than most "cat-rigged" boats). These lightweight boats have a hard time tacking as coming into the winds really stalls them out.  I have to fall off to gain some speed before attempting to tack across a light wind. In really light wind, I may have to jibe all the way around to change direction.

In heavier winds, one can make progress with just the main, but you note the inability to point as well.  I'd make the trade of reefing the main and keeping the jib up.  This reduces the amount of sail to lessen being overpowered, but should keep the balance of the CE/CLR easier to attain.  You get the advantage of the slotting/pointing effects while staying in control.  With a furling jib, you have much greater control over this than I do.  Al also notes that tacking into a strong wind can have difficulties due to the windage of the boat stopping the tack.  Always a trade-off.

There is a certain feel to the boat when you have all the forces in balance, a sweet spot you can usually just sense.  Experienced sailors find this point much better than I do, but you really know when you hit it (my Barnett actually starts to hum).  But, crew comfort, cruising vs. racing, etc. all need to be considered.  Too much wind or too little, eventually one can consider their alternate means of propulsion (though sailing without such will force you to become a better sailor).

Our cat-rigged friends on the forum make take issue with a recommendation of keeping two sails up, but their boats are designed differently with a different mast position and sail shape.  Capt. Nemo didn't put a bowsprit and foresail on Frisky for nothing... :-)

So, after risk of tl;dr, I'm pretty sure the rigging is fine for one sail as two sails will produce more forces.  But I'm also convinced that for the CP-16, sailing with two sails will make certain things easier as the "balance" of the boat is better.  However, the second sail does add complexity (at least three more lines) which should be considered in varying wind conditions.

-Justin
Title: Re: Main only
Post by: capt_nemo on September 07, 2014, 07:47:13 PM
Guys,

I basically agree with Justin regarding the benefit(s) of having two sails up. My first response to building wind and waves in both my Island Packet 35 and Bayfield 32 was to tie a reef in the main and leave the jibs all the way out. Lowers the Total sail area CE yet still provides slot effect (enhanced main'sl performance), and the DRIVE that only a headsail can.

And, he got it right with his comment that I didn't go thru the time and effort to add a bowsprit and various headsails to Sun Cat "Frisky" for nothing. In addition to flying headsails for increased light air performance (the objective that got me started), I also have a working jib to use in moderate winds and also with REEFED MAIN in heavier winds to maintain the slot effect and provide the DRIVE needed to punch through a steep chop. Without the jib, the mainsail, even when full, didn't provide the necessary DRIVE to consistently tack effectively and/or punch thru a steep chop.

(http://i1125.photobucket.com/albums/l594/CPYOA/Sun%20Cat%20Headsails/friskyjib51.jpg) (http://s1125.photobucket.com/user/CPYOA/media/Sun%20Cat%20Headsails/friskyjib51.jpg.html)

My unorthodox recommendation for this posting is to try sailing with jib ALONE in moderate to heavy air. Different boats react differently to jib-only sailing and the only way to find out how your boat handles is to try it out. I was pleasantly surprised at how well my Island Packet 35 sailed in heavy air with ONLY the 130 % Genoa fully deployed and NO mainsail! No lee helm to speak of and no other disadvantages if I remember correctly.

Ain't it fun, just mess'in about in boats!

capt_nemo
Title: Re: Main only
Post by: hinmo on September 07, 2014, 08:56:08 PM
I used to sail my Catalina 34 with the 135 gennie only....Buzzards Bay is always pumpin 17kts and up, so being the lazy sailor I am, the furled jib was much easier to handle.
Title: Re: Main only
Post by: jb on September 08, 2014, 06:19:38 AM
my sailing options, especially when the wind kicks up, were greatly enhanced with this past, winter's addition of the CDI furler, a 2nd reef, and foiled rudder for my 96-16...for that extra convenience the Mast Gate and Tiller Tamer were also installed. 

hinmo, I'm with you, I got sick of bouncing around trying to drop the jib in rough seas (Nantucket Sound)..go for that furler!

j
Title: Re: Main only
Post by: Duckie on September 08, 2014, 08:18:27 AM
My compac has two head stays.  I have one that is basically the furler, and another that is set just back of the furler to mount a hanked on jib.  I was told by the PO that my furler is only to be used all the way in or all the way out, so there is no variability for the jib set.   In the event of sustained wind that is too much for the genoa, I can mount the second head stay and hank on a storm or working jib in its place.  I haven't done that yet because it sounds like a lot of monkeying around with no one at the helm and the wind blowing.  I've only gotten the compac to heave to once and it wasn't satisfactory, so I don't care to spend a ton of time on the fore deck until I have perfected that. 

And yeah,  I have seen that most of the big boats that are cruising up and down the harbor under one sail are using the head sail alone.  In the harbor if you are trying to go somewhere, you are generally on a broad or beam reach.  Next time it is blowing a bit I am going to have to try that.

Al
Title: Re: Main only
Post by: JBC on September 08, 2014, 11:44:55 AM
Lots of knowledge, experience and good advice in this thread.  If there's one clear signal that comes through about using sails and their effects, it's to try them out! 

I too have heard (and read) over and over that a jib/genoa on a CDI furler is to be used only when all the way unfurled or furled...in other words, not partially furled.  Tried out that for myself and have been surprised (at least on my 16III with a 110% furling jib), that a partially furled jib works wonderfully.  In heavier winds, I can tie in a reef in the main and partially furl the jib, and sail all day as though this was meant to be.  But I do plan to sail some on the main alone (and then jib alone) just to see how that works in all of the conditions I usually encounter.

BTW, I've been working on heaving to and have found my boat does this pretty well in 8-10 mph winds.  Have to adjust the tiller a bit once in a while, but works well enough.  But in gusts the boat either wants to push away quickly from the wind or start sailing upwind...depending on the source of the gust...even with the jib backed!  In any case, my wife and I can enjoy a quick picnic on the boat while heaved to, at least for a while.

Always something more to learn.

Jett
Title: Re: Main only
Post by: wes on September 08, 2014, 07:04:11 PM
JBC - when hove to, try leaving the tiller pushed all the way hard over (I keep a little bungee ready to hold the tiller against the stern rail or cleat) and instead use the mainsheet for adjusting your orientation to the wind. You should be able to find a stable sweet spot where gusts won't affect you. Works very well on the 19 and ought to work on the 16 as well.

Wes
Title: Re: Main only
Post by: Bob23 on September 08, 2014, 07:23:03 PM
JB:
  When I had my new sails built for my 1985 23/2, my sailmaker suggested a luff pad for the headsail, stating it would enable me to furl it part way and still maintain a somewhat proper shape. It seems to work although I do admit to not knowing everything about sailing or sail shape. He's a very reputable sailmaker so I went with his suggestion.
Bob23
Title: Re: Main only
Post by: jb on September 08, 2014, 08:51:31 PM
re my CDI furler, have had 'MANY'  sails with my past two boats with a partially furled sail and have been very satisfied with both the performance and flexibility that you get with the rig.

I suppose if you are in some type on competitive sailing, that perfect shape makes a difference, but for every day use I'll take the flexibility that allows someone to adjust  to various seas and wind in comfort.

re sailing with jib only, I find the C16 sails surprisingly well!

The ability to furl the jib and the 2nd reef in the main is now my " GOTO " combination anytime the wind gets close to  the 15 knot area.

j
Title: Re: Main only
Post by: Bob23 on September 09, 2014, 03:58:11 AM
   Although I have 2 reef points in my main, I havn't used the 2nd yet. The first goes in when wind reaches 15 to 18. Just seems to balance the boat well, makes for a more comfortable and faster sail. And I don't notice any wierd shape to my genoa when I furl it a few turns. Oddly enough, and I know this doesn't make sense, if I've got a full main up in too much wind, furling the headsail a couple of turns seems to ease the weather helm a bit. I don't actually know why but it is what it is.
   But back to the thread, I don't know about the 16's, but my 23 won't hardly get out of her own way with just the main up. She needs the headsail. I have had great downwind runs with just the headsail up. If fact, in high winds going downwind, I think it's a lot safer, too. Don't ask me how I know this.
Bob23
Title: Re: Main only
Post by: Duckie on September 09, 2014, 06:54:46 AM
Hey this is great.  I've been asking around about that all in or all out deal for a while and now I have an answer.  Next time I go out I'm going to try it. 

Here's something I have been messing around with, try sailing backwards.  A lot of the time I will motor off the dock and head up into wind when I have cleared all the obstructions to raise the sails.  Last time I did this I raised the main and slabbed it hard with the  sheet dead into the wind to see if it would weather vane.  I also tied the tiller in neutral  so that when I started going backwards it wouldn't turn me across the wind.  I found that the boat would weather vane within a fairly narrow slot.  If I got cross wise to the wind a little bit the main would power up and turn me back into the wind. It wouldn't go too far because it was hard amid ship so it would luff pretty quickly.  This isn't exactly heaving to, but it worked long enough for me to unfurl the jib and cleat it off.  When I was ready to go, I let the rudder loose and pointed the tiller at the direction I wanted to go.  When the sails started to fill I set them and took off.  I think this would work best with someone manning the tiller to steer the boat while it is going backwards, but I sail alone so tying off is the next best thing. 

Al
Title: Re: Main only
Post by: capt_nemo on September 09, 2014, 06:58:53 PM
Duckie,

With this group, if you don't get a satisfactory answer to your question right away keep asking!

Someone with the requisite knowledge and/or experience will eventually chime in.

capt_nemo
Title: Re: Main only
Post by: hinmo on September 09, 2014, 09:07:15 PM
Well, you've all lost me by now, but thanks anyway!

I will be installing a furler for next year....CDI FF1 or other. I have a bowsprit option on a std CP16 (fractional rig w/o forestay extended to bowsprit).

Hoping I can do this cheap working with local sailmaker to cut and add luff tape to one of my oversized jennys.

...to be continued?

Thanks all
Title: Re: Main only
Post by: Salty19 on September 10, 2014, 12:45:46 PM
I never sail on the main only.  Pointing is compromised too much as is speed.
Even in strong winds, I'll reef the main and furl the jib to a hanky size (Ok a little bigger than that!) and be comfortable and safe.

the exception is medium to strong winds and running downwind. I will occasionally furl the jib all the way sailing downwind when I'm feeling lazy so I don't have to worry about a whisker pole or keeping the jib filled with air.