4-sided sails on Raid sailboat

[AntsUiga]

Who knows how to setup and trim 4 sided sails for speed, efficiency, pointing ability?

Clint Chase Deer Isle Koster (KDI is preferred over DIK).
14 feet, about 250 pounds with gear, and about 100sf sail area. CNC kit with some early design details that were changed such as kick up control of rudder.

The KDI gets picked up next week and goes immediately to Pocket Yachters Palooza in Port Townsend. The three day cruise that follows is tentative, unknown sailboat, never sailed in area, and not sure about sleeping on board, also tweaked my back while changing brake rotors on truck.

But , other day sails on way back are under consideration, such as Humboldt Lagoon(s) and maybe coastal rivers to inland.

Ants

 

[AlanH]

I "watched" the development of the Deer Isle Koster on the Wooden Boat forum, it's a gorgeous boat and a wonderful camp-cruiser.

About balanced lug sail trim...low stretch halyards are your friend. If the downhaul on the front of the boom is not 2:1 already, make it so. 3:1 ....mmmmm. Maybe. 4:1 is probably too much. However, you want that leading edge nice 'n tight. The most common balanced lugsail oopsie looks like this.



See the big crease from the back of the boom up forward to the front of the yard? If you get that, try two things...1.) easing off on the boom downhaul and then topping up the yard harder and then...2.) tightening down on the boom downhaul.

you have a little bit of this going on already in the photo you posted. You can also try making a change so the boom rides an inch or two further forward, relative to the mast.

Wonderful boat!

 

[AlanH]

I'm still hoping that an SSS "raid" - small boat cruise is in the works for someday. It would be fun to see your Koster out with RoG

 

[AntsUiga]

Any interest for the next SSS Raid is always good!

I have one on the calendar with TSCA on Tomales Bay in September.

I have been searching for useful ways to improve sail trim. The search has not yielded an overabundance of good information. In general, the sail attachments are not fixed, or are open to many variables. The sail is fixed on the tack of the boom, but the location of the boom relative to the mast can move up or down, forward or aft. Simple - Yes, but subject to lots of options.

On this boat, there is a fixed fairlead and hook on the yard with a ring to hold yard close to the mast. As for your suggesting to move the yard side of sail, there is a limit (1-3 inches) by adjusting the lashing. If that does not work, the attached fairlead get screwed to another location.

Ants

 

[Tom P.]

Ants,
Alan suggested: “You can also try making a change so the boom rides an inch or two further forward, relative to the mast.” Wouldn’t moving the yard aft do the same?

It looks like the eye plate on the yard was moved aft at some time. Which moved the yard forward. If it went back to the original position would that help? Maybe the attachment point on the yard needs to be adjustable? Or you could try using a lashing temporarily to find the right attachment point.

 

[AntsUiga]

Both excellent suggestion from Alan and Tom.

My concerns are based on a set of photos without seeing the boat in person. It would be nice to have a general plan when I can move and adjust things.

Step 1 would be to unlash sail from everything, support it on 4 corners and see what shape gravity gives the sail. How full is the luff? What happens when tension is applied to each corner? All this confirm how well the sailmaker did their craft.

Step 2 may be to add yard and boom and see how that impacts horizontal sail shape.

Step 3 would be to use lashings to move checkout to mast. Then the fore and aft attachment point to yard and boom can get scrutiny.

Step 4 would to take best lashing points and go sailing.

Then, the set of reef points need to be tested.

When all seems good, time to go with permanent attachments instead of lashings. There is an abundance of loose blocks, cleats, and multi-part purchases to play with.

If the hard on the wind performance still seems to suffer, a jib on a furler is an option that should help.

Just because it is an option, there is also a spinnaker cut to Sabot dinghy size to play with.

Ants

 

[AlanH]

This picture is of a skerry in France...it's not my old skerry, but I rigged the downhaul the same way as 3:1 with smaller blocks... except that the lower block on my setup was affixed to the mast, not to the deck. That way I wasn't going to pull up the deck when I torqued down on that downhaul....all the compression was taken by the spar.



You won't beat a Laser or a Banshee to windward in your Koster with a balanced lugsail, so do not despair if more high-tech dinghies point higher. Where that boat will shine is from about ten degrees off of hard-on-the-wind down to a very broad reach. That goes double for when you have 70 pounds of camping gear aboard.

 

[AlanH]

Look closely at the sail attachment on your boat. It's loose-footed on the boom. I would suggest having a loop of line that keeps the clew close to the boom, but is loose enough that it will slide back and forth easily.Then put a 2:1 or 3:1 purchase on the outhaul, leading up to a cleat somewhere over the daggerboard.

The upper edge of the sail is laced to the yard. I'm going to STRONGLY recommend that you lace the sail like this:



rather than the "wrapped around the yard" style, which is how it's done in that picture.

IN fact, Michael Storers page about rigging lugsails is a very good read, check it out.

https://www.storerboatplans.com/tuning/lug-rig-setup/everything-lug-rig-and-lug-sail/

 

[AntsUiga]

Thanks! These tips on details are very useful.

Keep the SSS Raid enthusiasm building!!

Ants

 

[Tom P.]

Happy day! Look at that smile.

 

[AlanH]

Happy day! Look at that smile.
View attachment 6698

Ohhhh! Nice! Where did you find her? Did you have to drive across the country to get her?

 

[AntsUiga]

The DKI was found for sale in a notice for the group email for the Salish 100 (small boat sail from Tacoma to Port Townsend). I thought about the purchase overnight and sent a deposit the next day. The pickup point next to SeaTac airport in WA, just two days ago.
I enjoy a road trip.
Yesterday was spent tweaking sail setup with the help of Dan Newland. Today, the boat is on display at the Pocket Yachters Palooza at NWMC.

The sail looking better. The yard attachment point was moved aft about 12-inches and puts the hoist point at about 40% of the yard length. The temporary lashing is used until it seems right, then the padeye moves.

Fun and cool in PNW.
Ants

 

[AlanH]

The DKI was found for sale in a notice for the group email for the Salish 100 (small boat sail from Tacoma to Port Townsend). I thought about the purchase overnight and sent a deposit the next day. The pickup point next to SeaTac airport in WA, just two days ago.
I enjoy a road trip.
Yesterday was spent tweaking sail setup with the help of Dan Newland. Today, the boat is on display at the Pocket Yachters Palooza at NWMC.

The sail looking better. The yard attachment point was moved aft about 12-inches and puts the hoist point at about 40% of the yard length. The temporary lashing is used until it seems right, then the padeye moves.

Fun and cool in PNW.
Ants
View attachment 6699

View attachment 6700

Using lashings is great. It allows you to move things around, as you see. While it's very unlikely that you will move the sail enough to induce too much lee or weather helm, if you DO happen to get that result....just move the lashings!

Pretty boat...just a really lovely boat. I didn't know that one had been made in the PNW!

 

[Tchoupitoulas]

Congrats! Looks great.

 

[AntsUiga]

She floats (finally)



She sails (but the vertical seam, flat cut sail is nothing to get excited about).


Saling photo courtesy of ‘Thorne’ on the humboldt lagoon.

 

[AlanH]

You might have overdone it a bit on the halyard tension in that photo. Ease off half an inch. When it's blowing 15+ you'll want it that tight. The Humboldt messabout is on my "someday" list!

 

[AntsUiga]

Good eye - you are right. The sail controls are not up to snuff yet. The downhaul was borrowed from the Moore 24. It does not release easily, so I was in the lazy mode. The setting was ok for the beat to the upwind corner of the lagoon.

The rigging is being changes with each outing.

The best spot to sit during light airs is where the main sheet is attached to centerboard trunk. The main sheet will be moved and a thwart added. Details, details.

Those lagoons are a delightful place to sail (and camp).

Ants

 

[Tom P.]

My experience with boats “new to me” has been first to just try what’s there for a while without making changes. I often learn something. But then, I’ve also said it takes a few years to get everything just how I want it.

Love the picture and your adventure.

 

[MAGICdreamer]

Hi, Ants:
I was recently clued into your posting here by Sleddog and finally got around to checking it out. Lovely craft and Stone and Big Lagoons are indeed a treat! I second Alan's recommendations for getting the best out of your "flat, 4-sided sail". ;-)

The slings we use on our Sooty Tern, WEE BONNIE, for the yard halyard, boom downhaul and mainsheet attachments are loops of dyneema. These are light, strong and can be shifted without too much travail. Good downhaul tension and an easily adjusted outhaul on the boom facilitate tweaking all of those delightful strings. (You would not want to become bored, would ya?) Our downhaul is multi-part (I forget how many) but it is laying on deck in the second photo. On a breezy day, we need all of them parts to keep the luff taut.

I am looking forward to seeing the boat when you come this way.

cheers,

Craig

 

[AntsUiga]

Thanks to Tom and Craig for the additional comments.

My impression is that the prior two owners did not have the boat dialed in. One significant challenge is the skipper’s weight (200 pounds) and the weight of the boat when ready to sail (250 pounds). Additional ballast of 30-40 pounds was added next to centerboard - not sure why. For boat trim, the skipper needs to be within a foot of centerline, but as the wind increases, moving outboard to rail is useful. A tiller extension does a good job of keeping the tiller inhand, but the sail controls are not as user friendly. The space needs to be increased from main sheet from about 1 foot to 3 feet.

The sail controls do not operate smoothly while sailing. The 2:1 outhaul works while setting up, but is overloaded while sailing. Better blocks and more purchase and cleat placement are pending. A 3:1 downhaul was added, but the leads did not extend back far enough and line was old and did not run smoothly. The main sheet needs to run smoothly also.

The goal is to have all sail controls easy to operate from any location (so I can tweak them to my heart’s delight).

The mast partner did not follow the design. A light encounter with some overhead branches showed the construction deficiency. While the setup was quick to use, the lack of strength was shocking. The design used brass straps to spread the load and will be used.

Two photos of mast partner damage and reconstruction with additional support added to deck. Reconstruction is not finished yet.

But, it is all fun!