Thread: GIS handling characteristics

A cord similar to venetian blinds (VB cord) is OK if you go through the hole and the sail several times. Better still is the thin spectra, but the VB cord is OK, probably because the distance is so small.

In an emergency, or as part of a considered plan you can "strip the rope" with many yachting ropes.

If your rope is ever too thick then it is possible to strip it. Most yacht ropes have a double construction where there is a cover over the inside of the rope.

So you can remove the outside on some ropes and use the inside only. Attached pic below.

The problem can be that sometimes the inside is very loosely woven and tends to fall apart easily. In that case it is a bad idea. If you separate the inner and it has a reasonable form and you heat seal the ends it should be OK.

It works really well with spectra ropes which are set up so the outer is polyester and the inner is spectra. So most of the strength and almost all of the low stretch is with the inner part of the rope. So strip the outer and you have a thin spectra core that is light, strong and little stretch.

Spectra is particularly good for this even though it doesn't heat seal very well. sometimes a whipping with a light line around the end (use some stitches through the rope at the start) can be more effective). Brian might have some other ideas.

But the great things about spectra is it is very UV stable and very abrasion resistant, so stripping the outer and using the core works very well.

Some ropes are really bad to strip in this way. Vectran (another high strength fibre) has almost Zero UV resistance, same with polyproplene. But you almost never see polypropylene in a core.

Best wishes
Michael

Just let me explain an easy whipping method that includes sewing.

Spectra doesn't heat seal very well which can cause problems with ropes that have to be tied and untied a lot at the end. When you are doing a one time lashing that will stay tied then even the poor heat sealing at the end of a spectra rope is usually enough.

Cut a long length of whipping twine can be waxed or natural) and pull it through the needle. Pull both ends through so the needle is in the middle.

You start sewing up and down through the rope. The place to start is about 2 rope diameters from the end of the rope or where you are planning to cut ... if you have not cut the rope yet.

Tie a knot in the loose ends of the whipping twine about 50mm from the end

You put the needle through and pull the twine through until the knot hits the rope. Keep going up and down through the rope making 6 or so stitches on your way up to the cut (or to be cut end). Use a reasonable amount of tension.

When you get to the end you start taking the whipping twine around the end of rope and keep tidily winding around the rope (no stitches) back towards the first stitch until all the stitches are covered in a neat layer of whipping twine. USE LOTS OF TENSION.

Finally stop just beside the first stitch and put the needle through the rope again.

Cut off both ends so there is about 20mm of whipping twine excess.

Wet your index finger

Light the ends of the whipping twine with a match and they will burn with a little molten ball of polyester at the end. As the ball of burning sticky molten polyester gets to the surface of the rope you push it into the rope with your wet finger. This welds it to the rope so it can never come undone.

You can use this same method to put a loop in a rope as well - not a whipping in that case but a "seizing". it is fine for medium strength, but can be used for high strength when cow hitched around the attachment or fitting. Or for high strenght like a downhaul or a boom vang you can put it through the fitting you want to attach, then tie a single half hitch in the rope then start the seizing.

MIK

Ok, I invite all my balanced lug sail aficionados and friends to look at this album I put together.

Picasa Web Albums - CallSign222 - GIS Rigging

please feel free to leave comments, investigate, poke, do whatever. Please help me get the performance that I know lies within this wonderful boat of mine. She is a speed demon, I feel it in her, help me release her power from within!!! I want to go fast and "sail circles around character boats" and laugh as she flies from wave top to wave top. I built her for speed cruising the coast, please help let me do this!

I went ahead and released the foot from the boom.

The wrinkles disappeared, the sail filled. The boom definitely has some flex now, should I build a stiffer boom or is that ok loose footed? I think there's a fantastic discussion somewhere here on loose-footed boom construction, I could build one in a day, I'm thinking rectangular, two piece doug fir, 37x 52-60mm or so. Any ideas?

Still a little tight in the head.

There are something like 35 pictures for your perusal. Mostly close-hauled, a few downwind ones. I did the best I could with the winds and the sun.

Tell me, is this the solution? Are Duckworks sails to be loosefooted? Did we figure this out!?



MIK, thanks for the line advice, I've been wondering to all heck and back why I can't seal my lines closed. Thank you again.

Bobwes made a light hollow boom out of two light pieces of timber as the top and bottom edges and plywood sides.

But want to go through the great photoset.

Your corner lashings are not particularly tidy, but they do hold the sail both OUT and IN. When you get some lighter line you can redo.



This keeps on worrying me too. When the sail is laid out flat on the ground how much of a curve does the foot have? If it is cut straight it would explain a lot.

It also looks like the tabling (the ribbon of cloth folded around the edge of the sail and sewn to reinforce and seal) is too tight.

If the bottom edge of the sail does have some curve then try this below.

As an experiment tension up the foot more and put the lashing on again and hoist the sail and see what happens.



This pic makes it look like the bottom of the sail has been cut without any roach (convex curve) at all. Double check.

Also you can reduce some of the boom bend by tying the rear boom block through the clew of the sail. Move the traveller back one or two holes in the inwale to match.



It does look completely straight here. The loose footing has gotten rid of those wrinkles. Nice to see the rope looped under the boom too - good work. The outhaul is way to thick. I know you have to go and get some lighter rope - so it will do for now. Much better to use thinner rope and go backwards and forwards a few times. Venetian Blind cord would be fine if the corners of the sail are non adjustable.



It might be the camera lens distorting the pic but the luff should be more vertical like the drawing in the plan or my rigging page.




Seeing you have gone loose footed, ease the foot so that the sail in the middle has some depth. Maybe about 75mm belly in the middle of the boom. ie the lateral gap between the sail and the boom. If the wind is strong you will need to tighten it again or reef.

Hope that is some help.

MIK

Thank you for your analysis Mik. Looks like we're getting there.

Yes, this was a quick and dirty job lashing wise, waiting for the evening breeze and hoping to catch it before the sun set.

I do need thinner lashing at all corners, Duckworks only carries the 1/4" as the thinnest line, and I just haven't been able to get to the coast yet to get some 1/8" for the outhaul and lashings, that's coming when it comes. That will help get some tension too, since I'll be able to run it through the grommets several times.

The luff is usually vertical, the sail came up and down several times, and a few times the downhaul slipped aft on the boom and thus the out-of-kilter luff there-- my bad.

What rope is under the boom that you are glad of? I want to make sure to repeat that success.

I'll go check to see how straight the foot is. How do I check if the roach has been cut appropriately? And what do I do if it's not? Kind of stuck now, aren't I?

EDIT I just read your comment at the album about the foot not being tight enough and the boom not being bent with the foot still laced. That's as tight as I could feasibly get it, and that included a passerby/walker and we pulled away at it the best we could.

Mik,

Here's the sail when I pulled it out of the box last year. You can examine the foot.

P9280002.JPG (image)

Originally Posted by callsign222

Mik,

Here's the sail when I pulled it out of the box last year. You can examine the foot.

P9280002.JPG (image)

Sorry off topic but forget about the sail what abut the very cool sideboard.

Just lay the sail out on the ground and compare to the now straight boom. If the boom isn't straight, use a straight edge or a stringline to see the round on the foot.

I think that thinner rope and multipurchase will help you get a lot more tension if you want.

Note I gave two lots of contradictory advice there. before I saw the loose footed sail flying. the tabling wrinkles have mostly gone. And loose footed sails on the front of the boat should have some depth in the bottom of the sail.

It is good to have that depth in medium winds before the boat is overpowered and also in rough water upwind when the boat is overpowered (you keep the top of the sail flat with lots of downhaul and the depth at the bottom gives you power to beat the waves without too much heeling moment.

I say the front sail because normally if there is a jib or a foresail then the foot of the second sail back has to be flatter.


MIK

Originally Posted by m2c1Iw

Sorry off topic but forget about the sail what abut the very cool sideboard.

I am but a poor airline pilot, the sideboard is my mother-in-law's. We live in a basement room underneath the kitchen. I can pass along the compliment!

(To the international crowd-- this is how two thirty-somethings get along financially without going into deep debt in the US. It's not for lack of education, oodles of experience, or highly professional and skilled jobs either... I'm barely staying in the black-- most of my co-workers are carrying up to 100K in debt-- not including their mortgages!)

EDIT Sorry guys about the whining blog/divergence from the thread, I was paying bills this afternoon... you know how it goes, and feeling sorry for myself at the dwindling numbers. I am very lucky and thankful that I worked hard to stay out of debt and that my parents-in-law are helping us out too. I could be in a whole lot more trouble with no boat!

Originally Posted by callsign222

I am but a poor airline pilot, the sideboard is my mother-in-law's. We live in a basement room underneath the kitchen. I can pass along the compliment!

(To the international crowd-- this is how two thirty-somethings get along financially without going into deep debt in the US. It's not for lack of education, oodles of experience, or highly professional and skilled jobs either... I'm barely staying in the black-- most of my co-workers are carrying up to 100K in debt-- not including their mortgages!)

EDIT Sorry guys about the whining blog/divergence from the thread, I was paying bills this afternoon... you know how it goes, and feeling sorry for myself at the dwindling numbers. I am very lucky and thankful that I worked hard to stay out of debt and that my parents-in-law are helping us out too. I could be in a whole lot more trouble with no boat!

My post is a bit off topic, but this is a wonderful thread.



Callsign, as long as you do two things, you'll stay out of trouble as far as the boat is concerned.

1. have a coin under the mast for Charon the boatman, and
2. keep the black box in credit

Courtesy of John Vigor, who is a well known journalist and book writer who spent many years in South Africa, and was an accomplished dinghy sailor who competed in a number of regattas that I did also, although in different classes. He emigrated to the US by sailing his 30' yacht from Durban harbour and across the Atlantic. I was a fan of his columns as a teenager and am a regular reader of his nautically themed blog.

I christened her appropriately, with champagne and a plea to Poseidon but I didn't place the coin.....

...I thought of it, but didn't do it...

Part of me says, I'm not going to set myself up to pay out to old Charon there, and another part of me says, "You fool, you just off the pantheon with your hubris, something they despise!"

Hmmmmmmmmmmmmmm, methinks I have to figure something out. Does it have to be under the mast? What if I glue it to the frontside of the mast just about the step? Invisible from the crew, but still there? I think that's a good compromise. This would be a good "first time in salt water" kind of thing.

I remember when I was on a large schooner as a grade schooler and they pulled out the mainmast for repairs and there was the coin, forever embedded in the mast step- 60 years later. Kinda cool.

MIK my comment about needing a drawing of the throat lashing is illustrated here.



When you turn the head lashing which works upside down for the throat lashing every thing is upside down and makes no sense.

The hole is below the throat clew so serves no purpose in stopping the throat moving downwards - it's below it so cannot do its job. The lashing may be holding just about but nothing is really stopping it sliding downwards.

With just one hole then the clew has to be lashed close to the hole, the clew will then drop slightly below the hole as tension is applied.

In my view is should be lashed as with all corner lashings as you draw - one element holding to the boom and one element preventing sliding along the boom.

So either a second hole higher on the boom to stop the throat clew sliding downwards. One hole holds it in and the other stops sliding.

Or - something on top of the boom to stop sliding, a small saddle to pass the rope through or a glued and screwed block of wood.

Brian

Originally Posted by callsign222

The wrinkles disappeared, the sail filled. The boom definitely has some flex now, should I build a stiffer boom or is that ok loose footed? I think there's a fantastic discussion somewhere here on loose-footed boom construction, I could build one in a day, I'm thinking rectangular, two piece doug fir, 37x 52-60mm or so. Any ideas?

Hi Christophe
I wouldn't knock myself out making a new boom. Seriously, even if your boom bends 4" (which it doesn't appear to do) this only translates to a few mm at the ends.

But if you do, a box boom from junk 10mm finger-jointed pine wood like I made is cheap and quick. Taper it at each end and use any lightweight infills. I used Paulownia, but you don't really need so many. I was using up some Paulownia that weighs next to nothing. Mine easily takes my weight and much lighter than a solid boom too.
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Originally Posted by keyhavenpotter

MIK my comment about needing a drawing of the throat lashing is illustrated here.



When you turn the head lashing which works upside down for the throat lashing every thing is upside down and makes no sense.

The hole is below the throat clew so serves no purpose in stopping the throat moving downwards - it's below it so cannot do its job. The lashing may be holding just about but nothing is really stopping it sliding downwards.

With just one hole then the clew has to be lashed close to the hole, the clew will then drop slightly below the hole as tension is applied.

In my view is should be lashed as with all corner lashings as you draw - one element holding to the boom and one element preventing sliding along the boom.

So either a second hole higher on the boom to stop the throat clew sliding downwards. One hole holds it in and the other stops sliding.

Or - something on top of the boom to stop sliding, a small saddle to pass the rope through or a glued and screwed block of wood.

Brian

Brian,

Thank you for this explanation. Light bulb just went off. When I hastily tied this up last night, that's what I said to myself, the lashing is really the only thing doing any work here when I apply downhaul. Easy easy fix.