Thread: Start Building Another Dutch GIS

Originally Posted by Watermaat

Hi Clint,

A standard sail will probably make a nicer bundle. Especially the top leach batten of a "performance" sail will be in conflict with the yard. That's not a real issue if you are making a loose and wide bundle, but you will not be able to wrap the sail tight around yard and boom without taking that batten out.

You need to practice Ralph. It's not a problem

Well I will go for roach and battens. This will be my performance boat. The Deblois Street Dory will be my real sail-and-oar boat. That said, I do intend to use my GIS for sail-and-oar use. I guess I am 60/40 in favor of the Macnamera style sail. Thanks for thoughts.

Another plus regarding leech battens: As the sail gets old and a bit tired, the leech on a battenless sail tends to flap a bit, with battens it will hold a more efficient shape for longer as it gets older.

I'm curious as to any plus and minuses regarding using a stiff, hard finish sail cloth such as the McNamara sail versus a softer finish. I think Dabbler Sails (and Miks plans) recommended a softer sailcloth with more stretch for this type of sail.

Ian

I'm getting some flapping now in my leech, between the "handkerchief reef" and the peak. This is a large area that could use a leech batten. I'm not using any, for the record, but just from what I'm noticing.

Originally Posted by callsign222

I'm getting some flapping now in my leech, between the "handkerchief reef" and the peak. This is a large area that could use a leech batten. I'm not using any, for the record, but just from what I'm noticing.

Hi Christophe

When the leech starts flapping, what is the bend like in your yard?

Howdy,

Harder cloths need to be babied or they deteriorate quickly.

With raceboats we would use some large diameter PVC pipe to roll the hard finish sails around and were very careful that they didn't flap around on the beach too much.

By the end of one race season, despite the babying the clew third of the jib would always look pretty hammered from flapping around.

Racing people know the hard finish cloths are a sacrifice of longevity to get some extra performance. It is not so bad in a mainsail, but anything that is handled carelessly or folded up untidily or dropped in the bottom of the boat - or tied into a reefed bundle around the boom will suffer.

I would go with a soft or medium finish cloth.

MIK

This is a great question.

My yard has been getting more bendy as of late. I don't know if I'm getting some delam in there or not. Yes, the flapping has been exacerbated by the yard bending, but there's a difference in wind speed that now makes it flap more at lower speeds with less bend on the yard since the main is not hauled in tight to flatten the sail. There are two things going on up there now. But I can tell the difference, if that makes sense-- a local knowledge kind of thing.

The grain orientation in the yard may make a difference (it should make a small difference at least) in how bendy the yard is....each time it is sent up, if it rotates , the grain may be flatter making it seem more bendy. FFT.

Clint

Originally Posted by callsign222

This is a great question.

My yard has been getting more bendy as of late. I don't know if I'm getting some delam in there or not. Yes, the flapping has been exacerbated by the yard bending, but there's a difference in wind speed that now makes it flap more at lower speeds with less bend on the yard since the main is not hauled in tight to flatten the sail. There are two things going on up there now. But I can tell the difference, if that makes sense-- a local knowledge kind of thing.

As far as I remember from "the old days of dinghy racing" ; wooden spars tend to become more flexible over time. This is most appearant in the first year. Has nothing to do with delamination ( massive spars are even more affected by this ) but is probably due to fiber structure of wood (?). I know from wooden Finn masts, that the older ones became "tired" , still flex in a gust but did not straighten as fast as a new one. In those days sailmaker gave their sails a bit more leach-curve if you had a new mast. Similar happened with yards from different gaff-rigged dinghies.

This is an interesting post.

Today, I definitely noticed the increased bending. The yard always had a little kink in it, the grain orientation was mostly straight, and it was difficult to get opposing grain angles, I may have confused which end was which and slapped them together in the same direction.

Anyway, new yard and maybe a new boom probably for next year, a little cleaner and thought out in advance rather than the last minute mess I'm using now.

Howdy ... the thing to look for in terms of something wooden being overstressed is on the compression side the cellulose tubes with the greatest amount of compression will collapse just like a drinking straw collapsing.

This puts more load on the ones slightly in from the first lot which can compress as well. And so it works across the piece of timber.

This leaves a ragged dark line crossing the grain leading from the face carrying the compression towards the midpoint of the spar. More or less perpendicular to the axis of the spar.

Quite frequently you will get several of these dark lines.

If they don't appear then the spar is probably not being overstressed.