linen as a sail material.

[dsuursoo]

the multihull would be a test platform, when it comes to such. i want to make a rather large schooner of 1790's design(mostly, heh. they never had the engineering i've got), and i'll admit, i'm interested in going totally period with as much of it as i can.

[TeddyDiver]

The stiffnes of a multi is the reason of my doupts with such sail materials as linen. With more traditional hull forms counting more ballasted stability sails aren't stretched to their limits in sudden gusts..

[dsuursoo]

Originally Posted by TeddyDiver

The stiffnes of a multi is the reason of my doupts with such sail materials as linen. With more traditional hull forms counting more ballasted stability sails aren't stretched to their limits in sudden gusts..

a fair point. makes me glad i'm planning on only using it for experimenting inshore, in the puget sound. but, for the big boat(the main reason i'm researching it), it'll be a monohull, and should be more forgiving.

[Brent Swain]

Throw a few moth balls in your sailbag and mold won't grow there. May stop rot too.
I'm painting my dacron sails black with acrylic paint to keep the UV out, next time I sail south. Darker sails last far longer, being far more UV resistant.
Just look at those US pyjama flags when they have been in the tropics too long. The red stripes last far longer than the white material. White in synthetic fabric is just another word for transparent. Any colour reduces the transparency and thus the UV penetration.
Brent

[dsuursoo]

you're not worried about the weight increase? one of the main objections to older cloth sails i've seen is weight. most sailors(if you take the admiralty's stance) want to work as little as possible. so a featherweight sail they don't have to maintain, doesn't need replacing as often, and it's easy to haul up? and thusly was the transition sealed. synthetics do make sense, i'll admit.

but then, if i myself were all for synthetics and other things that seem sensible, would i use a hand-carved oak bow with handmade arrows when i go hunting(or my handmade flintlock, for that matter?), would i drive an old car that needs service more often? would i want a gaffed schooner with linen sails?

heh. just me i guess. synthetics do make sense in many ways, and they're easier to get.

if i get synthetic sails for any boat i sail long distances, likely the sails will be blood red.

sure, less visible at night.

but holy crap it's a wicked looking color above a wooden schooner.


arr.

[rwatson]

Originally Posted by Brent Swain

Darker sails last far longer, being far more UV resistant.
White in synthetic fabric is just another word for transparent. Any colour reduces the transparency and thus the UV penetration.
Brent

Hmm - I had always believed that darker colors absorbed more rays of all sorts - and white reflects.

Still do too!

[dsuursoo]

Originally Posted by rwatson

Hmm - I had always believed that darker colors absorbed more rays of all sorts - and white reflects.

Still do too!

most synthetic fabrics, when undyed, are actually clear. they look white because of the diffraction of light through the fibers. you can actually see through nylon fibers, oddly.

well, in fabrics darker does tend to allow less light through. the dye absorbs light and reflects less(which is why you can see through a white t-shirt but not a black one, more or less), allowing less light to be reflected to the other side.

also, he's planning on coating his sails altogether. that alone would protect them.

though i wonder about the durability of acrylic on a constantly flexing surface... i have a feeling it'd crack and flake in pretty short order. testing recccomended.

[rwatson]

you cant "reflect light through to the other side". Something is either transparent or has gaps before light gets through.
Its no co-incidence that the majority of sails are white, or as light in colour as possible.

yes, the coating on sails would need to be super flexi. It would add some weight up high as well I would expect.

[dsuursoo]

Originally Posted by rwatson

you cant "reflect light through to the other side".

fiber optics. it's diffraction/refraction. less than 100% of the light makes it through. a lot of synthetics are translucent at the fiber level.

Originally Posted by rwatson

yes, the coating on sails would need to be super flexi. It would add some weight up high as well I would expect.

oh yes, totally in agreement here. careful, he must be. wonder how much weight it'd add? i myself would rather use a latex base, it'd handle the heat and flexing better, i think.

dunno how it is for opacity though.

[Meanz Beanz]

Originally Posted by rwatson

Hmm - I had always believed that darker colors absorbed more rays of all sorts - and white reflects.

Still do too!

Yeah but they can get far more effective UV blocking (I think he called them PCB's from memory...) in the darker colours... thats why the black nylon cleats and deck fittings last longer than the white and why black is used more often. I had a guy from Ronstan explain it to me once when I worked in chandlery. I agree though its a bit counter intuitive.

[dsuursoo]

Originally Posted by Meanz Beanz

Yeah but they can get far more effective UV blocking (I think he called them PCB's from memory...) in the darker colours... thats why the black nylon cleats and deck fittings last longer than the white and why black is used more often. I had a guy from Ronstan explain it to me once when I worked in chandlery. I agree though its a bit counter intuitive.

probably along the lines of light not penetrating as deeply in darker colors.

i think the color added in nylon is a dye that's applied to the outside of the fiber. perhaps in the bonding media?

eh. not something i understand. too much chemistry.

[Meanz Beanz]

It was just the pigments ability to carry the UV blockers... I assume that the UV blockers would have turned a white fitting some darker colour if used in the same way that they can in a black fitting. Its a bit of extrapolation but I assume that a similar thing applies with the sail cloth. All things being equal the darker colour is probably not as good BUT because its dark they can mix in more of the UV blocking agent... therefore it ends up better performer in the sun contrary to what should be expected. I am guessing about the sail cloth but I know thats the case with the nylon cleats and similar deck fittings... at least those made by Ronstan.

[dsuursoo]

works for me. it was always one of those things that made me hesitant with larger boats(like when i was looking into getting a huntermarine 45 centercockpit), due to the size of the sail and cost of eventual replacement.

sure, ten years off, but who wants to drop 20 grand on a new sail?

[Brent Swain]

I have black poly tubing on my rigging that has been out in the sun since 1976 and made many trips across t he Pacific. Its in as good a shape as the day I put it on. Anything but black would have broken up in three years.
Black absorbs heat, but blocks UV. Heat is not the problem . UV is.
Black poly rope drastically outlasts yellow or other colours.
I've seen acrylic stay on sails for decades. The Canadian flag I painted on my windvane in 2,000 in Samoa has just faded. Easy to slop more paint on, and far cheaper than buying new sails more often.
Water stays fresh in black poly gerry cans , but goes swampy in red ones . Sceptre sells black ones for the military . Civilians get the useless ones.
Hold black plastic up to t he sun. None comes thru including UV . Hold any light colour plastic up to the sun. All kinds of light comes thru. Tropical people are dark for the same reason. If northern people were as dark they would suffer extreme vitamin D deficiency.
Don't mistake heat for UV.They are two totally different animals.
Brent