all right the mast is a noodle

[2MeterTroll]

So i need to

A. build a new mast.

1. hollow
I have a bunch of Ash that would be not light but would be strong and pretty forgiving. not very rot resistant but then again how rot resistant does a mast actually have to be?

2. bamboo

timber bamboo could be gotten and i could sheath it in glass.

3. solid fir or ceder.

I know fir works but its heavy, and cedar works but its kinda hard to find in straight round buck skin form. it can be done however and i know just the place to do it.


B. find a mast from some one else.

Any of you folks got an old mast laying around about 19feet long and not very flexible. I will use aluminum or wood for now.

[David G]

E,

Call Kim over at Columbia Marine Exchange to see what she's got by way of a used mast (and sails?):

http://columbiamarineexchange.com/

I'd aim for a hollow fir stick. a reduced-scantling hollow ash mast would be interesting to try... but only if the ash is on-hand (free).

I'd steer clear of wrc, as it doesn't have the strength, i.e. would have to be increased in size, plus it's so soft that it'd bruise & dent when looked at. Spar varnish is not good idea, therefore, 'cause of the hard-boiled-egg effect. Soft substrate which compresses easily, fracturing the coating, leading to moisture intrusion, leading to unsightly mildew spots. I'd oil it if I did it at all. It'd have to be beyond free - or there'd have to be some unimaginable sore of weight issues going on - for me to consider it.

What's up with the first stick? Watcha mean "noodly"?

[JimConlin]

Would applying stiff materials like ash, glass or carbon uni be practical? Think 'Mast Viagra'.

[2MeterTroll]

thanks David
I'll give her a call in the morning. Erica and I want to go for a sail and see how it all shakes out. the rig worked like a charm on the Big Food. Erica built one heck of a sail. to the point where she was getting asked if she did it professionally :)

the Ash is on hand in the car port but i dont really want to wait that long before we get the Tari Tari out on the river under her sail.

I can get buck skin PO cedar from a friend down south eventually.


well it is/was very very very flexible we stuck the rig on and could get a nice s curve out of it. so we decided not to use it for fear of it breaking under load. I dont think that would have been good so Tim Yeadon needed a couple spars and now he has a nice solid 20' 70Yo spruce mast to get them from.

the boat is bloody awesome and all the reservations melted away wen we got side slop on the way to the boat ramp across the lake. she's a good stable work platform. so now i need to build a yolua and oars. but we want to take her out under sail as soon as we can.

[David G]

E,

Good to hear. Are you gonna bring her to Eugene this weekend? There'll be a large number of Coots there to admire and advise:

http://www.coots.org/mb/EYC/index.html

And - some fotos from last years smaller, inaugural event:

http://www.andrewlinn.com/080816_Fern/eyc_start.htm

Cheers,

[Todd Bradshaw]

I've never seen an ash mast. I have, however, used an ash setting pole for canoe poling and found that, compared to a fir pole of about the same diameter, the ash one was incredibly bendy. It might have had higher breaking strength, but the feel was as if it was spring-loaded. We found out the same thing with some double-bar portage yokes that used a round bar/thwart in front of you and another behind you with shoulder straps running fore and aft between them. We thought we would get clever and substitute ash for the fir bars called for in the plan, figuring that ash would finish up nicer. With every step, the bars bounced so much that the canoe bottom hit you on top of your head. They were quickly replaced with fir bars and the problem was solved.

[2MeterTroll]

E,

Good to hear. Are you gonna bring her to Eugene this weekend? There'll be a large number of Coots there to admire and advise:

http://www.coots.org/mb/EYC/index.html

And - some fotos from last years smaller, inaugural event:

http://www.andrewlinn.com/080816_Fern/eyc_start.htm

Cheers,

We will try our best to get down. it will take borrowing the trailer again. i think we can use the Jeep till the week after. but i have to run it by the boss. i will be out on the river all week in the umiaks so we will have to see.

[2MeterTroll]

Thanks Todd thats good info that i dont have. I will try to get a fir mast if i can. i think i have the wood to glue one up. i just need to decide birds mouth or box.

[Thorne]

There is a good reason that ash was used for the handles and shafts of pikes, halberds, partizans, battle axes, etc -- it is VERY bendy and resists breaking. Would not make a good mast if stiffness is required.

DF will work well, fairly easy to get in the correct lengths. If you can handle the weight, just epoxy 2 2x4's together and shape with a power planer and belt sander.

[2MeterTroll]

I dunno Thorn i always replace with oak cause the ash seems to just take only so much then shatter. I am however not going to do ash if i have to build it my self . I will take some of the fir i have and cut it up for the mast. i am just hoping i can get something that will serve in the meantime.

[David G]

I've never seen an ash mast. I have, however, used an ash setting pole for canoe poling and found that, compared to a fir pole of about the same diameter, the ash one was incredibly bendy. It might have had higher breaking strength, but the feel was as if it was spring-loaded. We found out the same thing with some double-bar portage yokes that used a round bar/thwart in front of you and another behind you with shoulder straps running fore and aft between them. We thought we would get clever and substitute ash for the fir bars called for in the plan, figuring that ash would finish up nicer. With every step, the bars bounced so much that the canoe bottom hit you on top of your head. They were quickly replaced with fir bars and the problem was solved.

Todd,

Admittedly, The ash would be an experiment. I don't know what flavor of ash he's got, but wouldn't be surprised if it was local stuff. That'd be Oregon Ash - which is comparable to the more commonly seen White Ash from the Eastern part of the US... and not as rot prone as the less expensive black or green ash.

I'm certainly no rig designer, but one of the reasons I thought it might be feasible for his situation, is his batwing sail. That's a type of balanced lug, and my understanding is that a balanced lug doesn't mind a bit of flex in the spar - as a means of de-powering in a gust. In his skinny little sampan, I'd think that'd be a good thing. Or, maybe you think the ash would just be TOO bendy to be compensated for by tuning the scantlings? Or maybe there's some other factor I'm missing?

Cheers,

[2MeterTroll]

I would like to experiment with the ash. but for an all round rig at this time i think i would like to go with a known quantity and folks seem to know fir is good. i am at the moment balancing speed to the water with time to build. its like summer you know and we would like to do more sailing than building for the next couple months :)

[Todd Bradshaw]

David, all the bat-wing sails that I've built, and all of them that I can think of off the top of my head were basically a form of big-roached gunter sails, not lugsails. The entire luff is aft of the mast. The topmasts vary from something sturdy enough to really be called a topmast to something more flexible that is more like a nearly-vertical, extra-sturdy batten, but they don't cross ahead of the mast. You can certainly have fully-battened lugsails, both in terms of those seen on some of the old canoes where the battens' main function was quick slab reefing, and in the form of Chinese lugs (fully-battened balanced lugs with a hollow luff and large roach) as well as a variety of hybrids, but I've never heard of a lugsail that's a true bat-wing.

The Chinese did use mast bend to leeward as a depowering/shock-absorbing tool and it's always a possibility on any rig as long as it doesn't temporarily screw up the sail shape and luff tension too much. There is a limit though, to how much you want your rig moving around on you and how small of a gust you want to be able to do it. You are, after all, trying to harness the power of the wind and a rig that's falling off to leeward with every puff doesn't tend to be very efficient. I just figured that if his current mast is too bendy and he builds a replacement from ash - he ain't seen nothin' yet.


http://webpages.charter.net/tbradshaw/Batwing.jpg

http://webpages.charter.net/tbradshaw/Balanced-lugs.jpg

http://webpages.charter.net/tbradshaw/Chinese-Lugsails-copy.jpg

Ya' know....as much as I bitch about how much sailmaking has screwed up my knees and how tedious it is, and how I no longer build big sails or plain white sails, you have to admit that I do get to build some really cool stuff!

[David G]

Todd,

Perhaps I was sloppy in my nomenclature. E has what I guess you'd call a fully battened lug sail - shown here on another boat:

http://lh6.ggpht.com/_Qk62rRa2hGc/Sm0Mdj-SY-I/AAAAAAAABDc/9-my4u_U4Ds/s400/IMG_0243.JPG

My point was that it's a form of balanced lug. And what I was attempting to verify with you was the notion that such a rig would benefit from the flex - for depowering in a gust. I guess it's a moot point, however, he's decided on fir. Chickenspit bastid won't be convinced to satisfy my curiosity on his boat :p

Thanks,

[Mrleft8]

Spruce makes a nice mast....

[Yeadon]

Todd,

Perhaps I was sloppy in my nomenclature. E has what I guess you'd call a fully battened lug sail - shown here on another boat:

http://lh6.ggpht.com/_Qk62rRa2hGc/Sm0Mdj-SY-I/AAAAAAAABDc/9-my4u_U4Ds/s400/IMG_0243.JPG

My point was that it's a form of balanced lug. And what I was attempting to verify with you was the notion that such a rig would benefit from the flex - for depowering in a gust. I guess it's a moot point, however, he's decided on fir. Chickenspit bastid won't be convinced to satisfy my curiosity on his boat :p

Thanks,

... not just "on another boat." That, my friend, is the Big Food. :D Shown above, I have just gybed and am reaching toward the dock. (Also ... to make the sail rig fit my 12 foot spar, Ernie reefed the bottom three panels with waxed thread and some quickly-devised lazyjacks. This is worth noting, as the sail is actually about 180 square feet. Show above, it's only 90 square feet or so.)

My feeling after using the junk rig for an hour or so was that because the sail was basically square-ish in shape, a lot of wind/energy was spilled by the leech's peak during a gust. Couple that with a solid spar able to flex a bit to absorb energy and dump wind, and I think you'll be fine.

I think you could basically conform to the scantlings needed for a balance lug of a similar size.

Edited ... okay, one more note. With all those battens, this was a very flat sail. You ended up sailing it a bit loose, it seemed, in order to keep a bit of belly in the sail.

[Canoez]

http://webpages.charter.net/tbradshaw/Chinese-Lugsails-copy.jpg



Is that a polished Grumman?

[Thorne]

That's right, Tim, don't let my Twin get away with referring to your lovely baby as just "another boat" -- de noive o' dat guy!

Was all that sail ahead of the mast an issue for balancing the rig? Looks like you'd get more lee helm than usual.

[Yeadon]

The sail balance was fantastic, actually. I'd love to get the junk's dimension's from Ernie and Erica, then draw it out to find the CE and CLR difference.

One thing about having that area in front of the spar ... when you gybed, it was so peaceful and quiet. That front area acted a bit like a brake as the trailing leech swung around.

The sail was also very easy to backwind when stuck in stays, as I have a long straight keel without any rocker.

I do think for my boat, I'd go with a balance lug versus the junk rig. The ephro device used to help trim the sail is a bit funky. However, I think Ernie will figure that one out in the end. Also, for a small sail and oar boat that needs to reef early and often, I think the balance lug with a light boom might be better. You could avoid having to use lazy jacks, which means that when you drop the halyard and douse your sail - you still have the lazyjacks hold the entire rig a foot or two above the thwarts. You have to then release the lazyjacks before rowing. Not a big deal, but it is one more thing to mess with.

Overall, the junk was a really cool sail. On a more sailing-oriented boat, versus a sail and oar boat, I think it might be the way to go.

[David G]

... not just "on another boat." That, my friend, is the Big Food. :D



Tim,

Of course I recognized Big Food. I just didn't want to publicly identify her - for fear that you've be embarrassed to be associated with a vessel whose paint scheme is upside down :p

Seriously - she's a gorgeous boat, and deserves recognition. Thanks for the feedback on the rig.

Cheers & ColdCold Beers,

[Todd Bradshaw]

David, "benefitting" from spar flex is a pretty slippery slope. There are exceptions, like the big Chinese ships (which still had masts the size of telephone poles), or boats like Stars that have mast rams and lots of adjustable wires to control and adjust upper and lower mast bend and its effect on mainsail shape and draft, or even one-design boats like Lasers (once you have thrown away enough test sails to finally get a design where the mast and sail's cut actually work together). For one-offs and most dinghy-sized boats though, you're almost always better to make your spars just as stiff as you can possibly make them, given the materials and diameters available. Depowering in a gust by having a leaning mast or a yard or boom bend is far less important in the long run than having good sail shape most of the time.

Lugsails are no exception. Since their luffs are out ahead of the mast, flying in space, proper luff tension is not easy to come by and is one of the most important factors in getting good performance and maintaining the sail's designed shape. Excessive mast bend usually has a very detrimental effect on these factors. What you might gain in having a bit of shock absorbency (ability for the mast to lean over to leeward and spill wind) is likely to be out-weighed, big-time, by that same flexibility temporarily reducing or changing luff tension, moving or changing the sail draft and possibly ruining the sail shape with each puff. It's very difficult to design a sail with decent all-round performance when the shape of the spars supporting it will vary constantly in use. If in doubt, for the best all-round sail shape and performance you are much better off 99% of the time to build your spars just as stiff as you possibly can. Otherwise, you can very quickly get into a situation where your sailmaker can't design you a sail that has the ability to work decently through a reasonable range of conditions.

The relative stiffness and bias-stability of modern Dacron in the 3-5 oz. range makes this even more of a problem. For a number of very practical reasons, it's usually the hands-down choice as the best all-around material available for small boat sails, but in use, it really doesn't stretch much at all. A certain amount of shape adjustability can be built-in with the cut, but for the most part, the shape you build is the shape you get. Create a scenario where the spars supporting that sail are constantly changing shape and you can very quickly get to the point where the sail can't make those changes with them.

I'd really like to see the battens (bamboo sticks, I presume) on that orange lugsail turned around so that they point the other direction. The stiff end should be the aft end, not the front end. It might help cure some of that massive leech hook and move the draft forward, closer to where it's supposed to be.

[2MeterTroll]

Ok let me first tell you guys this is our second sail we have built I am not trying to be argumentative. so i am going to apologize in advance if it sounds like i am arguing. I am learning and i need to discuss and defend and have things explained to me on this. our learning curve is pretty vertical at the moment and i want to learn and this is how i need to learn.

Ok this sail is not Dacron it is nylon canvas so it has a bit of stretch to it. the rig is balanced for a 19 foot mast. the reason the battens are in what looks like a backward configuration is that on the first junk sail i built the leading edge tended to cup to much and i didnt get a good S curve to the sail under load. this one has a very nice shape when it is full with a gentle luff and a full leach edge. (i think those are the correct terms). I dont have a much sailing experiance so i am working on observation and applying what i have in fluid dynamics and hull warping for big ships. its my understanding that you have two places that you are generating power in a sail. just behind the leading edge and just before the trailing edge.

with this in mind i designed the sail so it would create this duel form. from my observations in fluid flow dynamics an S curve can swim effectively up stream if it is formed correctly the viscosity of the medium determines the shape that will be most effective to give you the draw and push effect.

thanks for the Reply's and brain power you folks are putting into this.

[Peerie Maa]

2. bamboo

timber bamboo could be gotten and i could sheath it in glass.



If you can get a bamboo pole of the right diameter all you need to do is put on a tight whipping between each node to prevent splitting and you have a strong thin walled hollow mast. Was quite common on the Norfolk Broads for spars. If you need a halyard sheave glue a wooden plug in the top and work it to provide what you need.

[Todd Bradshaw]

Explain what you mean by "S"-curve.......'cause there ain't no "S" in sailing....:)

I assume you already know that real junk sails were cut perfectly flat with heavy, stiff battens to keep them as flat as possible, but with excellent twist control due to the bridle/mainsheet systems running to the aft ends of each batten, along with a parrel at the mast for each one. They're really fascinating sails and refreshingly non-mainstream compared to western sails. Once you start giving them the characteristics of western lugsails though, I think you'll find that the same sail shape / draft and draft placement / entry angle / leech shape guidelines apply which would apply to any western balanced lug (along with the practical problem of bending your battens backward over the mast on one tack). Its just a western lug with a different profile.

You clearly aren't going to get clean airflow from a leech that's hooked that much, which is why I mentioned the battens. A set of leech telltales would most likely be able to demostrate this. The draft in the sail is also probably running 60%-70% aft, as opposed to 45%-50% on a typical balanced lug. Flipping the battens is the best way that I can think of to fix this - move draft forward and flatten out the leech (though how well it works may depend upon where you cut the maximum draft into the sail in the first place). At the same time, you still need to maintain good luff tension or the whole thing won't work.

Just about anybody can make a sail, and I firmly support those willing to try it. There are some pretty good books out there which document the process and the design phase and principles in great detail. There are also cases and reasons that builders might want to deviate somewhat from the straight and narrow, time-proven guidelines of sailmaking. Some of them end up working better than others. The question that always comes to mind though when told that an unusual approach works is always "Compared to what?". I tend to wonder this most of the time when I see people changing the basic specs and design principles of junk sails and tossing 6,000 years of Chinese engineering and experimentation out the window. It would certainly be interesting to have the time and money to do all sorts of experiments with small sails, but given only the means to build a handful of them I generally lean toward what has been proven.

...and yes, the owner of the aluminum canoe decided that he wanted to be outrageous and art-deco and polished it. In its own way, I kind of like it. I had a friend back in Illinois who owned an all-aluminum motorboat that looked kind of like a Simmons Sea Skiff, except it had a full cabin (also aluminum). He polished it similarly and it was something to see. When you got into it on a hot summer day it looked like you were boarding a toaster oven - and it felt like it, too. It was the hottest cool boat I've ever seen.

[2MeterTroll]

this is an s curve in down wind: http://www.geocities.com/kp_diver/EJbox24-24L-Web.jpg

this blog mentions several sources i could find on junk rigs it also has several pictures of junks under sail. one thing i keep noting is that Brian platt's junk rig and Joshua slocums junk rigs look much like the pictures of traditional sails with a slight s shape. while the more modern junk rigs tend to belly out rather than develop the S Shape i see in the old photos.
http://proporzionedivina.wordpress.com/2003/10/

I am not going against 6000 years of testing and development i am trying my level best to follow that development despite the last 20 years of western eyes trying to make a junk rig into a balanced lug.

it is not easy to fight our tradition and try to make a sail that performs like the originals. if you have more modern data on the traditional set ups on junk rigs i would really like to see it. i feel at times that because i am questioning moden thinking i have drawn a target on my back.

[Yeadon]

This "s" that Ernie is describing. I saw it, but found it confusing. There were times that the luff was lightly backwinded, yet the leech was completely powered up. I also saw the opposite occur, but on a different point of sail. Both situations I remember having plenty of power, but was unsure of how to read the sail. Also, I really wasn't paying close enough attention to better describe it ... Lake Union is really, really busy on the weekend and I was avoiding boats.

I'd really like to mess with the junk a bit more.

[2MeterTroll]

http://www.allstar.fiu.edu/aero/images/fig18.gif

number 4 from the top is the shape of foil i was trying for. it is consistently the shape i see in the pictures of junks under full sail in the old photos.

Mr Savonious uses it in his turbine design. though not as efficient as it could be it does help the betz limit. this also has discussions of foil shape and those discussions parallel what i Have seen in the junk rigs. http://eduhosting.org/windpics/wgfoil.html

since the sail is a drag based air foil and and what i have observed on the first junk rig made to spec seems to act as a drag based air foil. i have tried to compare all the data i could find.

my hypothesis is that the Chinese developed an adaptive drag type air foil design.
that shares some traits of a super critical airfoil on a two dimensional structure.

the max disturbance (shock wave) acts to create the leading curve of the trailing foil shape. in effect you have two wings in one sail drawing you along.

hmm i hope that was clear enough if not please ask for more detail.

I am going to add a few links that i have been using to help me with all this so please forgive me if it looks like i am getting a bit out of sails and into wings. there is just not that much testing that is sail specific.http://www.coe.uncc.edu/~rkeanini/lowreyn/LitRev.htm (http://www.coe.uncc.edu/%7Erkeanini/lowreyn/LitRev.htm)

http://www.aeronautics.ws/optairfoilmaxlift.htm

http://www.ima.umn.edu/industrial/98_99/strumolo/strumolo.html

[Todd Bradshaw]

"my hypothesis is that the Chinese developed an adaptive drag type air foil design that shares some traits of a super critical airfoil on a two dimensional structure."

I'm certainly not a junk rig scholar and you could be right, but my impression has always been that the Chinese figured out that you could move a boat decently with something that isn't what most of us think of as an airfoil and then went on to develop a dynamite delivery and handling system for it. The system allowed excellent control over the sail with fast, easy reefing, minimal flapping, easy up and down, no stays and created adequate structure and strength with a minimum of technology and with inexpensive, locally available materials. In the process, they showed that it will also tolerate a certain amount of distortion from the designed and built-in flatness at times and still work reasonably well in general. That's what I tend to get from the old photos, rather than that they were trying to create a specific non-typical airfoil shape.

Having seen sails that were cut dead flat (and knowing it because I built them) and seeing with my own eyes that they were pretty much dead flat in use, while watching them push a boat along nicely is pretty cool. The owners sit there, sailing along with a big grin, not knowing that they don't have a "real" airfoil overhead. From what I've seen, the pointing ability is nothing to write home about, but they will go to windward to a reasonable extent. Very neat stuff and well worth experimenting with. The claw rig is another old one that is particularly interesting.

[2MeterTroll]

he he he thats what i said :) I do not think it was on purpose but a happy coincidence.

I marvel at the flat rigs and the junk sail in particular. for the ease in use and control you have over the sail. but i like many, i assume. have to have a place to stand for understanding what i see. so i am matching what i see with what research i can get.

I have not looked into the claw yet :) one challenge at a time.

[James McMullen]

How about a claw-rigged cat-yawl with one big claw sail and one tiny one. You could then name it Fiddler.

[Todd Bradshaw]

After you've figured out the Chinese sails and digested the Crab Claws, the next step would be to study the true speed demons of the seas - The Vikings! Everybody knows that Viking ship sails were actually made from hundreds of stunt kites linked together and that the boats planed along at 25 knots riding on just their oar tips and the bottoms of their keels..... and they could do it on snow, too!

One of these guys sent me this material a few years ago to see what I thought about it. I read the entire thing, which does have a fascination of sorts, but I must admit that my initial reaction was to wonder if he had stopped taking his meds? My other reaction was simply "show me that this works" - photos, video or something. As far as I know it still hasn't happened, but if you're bored, it's worth a look for entertainment sake if nothing else.

http://www.sjolander.com/viking/

[2MeterTroll]

no thanks i have enough on my plate ATM.
Since i have to work with fluid flows in stoves the work with the junk rig just becomes part of it. trying to figure out viking myth from viking fact is to far removed from my base research.