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Mast alternatives for the Weekender


Knut

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I am about to launch my Weekender and to be able to stay within 12 months from project start to launch I finally skipped the idea of making a light-weight mast using carbon fiber.

I am still wondering if anyone has direct experience to be able to actually compare the difference in boat behavior and performance if switching from the standard solid wood-mast to something substantially lighter? I have read a lot of forum discussions about stability of the Weekender and to me it makes little sense to put extra weight on the keel or in the boat bottom as long as there seems to be so much to gain from a lighter mast. A heavy mast is not making a lot of difference at small heel angles, but if it gets critical in a hard and sudden gust of wind at a larger heel angle, then the difference must be significant.

Anyone tried this out full scale? :?: :D

I am probably looking for motivation to build a new mast as a next project.

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I have to be honest ... even though I spent a lot of time making a lighter weight mast, I just don't think reducing weight in a mast that's just 12' above the water level is that important on a gaffer this size. There are so many other things that could provide a performance boost, such as a larger headsail. So I don't think there's really a performance edge with a lighter mast.

The concern with stability is probably misplaced too; I don't think the weight of the mast matters too much with the Weekender. The boat doesn't tip over easily in wind ... the cases we've heard about have been from accidental gybes that gain their power not from the weight of the mast, but the force of the sail full of air suddenly being stopped by the boom stopping after its swung over to the other side. In that circumstance, it doesn't matter how heavy the mast is, the momentum of that boom swinging over will tip you over quickly. I don't think the mast, per se, has much to do with the stability issue.

On larger gaffers they do recommend trying to lighten the weight of the gaff itself, but keep the boom heavy. The gaff on the Weekender is so light I can't see much advantage in using aluminum or a lighter material ... a 1 1/2" closet pole less than 6' long just doesn't weigh too much.

All the work I did wasn't exactly wasted, becuase I like the look of my mast. And I enjoyed making it. But from a practical standpoint, I don't think my hollow bird's mouth mast is any better from a performance or stability standpoint than the standard tapered 4 x 4 mast.

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Frank,

your comments make sense and thanks for the input. I completely agree that a larger jib is giving much more of a performance boost than any other modification that can be made on the Weekender. That is also why I have ordered a so-called Lapper jib, which I expect to use as the standard jib. Considering the wheather-helm with the standard equipment, I am sure it is better to reef the main rather than changing to a smaller jib, if wind picks up too much.

Regarding the mast weight you are probably right that it is not making much of a difference regarding risk of flip-over. However, my question was if there is anyone who has actually tried both the standard mast and a substantially lighter one on their own boat (or may be by personally sailing different boats?). And if so, if they have noticed any difference at all ( in performance, ability to carry sail in strong wind, heel angle etc).

I know I may be chasing marginal issues here, but after having switched to the Lapper and installed mainsheet and jib-sheet travellers I am just thinking what more could be done (with a measurable effect)?

Soon ready for sailing: 8)

Knut

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  • 3 weeks later...

OK - then I must conclude that nobody has tried both a standard mast and a real light-weight mast on the Weekender, to allow for first hand practical experience and a good basis for an opinion.

Looks like I will have to find a way of constructing one myself. Of course, the risk is then that my judgement (after all that extra work) will be slightly partial and not quite objective!

But, don't expect any report on this any time soon. First I have to do some sailing!

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Taking time out for sailing is definately a good thing. You need balance in your life, after all. Which is why I can't wait to build my next little boat (my wife is resigned to it now that I've built the deck, the dining room counter and re-finished the kitchen cabinets ... I just don't know what the next little boat will cost me in "Honey-Do" list items!)

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Frank,

you are certainly mentioning another reason why a new mast is not on the top of my actual to-do-list, but it is quite OK. After all the heat and sun out on the water I am sure that working inside (making new kitchen etc) in AC-controlled environment is not going to feel like a restriction any more. The variation and contrast in life is part of the fun! :D:D

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  • 1 month later...

Knut, I'd go with the 'birdsmouth' mast not only for the light weight but because it's easier and more fun than a solid spar. I made the hollow birdsmouth mast for my John Gardner skiff and it was much easier than I thought it would be. I made the staves and tapered them in an evening. Then I set aside a whole afternoon with my wife as a helper to do the big glue-up. What an anti-climax! We were done in 15 minutes! And I cut the staves from a piece of 'staging plank' spruce, about $15 for a 2" by 8"(actual size) 16' long. Plenty left over for a nice set of lightweight oars.

Steven

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Guest Anonymous

Steve,

I agree that the bird's mouth mast is a good alternative and there are some successful masts built this way out there also for the Weekender. I am going a different way for a couple of reasons.

I have access to carbon fibers through my employer.

I have very limited woodworking-tools and facilities where I live.

Using stiff foam sheets and carbon fibre set in epoxy I can make the mast even lighter than a bird's mouth design.

I expect to buy a sheet of foundation foam 4'x8' and 1.5 or 2" thick. As I understand these blue foam sheets are straight and pretty stiff. I will cut strips 3" wide, make a groove for a 3/4"x3/4" wood batten and glue the wood piece into the center of the foam material. I will end up having a 3" x 3" square foam length with a central wood core long enough to replace the central part of my current wood mast (from 4" below the eyebolts in the top to about 4" above the hinge).

This piece I am going to taper and give rounded corners exactly like my wooden mast and join it to the wood parts below and above by overlapping the epoxy and carbon fiber well onto the wood. When painted, this will look exactly like the wooden mast but the weight will be about 10-15 punds less and probably stronger.

I have been busy sailing, so the new mast is just a plan so far. But I am going to make this new design some time this year. Pictures and details will follow, including reports about how it feels in actual sailing.

Today on Biscayne Bay we had 10 to 15 mph with some pretty strong gusts. Sailing was like going on a bycycle ride in strong gusty wind. When the strongest gusts came, the only way was to let out on the main sheet and spill the wind pressure. Changing course was too slow respons. Beating upwind, the standard jib was a good help in maintaining speed through the waves. Probably I should have reefed the main and may be even had the lapper jib up, but when the waves start growing it is not a simple task to change the jib. I really wished I had the lightweight mast today (for safety margin in the gusts).

Reports to follow later.

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  • 3 years later...

When i was a child I asked my grandfather why he ripped the mast stock down the middle, cut a small dado or hollow [1/2"(wide)x1/4"(deep) in each half and glued them back together. He said that he was doing it to strengthen the piece. I asked him again when I was a little older and he explained in detail how taking the hollow out was for wiring and that he would glue them back together after spinning 1 of the halves 180 degrees so that any crown would work against the other, adding strength to the original stock. Then he would and I do the shaping of the mast or large spars. I never saw anyone do it that way until my grand uncle [Pop's brother] built a 44' pinky skooner. I didn't ask him why.

Then in south Florida I found a Jamaican builder following the same procedure so there must be some others that think along the same lines but everyone has there own way of doing things.

It makes sense to me in that the crowns working against each other not only straighten the mast but also add some degree of strength over solid methods.

Go figure. :idea:

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Big gains in performance can be had from Weekender and her big sister Vacationer, but it's a grab bag of many things that will eventually add up to a boat that points higher, is more maneuverable, faster, balances better and is generally more nimble.

Much depends on what you're after.

On low aspect, low gaff angle sloops like Weekender, windage, eddy making resistance, extra weight and trim are the biggest places you can make improvements.

Windage is quite high on boats with mast hoops, bull dog clamped splices, external halyards, lifts and jacks, etc. These things (plus many others) in concert with a low aspect rig and appendage (keel) limit the boats windward abilities considerably. If the boat went on a windage reduction program, that would savagely remove many of the charms in the vessel, you could gain 5 degrees of pointing ability. This doesn't seem like much, but across a 300 yard, close hauled course, this version of Weekender will make about 90 more feet toward it's next port then a stock version, which is a clean 10% improvement, which is impressive.

Eddie making resistance also contributes to poor windward and down wind performance. The bluff cutwater, untapered keel, bulbous forefoot, transom drag, etc. all conspire to eat away at the speed of the little yacht. Fairing the below water leading edge on the keel and tapering the after sections will help. Radiusing the chine will also help. Balancing the boat so her transom is just kissing the water while underway will do wonders for her abilities.

This brings up trim. Transom drag is the biggest thing I see in many Weekenders. She can't do well if she's dragging her stern, so every effort must be made to trim the boat (crew placement, coolers, etc.) so the transom isn't dragging a big wall of water behind her. Having the wheel doesn't help matters. It forces the helmsman to sit near the centerline and well aft. In a boat with a 13' LWL, you need to use your butt (literally) to help trim the boat. This usually means hiking out and moving forward some, compared to the normal steering position used on a wheel equipped Weekender. This is why the vast majority of small sailboats use tillers. Moving outboard and forward does two things. It move weight forward, so as not to sink the transom and it helps keep the boat on her feet (sailing more upright) which is the way she'll do her best. As wind strengths increase the more important this becomes, but if you're married to a wheel in a live ballast boat, you're against a rock, so to speak.

If you've ever watched small boat racing, like 420's, Lasers, Lightenings, etc. then you'll see the crew dancing all over the boat. After a while trends will develop and you'll note they move forward on certain points of sail, aft on others, the helmsman is actively hiking with the crew, etc. They keep the boat balanced with "live ballast" (the crew weight) and have found sweet spots that permit them to get the most out of their boat. This doesn't mean you have to pull a Chinese fire drill every time you tack, but you can get huge benefits from using crew weight to trim the boat properly. After a while you'll also find places where crew weight will make the boat handle or sail better. Next time you're out for a sail try this. Tie the helm down when on a beam reach, then move aft one foot. What happened? The boat will bear away from the wind. If you move forward one foot, the boat will head up. Hell you don't even need to steer, just slide your butt around the cockpit seats and she'll steer from trim changes. Want to point a few degrees higher, so you don't have to make an extra tack to get back to the dock? Get the bow to drop down a touch with crew weight and she'll come up into the wind (of course you'll have to trim sails to keep her in the groove). Believe it or not there are actually a few racing classes of sailboat that don't have rudders at all! They run back and forth along the rails to keep the course they want. Try it, because you'll gain a fair amount of knowledge about how your little pocket yacht behaves and what she likes (or doesn't) to make her go faster, turn sharper, etc.

Weight is the constant enemy of small craft. Designers go nuts trying to remove as much as practical and builders add things because it makes them feel better. Weekender can go on a pretty substantial diet. The calculations I make for Vacationer a couple years ago, while doing a new keel and rig for the Barnacle, suggest both Weekender and Vacationer can drop up to 50% (without going composite) of the full up completed hull/deck assembly and be no worse for it, structurally. Couple this with hollow spars and other weight savings ideas, like equipment aboard and it adds up to huge gains in performance.

It is certain that hollow spars can make a difference, but it's not a big difference if the windage is still there, drag is still present and the boat isn't trimmed properly. Alone light weight spars will account for very little hull speed, but in a buffet of modifications, can be a noticeable contribution to bettering her performance envelope.

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  • 7 months later...
Guest ib1boatnut

"Balancing the boat so her transom is just kissing the water while underway will do wonders for her abilities."

"She can't do well if she's dragging her stern, so every effort must be made to trim the boat "

Is this why some sailboat hulls seem to slowly rise up out of the water meeting the transom well above the water line, Or does the hull shape of some boats require an edge for the water to be efficiently released from like speed boats?

The other question with respect to the weight. When I was making my keel, which once had a dagger board I figured that what the reason for the 3/4" plys.

When it was omitted could stevensons had gone with thinner plys if desired or does the mast transfer that much pressure to the keel?

I dont plan on racing my weekender just curios about hull design/performance. Any book suggestions are quite appreciated. like the glued lapstrake book (thanks par)

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"Balancing the boat so her transom is just kissing the water while underway will do wonders for her abilities."

"She can't do well if she's dragging her stern, so every effort must be made to trim the boat "

Is this why some sailboat hulls seem to slowly rise up out of the water meeting the transom well above the water line, Or does the hull shape of some boats require an edge for the water to be efficiently released from like speed boats?

The other question with respect to the weight. When I was making my keel, which once had a dagger board I figured that what the reason for the 3/4" plys.

When it was omitted could stevensons had gone with thinner plys if desired or does the mast transfer that much pressure to the keel?

I dont plan on racing my weekender just curios about hull design/performance. Any book suggestions are quite appreciated. like the glued lapstrake book (thanks par)

I think the Weekender might do better with some of its heavier sailors if the aft end of the boat were wider.  Many have found that putting weights up in the forecastle helps with the trim.  But weight in a dinghy-type of sailboat with a flat bottom is probably not as good as more flotation aft.  The Potter 15 is a similar sized boat, and the cockpit is much wider at the back (and more comfortable for the occupants.) 

The mast on a gaff doesn't put that much compression stress on the keel.  Small gaffers are not rigged with the same kind of tension you see on marconi rigs.  One good thing about the Weekender is that its probably overbuilt and under-canvassed, a good thing when your builders are often first time boat builders (and sometimes first time "anything builders").  I think that the deep forefoot of the keel probably helps balance the boat; Bolger had a larger sailboat with a huge centerboard forward and a barn-door rudder aft, and his calculations for the unusual design were in an old edition of Wooden Boat Magazine.  It was an interesting design, and I thought it had similarity in an odd way to the deep forefoot of the keel on the Weekender and the high-aspect rudder. 

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I don't think Weekender's aft sections are too narrow. I do think she's way over built, per the plans, with many unnecessary pieces which adds complication and effort to the build.

Yes, IB1, the sterns you see that are well clear of the water, usually are intended to permit the water flow around the hull to be minimally disturbed. Where as the crisp edge seen on the stern of powerboats and sailboats with the ability to plane is necessary so the water can release cleanly when up on plane.

You can actually have a boat that planes with a raised transom, but it's a hull type not often employed anymore and is limited in S/L ratio (speed/length) it can achieve (read, speed potential), unless really narrow (over 7:1 length to beam).

Frank is right in that compared to Bermudian rigs, typical gaffers aren't as "highly strung", so compression loads aren't as high, but they're still higher then you'd imagine. When I design a mast step I size it to easily accept three times the displacement of the boat. It will only see this occasionally, like when sliding down the face of a wave and you're nearly stopped by the wave in front. These forces are enough to shove a mast right through the bottom of a boat.

I have a 18' sailor that all up, rig, sails, boards, everything is less then 300 pounds. Yep, it's quick, but this is typical of all performance oriented sailboats. Weekender could easily be built at half her weight will little sacrifice.

A heavy mast does slow you down, especially when you've got a fair amount of heel on. It forms a turning couple that tries to force the boat into the wind. Much of the heavy helm or weather helm comments can be traced to, too much angle of heel for a flat bottom on a short LWL, carrying a overly heavy set of spars, kind of boat. Flat bottomed sailboats want to sail upright, for them to do their best. Dig the chine in deeply, with excessive heel and you slow down, the helm gets heavy and sluggish, plus your leeward side is piling up a wall of water, that must be dragged along with the boat.

I think I remember the Bolger boat with the forward board you mention Frank. It was an interesting concept, but if memory serves me it also had a smaller "trimming" board aft. These tandem board boats are fantastic on long cruises as they can self steer with proper placement of the boards. They can be slow in stays if you lose the sequence of board retraction and deployment.

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I recently sailed on a custom 54 foot sloop. She has tandem boards- a dagger board forward and a trim board aft under the cockpit. You could adjust the boards and walk away. The boat would sail her course for as long as the wind didn't shift. Pretty nice.

Here's a shot of Laura and I "tending the helm" :D

aV1eYKkJ.jpg

The boat is named Cannibal and has competed in three Trans Pacs, winning her class in one of them. After that she made two circumnavigations, plus a by sea transfer from the Pacific coast to the Atlantic, and then to the Gulf of Mexico. POWERFUL boat.

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