homebuilt wing mast

[village idiot]

Anyone got plans / ideas on building a wing mast for 7m tri ? need to build a mast 10.5-11m with aprox 250-300mm cord .I'm thinking gaboon ply/foam composite with carbon reinforcing.? any suggestions.
thanks. :)

[Gary Baigent]

The first jpeg is Flash Harry's that is 9.1 metres x 0.450 length to chord, has a curved above hounds trailing edge/luff - but if you want a straight version, just reverse leading and trailing edges. This is a larger chord than what you listed and also a metre or so shorter - but you get the idea. Second image shows a comparison with Groucho Marx's cross section. Harry's mast is now over 20 years old, 4mm ply I beam, frames of same, skinned with 3 mm with carbon at hounds and other high load places, weighs less than 20 kgs with all rigging.
Third image is David Knaggs wing mast for his foiler - which still survives but moulders away at the bottom of his garden.

[CTMD]

Build methodology for a carbon mast of my design here (http://www.gust.ax/gallery/mast/08-04-23/) then
here (http://www.gust.ax/gallery/mast/08-04-24/)
send me an email if you want help with laminates.

can also be done with foam instead of ply.

[jpquattro]

Hi all.
I am a new member, I write from Italy. I am building one 8 meter catamaran based on a Paul Fisher design.
The project call for a 10 meters mast with a single shrouds order and diamond.
The mast in this thread is almost of the correct size...
But it appear really light, with thin skin...
Some rough calculations suggests that it is close to the limit for me, then the question is: can you detail something about the number of shrouds and spreaders used?

Paolo

[Gary Baigent]

You talking to me, jpquattro? Guess you are since Flash Harry's mast is thin skinned. Three shrouds, no spreaders - but there are a number of layers of carbon run and spread over the halfway point area between hounds and base. FH is a light boat, around A Class weight, and the mast is actually 25 years old and has never broken, yet has been in some horrible sailing conditions, when my heart was in my mouth.

[jpquattro]

You talking to me, jpquattro? Guess you are since Flash Harry's mast is thin skinned. Three shrouds, no spreaders - but there are a number of layers of carbon run and spread over the halfway point area between hounds and base.

Yes Gary, Tank you for your fast replay.
Three shrouds means that the longest free mast section is in the 2 meter range right?
My cat will be trailerable then the mast weight is a major concern... I think if I can pass from one to two diamonds, to reduce the unsupported lenght...
another problem is to trailer the mast it would be useful to split it in two sections...
But I don't see any reliable and light joint for that type of mast...
Do you have any suggestion?

Paolo

[Gary Baigent]

Paolo, Forget about breaking the mast down into two sections; the joint will be tricky to engineer and to build - and also heavy. A 10 metre mast is not difficult to transport, leave it complete. Also being only 10 m, if you build a reasonably thick section wing, like Harry's at .450 x 140mm or 150mm, you won't need spreaders - that also will make it easily trailered. Use carbon instead of wire.
cheers Gary

[Boston]

nice boat Gary

[jpquattro]

Paolo, Forget about breaking the mast down into two sections; the joint will be tricky to engineer and to build - and also heavy. A 10 metre mast is not difficult to transport, leave it complete. Also being only 10 m, if you build a reasonably thick section wing, like Harry's at .450 x 140mm or 150mm, you won't need spreaders - that also will make it easily trailered. Use carbon instead of wire.
cheers Gary

mmmhh I know...
I can have a joint light, simple, reliable: pick any two...:) :)
About the single piece stick we, here, have strange laws.
The one related to this problem is: the trailer's load cannot extend over the car... This means that the mast must ang after the boat a couple of meter with a plate with red and yellow stripes... dangerous for road users and for the mast...

about the carbon reinforcement I have a theory... maybe is better to open a separate thread on this...

Paolo

[jamez]

mmmhh I know...
I can have a joint light, simple, reliable: pick any two...:) :)
About the single piece stick we, here, have strange laws.
The one related to this problem is: the trailer's load cannot extend over the car... This means that the mast must ang after the boat a couple of meter with a plate with red and yellow stripes... dangerous for road users and for the mast...

about the carbon reinforcement I have a theory... maybe is better to open a separate thread on this...

Paolo

Hi Paolo, glad to hear your SF 26 is nearing completion. possible alternative.. a 9 metre mast with a big square top main and a high forestay attachment?? Or maybe a long drawbar on the trailer to accomodate the mast length. Most Ts's seem to cope with a bit of mast overhang but I can understand your apprehension about it.

[jpquattro]

Hi Paolo, glad to hear your SF 26 is nearing completion. possible alternative.. a 9 metre mast with a big square top main and a high forestay attachment??
....

Hi Jaimez, maybe that You tink to another Paolo, I am building one heavily altered cat 254 from Paul Fisher
http://www.selway-fisher.com/YachtCats.htm
But the original has been altered so heavily that Fisher would deny the paternity :D
I was also thinking to the use of a wharram main, but I don't have any definite replay to the main question: how it performs windward?

Paolo

[village idiot]

You talking to me, jpquattro? Guess you are since Flash Harry's mast is thin skinned. Three shrouds, no spreaders - but there are a number of layers of carbon run and spread over the halfway point area between hounds and base. FH is a light boat, around A Class weight, and the mast is actually 25 years old and has never broken, yet has been in some horrible sailing conditions, when my heart was in my mouth.

Looks good ,can you explain the steps and materials needed to build a mast such as this? I starting to realise there are dozons of ways to build wing mast ,I'm trying to work out the easiest way with the best results possible(strength / weight /cost.)

[Gary Baigent]

Strip planking in 5 or 6mm paulownia, cedar, balsa, or dense foams using half female moulds is one way, and although it is a picky, sticky time consuming method, the results, once faired, look very good. Laminate in combinations of box weave glass inside and outside with uni directional carbon at bending and high load areas also on the outside. Have an I beam of foam and glass or diagonally cut 4m ply running up the thick section of the mast - but this is not always necessary, depends on weight of boat. Glue the two halves together against the I beam then glass the seam joints. I like uni carbon for extra stiffness in the below hounds area - and also lower stays attached halfway between hounds and mast base (similar to the main hounds shroud attachment) that is, to the leading edge of the mast. That means you don't need diamonds, mast is clean. The trailing edge for the main luff on Flash Harry is 10mm alloy tube, base roughened and glued to squared off trailing edge of mast - then lay glass tape over the glue join.
The other way for the non professional unable to pay a fortune to boat builders is to use tension ply. And this is a quicker method - and the results can be excellent IMO. Get the Gougeons' book. Explaining it all here is a very boring read. In short: Mast length I beam glassed both sides - cut frames in 4mm ply or glassed foam, cut out areas for halyards to run, also cuts weight, now cut frames at thickest section, glue these to I beam, there's your skeleton. Glue two lengths of thin wood to trailing and leading edges of skeleton, that's the bases for 3 mm ply attachment (leading edge) and alloy bolt rope tube for sail (trailing edge). Skin with 3 mm ply, or lighter aircraft ply if you can afford it. You can do this in the 2.4m ply length sections by carefully lining up the scarphs, glue and staple. Staple gun and lots of clamps are essential. Was that a bloody boring description or not?

[jamez]

Hi Jaimez, maybe that You tink to another Paolo, I am building one heavily altered cat 254 from Paul Fisher
http://www.selway-fisher.com/YachtCats.htm
But the original has been altered so heavily that Fisher would deny the paternity :D
I was also thinking to the use of a wharram main, but I don't have any definite replay to the main question: how it performs windward?

Paolo

Confusion is certainly possible :) :confused: :)

The Paolo I'm thinking of used to post as 'Zini' on another site building the same boat as you.

cheers

[jpquattro]

Confusion is certainly possible :) :confused: :)

The Paolo I'm thinking of used to post as 'Zini' on another site building the same boat as you.

cheers

I am Paolo Zini.
Now I have realized where I have read your posts...:)

Just retired, but I have less spare time than before :(
I am a slow builder, but I hope to finish now or then...

Paolo

[village idiot]

Was that a bloody boring description or not?

no not really ,thats more or less what I had in mind:rolleyes: :cool:

[ThomD]

I'm wondering a bit how much carbon has to be a part of the picture in cruising quality wooden aero sections, or wings? The Gougeons were into a 3-1 size spar with carbon re-enforcements, but they also made some rather low tech spars at times. Resawn 2x4s etc... Of course if one is out to win races carbon is probably necesarry. But what about the Jarcat spar a 2x4 on edge with 1/16 aero ply fairing; Gold coast 2-1 strip; Newick wooden strip. Some of these may have had carbon in them too. It can be a closed mouth field and so what is in all these little darlings can be a mystery. I would really like to know what is in the Jarcat spar other than the wood. Anyone know?

I'm heavily into wood and archery. The highest tech bows of the late 70s can probably be outshot by hickory bows of today (fiber performance wise). This does raise the question what if some better wood ideas were used, and some tougher species of wood were used in the Ibeams of these spars?

I am of the view that short of going somewhere pretty complicated with machined parts (I own a machine shop, and am put off by the thought of the parts required...) that the best bet for trailering as in Zini's case is a separate rig to a performance rig that one might use off a mooring for club racing. I get enjoyable speed out of my blown out hobie rig on my little tri, but even that rig is hard to raise. The option I am currently pondering is something more like this:

http://www.ikarus342000.com/KD650page.htm

I know the Gunter has it's problems but if this one worked it would be good for the road.

[village idiot]

I'm wondering a bit how much carbon has to be a part of the picture in cruising quality wooden aero sections, or wings? The Gougeons were into a 3-1 size spar with carbon re-enforcements, but they also made some rather low tech spars at times. Resawn 2x4s etc... Of course if one is out to win races carbon is probably necesarry. But what about the Jarcat spar a 2x4 on edge with 1/16 aero ply fairing; Gold coast 2-1 strip; Newick wooden strip. Some of these may have had carbon in them too. It can be a closed mouth field and so what is in all these little darlings can be a mystery. I would really like to know what is in the Jarcat spar other than the wood. Anyone know?

I'm heavily into wood and archery. The highest tech bows of the late 70s can probably be outshot by hickory bows of today (fiber performance wise). This does raise the question what if some better wood ideas were used, and some tougher species of wood were used in the Ibeams of these spars?

I am of the view that short of going somewhere pretty complicated with machined parts (I own a machine shop, and am put off by the thought of the parts required...) that the best bet for trailering as in Zini's case is a separate rig to a performance rig that one might use off a mooring for club racing. I get enjoyable speed out of my blown out hobie rig on my little tri, but even that rig is hard to raise. The option I am currently pondering is something more like this:

http://www.ikarus342000.com/KD650page.htm

I know the Gunter has it's problems but if this one worked it would be good for the road.

Not to sure about the gunter rig ,the only advantage I can see is if you live on a canal or something and have a bridge you need to get under to get to open water.

Problem occurs when you need to reef the sail in a blow,the gaff works best when its up tight against the mast .the sail is cut to this shape so to reef the sail you have to drop the gaff halyard to reduce the sail area ,the gaff now is not hard up against the mast and flaps around so you can't get any leech tension as the gaff is not locked in.
Also the highest point you can run a spinnaker/screecher halyard is to the top of the mast ,you can't hang any thing off the gaff.because of the above.

:idea: One possible way around this would be to have a track up the back of the mast which the gaff would lock into at the attachment point of the gaff halyard to keep it hard up against the mast so the gaff would lock into the mast vertically any slide up and down !:confused:

A standard gaff rig dosn't seem to matter when you reef, as the gaff is always at 45 degrees to the mast whilst the sail is up,when you reef you just drop the gaff halyard down to the reefing point lines up on the boom.

A single lenght mast is much less complicated ,I would say easier to build and lighter with less moving parts

[jpquattro]

My idea of trailerable means that it can be assembled by the crew without any help but the boat and the trailer...
Drive to the slipway assemble the boat and go.

To do this the weight is the most important point, the lighter is any part to be moved, the simpler the job.
This is the reason that direct me on carbon direction, nothing else.
One 15 Kg mast is easy to rig, even by a reduced crew, one 50 Kg mast requires a crane...

If I find a way to get a reliable mast built from paper that weight 15 - 20 Kg I am happy...

Paolo

[Windmaster]

You're just tinkering around with old technology.

How about a self trimming wingsail?

A wingmast is non-user friendly since you can't really feather it.
(Remember Bullimore)

Check the website on http://www.sailwings.net

[jpquattro]

I was talking with a friend at the club bar, my friend owns one monohull, a first 211, him uses the boat mainly for local and club regatta, nothing special, but competition is competition.
We talked also of wing mast, only a bar talk, not a real project...
But the boat (remember is a monohull) is narrow, it has two shrouds order, spreaders and a bridge stepped mast.
Retrofit with a single shroud order, with a so narrow base? No way...
Unstayed mast? Too invasive retrofit, no way...

Only one excuse for another beer...
But wat about one partially stayed mast?
I mean the mast can be deck stepped on the classical ball and supported only by the low order shrouds, the sections must be the sections of one unstayed mast obviously...
There is also the forestay problem, what about running backstay?

Paolo

[village idiot]

bump...