Home Built Wing Masts

[basil]

I thought I should move my thread hi-jack questions from Marvelous Buccaneer Alternative to a more appropriate place.

So my question is; What is the best way to build at home a wing mast for a small day sailing trailerable trimaran? The question is asked because with mature age approaching the thought of lifting a tall alloy mast is a little off putting.

Oldsailor has suggested elsewhere that an alternative may be to build a shorter wing mast that would be easier to erect and have similar horsepower.

I have read on Malcolm Tennant Multihull Design site he suggests for his Redshift design using an alloy tube with stressed ply over the outside as one way to acheive a high performance mast with minimal cost. Is this the best option?

I have seen on a Scandanavian site where they strip planked two halves with carbon uni inside and out. Dosen't seem quite as simple as Tennants option but would it be lighter?

Flame away guys - let's hear your thoughts?

Bas.

 

[gonzo]

You could strip plank the forward area and use plywood for the flatter areas. A round pipe can be used for the forward part with plywood on the rest. There is also bending plywood, which would work well; specially since most of the fibers are aligned in one direction.

 

[hump101]

I built a 9m carbon wing mast by infusing a flat panel with the UD reinforcement in the right places then bending it round into the wing shape. I'd adjusted the laminate so it naturally formed the correct shape just with tape on the trailing edge. I then set it up with the trailing edge down and flowed in some resin along the edge to create an internal bond, removed the tape from the outside then vacuumed on the necessary extra layers of carbon to give the full strength (if it was full strength to start with it was too stiff to bend). By initially leaving off layers of reinforcement that covers all the skin, as opposed to local UD, when you add it after you still have a fair shape. This is quick and easy, giving a mast structure in three resin drying cycles. My mast had no internal structure, but you can add any you need when you fold it.

You could do the same thing with glass or ply included to reduce the cost, but the amount of carbon used in a small mast, compared to the manhours, makes carbon a no-brainer for me. Lighter, stronger, easier to handle, more rapid response to load, etc.

You could change the trailing edge arrangement to match whatever sail attachment you want to use (mine was sharp as another wing element was attached). If you want a flat you can infuse this in the original panel by adding a bead with the correct angle onto the table temporarily at either edge.

 

[Dan Williams]

Have you checked out the Gougeon Brothers wing mast construction?
It uses a front bullnose with ply wrapped over a ply web and held together with a track on the aft edge.

 

[upchurchmr]

Look at the W17 plans site. There is a wing mast offered free to anyone who completed the hull(s).
Somewhere I have a copy of a Gougeon designed wing mast on an Iceboat. You can probably find it on their web site under Projects.

 

[basil]

Thanks for the response so far. Plenty already to consider.

Bas.

 

[warwick]

there is some where a description by Gary how he builds his masts.

from post 803 on is a section on them.

http://www.boatdesign.net/forums/multihulls/alternative-marvelous-buccaneer-24-a-32382-54.html

 

[catsketcher]

Basil - I have never heard of a wing mast coming out lighter than an equivalent elliptical section. If I read through my old multihulls mags about Gougeon masts and such I think I will come up with the fact that they were faster but heavier. Most alloy masts are set and forget but I have known of a couple of wing masts (early Brady and Schionning wing masts ) that failed after a couple of years and are now replaced by alloy extrusions on the boats that sported them.

Invest in a better raising system perhaps or look out for a carbon stick from an 18ft skiff or similar if your tri is small enough.

cheers

Phil

 

[Richard Woods]

As always, I agree. All the wood wing masts I have seen have been incredibly heavy.

If you are only stepping the mast on a small boat then I don't see the problem

see this page, for example and check the last two photos

http://sailingcatamarans.com/index.php/articles/11-technical-articles/268-safe-mast-lowering-method

and this video

https://www.youtube.com/watch?v=1OjzcWl0h6k

It only took a few minutes to lower the mast on the F27 I sailed a couple of days ago. Normally the 60+ yr old owner does it by himself

Richard Woods of Woods Designs

www.sailingcatamarans.com

 

[teamvmg]

Here's how I did mine;

http://teamvmg.weebly.com/mast-building.html

 

[catsketcher]

Nice VMG

Great project - seems like you did a good job. Do you know how it compares to the alloy F32 mast?

cheers

Phil

 

[rcnesneg]

TeamVMG, WOW! That is one impressive carbon mast! I will definitely want to do it the same way if I ever make a carbon mast. I'm impressed! Well done!

 

[basil]

Teamvmg, catsketcher and Richard Wood,

Teanvmg, what an excellent job? I'm not sure I'd have the skills to build something like that - fabulous.

Catsketcher, I think you're correct. The idea of a discarded light skiff rig would be easier to lift up. I had been advised that reducing the height by using shorter wingmast and square topped sail would reduce the lifting weight.
But as you say the weight of a wingmast may offset the perfomance gains.

Richard, looking at the video lifting the mast on the 18 foot Srike looks more simple than I thought maybe a change of plan back to a plan mast is in order?

Everyone else thanks for your time and input.

Bas.

 

[Gary Baigent]

You blokes are perhaps all wusses. Not bragging but I'm an old joker now ... and I lift both Sid's 11.5 x 0.50 m and Groucho's 15.5 x 0.51 metre wing masts - on my own. Agreed I use a pohutukawa tree for block and tackle angle. But I do the same with 5.5m Cox's Bay'Skimmer's two 6 metre wing masts too, without a tree, just hoist them up.
And for the size of boats that they are on, the masts and rigging are probably lighter than equivalent sized alloy versions. If not lighter, then equal to.
Maybe the younger generation .... ha, ha!

 

[Richard Woods]

Nice VMG

Great project - seems like you did a good job. Do you know how it compares to the alloy F32 mast?

cheers

Phil

An alloy mast for a F32 will probably weigh 4kg/m without rigging. So 56kg, a bit less than the carbon one

I agree that boat is fantastic and with the owners skill must clean up UK multihull racing for some years to come. Will you be racing in the SW this year at all?

I also see that making the carbon mast "added 6 months to the build time of the boat"

Richard Woods of Woods Designs

www.sailingcatamarans.com