Proa hull lines, suggestions/guidance

[gonzo]

Speed will be less than with hulls that have a smooth surface. I don't know if it will be lighter than a plywood boat.

 

[Thule]

Speed will be less than with hulls that have a smooth surface. I don't know if it will be lighter than a plywood boat.

Is that because the dacron with layers of coatings weigh that much or the amount of wood frame needed to support the sailing loads will end up heavy? Primary reason for wanting to try SOF is for weight savings

 

[gonzo]

I have made SOF canoes and kayaks. They don't have the stresses of a sailing proa; particularly if you want to get high speeds. For high speeds you need a large sail area, with the corresponding large lateral resistance area ( side of hull, centerboard, etc.) These generate opposing forces on the structure. The skin on an SOF can be discounted on the structural considerations. It keeps the water out and transfers the force of the water pressure to the framing. The question is whether you can design and build the framing to be lighter than plywood boat. I don't know if you can. However, since the goal is to experiment with SOF structures, build it and try it. If it is not strong enough it will break. At that point, you analyze the failure and go back to the drawing board. That is the standard process of experimentation. As I asked you before, is the goal to build an SOF or to build the lightest possible boat?

 

[Thule]

I have made SOF canoes and kayaks. They don't have the stresses of a sailing proa; particularly if you want to get high speeds. For high speeds you need a large sail area, with the corresponding large lateral resistance area ( side of hull, centerboard, etc.) These generate opposing forces on the structure. The skin on an SOF can be discounted on the structural considerations. It keeps the water out and transfers the force of the water pressure to the framing. The question is whether you can design and build the framing to be lighter than plywood boat. I don't know if you can. However, since the goal is to experiment with SOF structures, build it and try it. If it is not strong enough it will break. At that point, you analyze the failure and go back to the drawing board. That is the standard process of experimentation. As I asked you before, is the goal to build an SOF or to build the lightest possible boat?

I think I really need to go back to the drawing board to decide what I want. I am intrigued by the proa concept and want to make one that is fast. I am also curious about skin on frame. Perhaps it is prudent to separate the two and make a proa the way of T2 or P5 and build a skin on frame with out without sail and experiment with a low stress structure. So, may be two boats on the horizon

 

[gonzo]

We all go down the rabbit hole once in a while.

 

[Robert Biegler]

I am intrigued by the proa concept and want to make one that is fast.

Is 18' a length limit imposed by storage, or by weight? If weight, does Makahiki inspire you to invest the material into length first? Have a look at David Coy's Proa Makahiki http://www.pacificproa.com/davidcoy/ and read what Rob Denney has to say about infusion: Intelligent Infusion — Harryproa https://www.harryproa.com/intelligent-infusion

Also, if you can accommodate 31', I know someone who has a proa hull built from the CLC Boats Madness kit Madness 31-foot Pacific Proa DIY Wooden Pacific Proas Sailboat Kit https://clcboats.com/products/madness-31-foot-pacific-proa, omitting the lee pod and with experimental beams that didn't work out. He has given up on the boat. Though it being in the UK is a bit of a downer for you. But I could put you in touch, if you want.

 

[Thule]

Is 18' a length limit imposed by storage, or by weight? If weight, does Makahiki inspire you to invest the material into length first? Have a look at David Coy's Proa Makahiki http://www.pacificproa.com/davidcoy/ and read what Rob Denney has to say about infusion: Intelligent Infusion — Harryproa https://www.harryproa.com/intelligent-infusion

Also, if you can accommodate 31', I know someone who has a proa hull built from the CLC Boats Madness kit Madness 31-foot Pacific Proa DIY Wooden Pacific Proas Sailboat Kit https://clcboats.com/products/madness-31-foot-pacific-proa, omitting the lee pod and with experimental beams that didn't work out. He has given up on the boat. Though it being in the UK is a bit of a downer for you. But I could put you in touch, if you want.

Hi Rob
It doesn't have to be 18 but looking to stay under 20 for space reasons. 31 is far too big since I already have a 34 cat. Harry Proa does sound good but or of my current possibilities

Thanks though and hope the project works out for someone

 

[Thule]

We all go down the rabbit hole once in a while.

Amen