Building the fastest sailboat ever !

[watermanmax]

well that is what I am wishing,
So question about fiber glassing.
I am taking a old planning hull from a old motor boat, cutting up certain pieces and then sanding the edges down all around 5-8 inches from the edge, the re-glassing the exposed edges(0nce it is in my jig and all pieces are cut to size).
I am planning on sanding it to 80 grit and putting the thicker mesh over the top, and maybe in the inside.

Has anyone done such a thing? or any advise???

[Benz]

Don't bother.
A motorboat hull will make a terrible sailboat. They only plane because the engine provides obscene amounts of power, and they only plane at speeds not possible to achieve on a sailboat without foils and all the expense and trouble that go with them.
Save your pennies and buy a sailboat that was designed to sail, and unless your pockets are bottomless, forget about going fast.

[Joh.Ghurt]

Although it's already a few years old, here's a video on how to sail really fast:
https://youtu.be/sZVIj5TUSKE

Perhaps that'll give you some ideas what already has been done and what works. That should save you some time going down dead-ends.

[rslifkin]

Originally Posted by Benz

Don't bother.
A motorboat hull will make a terrible sailboat. They only plane because the engine provides obscene amounts of power, and they only plane at speeds not possible to achieve on a sailboat without foils and all the expense and trouble that go with them.
Save your pennies and buy a sailboat that was designed to sail, and unless your pockets are bottomless, forget about going fast.

For plenty of hulls that's true, but if you can keep the build light enough (no heavy engines helps) and pick an efficient hull form that's easily driven and planes at lower speeds (there are some), I could see it working. Basically look for a light, narrow-ish hull that doesn't have a ton of power to start with (thinking old, as they were limited to less powerful engines).

With the right hull form, it should sail something like a giant dinghy with ballast. Probably still needs a big rig for enough power and would be a lot of work. But not impossible.

[Joh.Ghurt]

For sailing fast, planing hulls are totally old-school and a dead-end. These days the way to go fast is by riding on hydrofoils.

For this reason alone the whole project makes about as much sense as adding some racing-stripes and an oversized spoiler to a SUV to make the fastest car ever.

[ranger58sb]

Originally Posted by watermanmax

well that is what I am wishing,
So question about fiber glassing.
I am taking a old planning hull from a old motor boat, cutting up certain pieces and then sanding the edges down all around 5-8 inches from the edge, the re-glassing the exposed edges(0nce it is in my jig and all pieces are cut to size).
I am planning on sanding it to 80 grit and putting the thicker mesh over the top, and maybe in the inside.

Has anyone done such a thing? or any advise???

Compare all that to a Macgregor 26.

-Chris

[Chotu]

Originally Posted by watermanmax

well that is what I am wishing,
So question about fiber glassing.
I am taking a old planning hull from a old motor boat, cutting up certain pieces and then sanding the edges down all around 5-8 inches from the edge, the re-glassing the exposed edges(0nce it is in my jig and all pieces are cut to size).
I am planning on sanding it to 80 grit and putting the thicker mesh over the top, and maybe in the inside.

Has anyone done such a thing? or any advise???

I think I get what this guy is doing and it’s BRILLIANT. Environmentally sound too.

If I’m understanding this cryptic post, he’s cutting out sections of fiberglass from old flat bottomed boats and then using a jig to bend them into the shapes he needs to build a fast sailboat. He’s talking about sanding the edges and taping them together. I think. After they are in the jig.

Holy crap it’s a great idea.

But fastest sailboat ever? No way. He isn’t using a core so it’ll already be too heavy from the start, unfortunately.

Good idea overall though.

[blubaju]

Sorry, don't feed a troll!

America's Cup, Volvo etc, all stupid idiots spending billions, just get some scrap motor boat, a jig saw, white glue & there you fly

[zstine]

I think the OP question is about the joint strength. (forget the fast boat claim and help him build a boat). He suggests a 5 to 8 inch taper. But doesn't provide thickness or materials. I think(?) the recommended taper on polyester CSM (likely what the donor boat is) is 12:1 ratio. so if the thickness is 0.5 inch, a 6 inch taper sanded from the edge should be good. obviously this is not a light weight construction method. the donor boat could be cored and could be directional E glass or ...? I suggest the OP download and read the Gougeon Bros west epoxy boat building book. boatdesign.net is a good resource

[keyway]

I have always liked the idea John Marples constant camber building technique. Using cut out panels could work. Except all that butt joint,scarf joint ground down laminate unknown resin to another. I don’t think it would end well.

[watermanmax]

Originally Posted by Benz

Don't bother.
A motorboat hull will make a terrible sailboat. They only plane because the engine provides obscene amounts of power, and they only plane at speeds not possible to achieve on a sailboat without foils and all the expense and trouble that go with them.
Save your pennies and buy a sailboat that was designed to sail, and unless your pockets are bottomless, forget about going fast.

it will have foils and a kite

[watermanmax]

Originally Posted by Joh.Ghurt

For sailing fast, planing hulls are totally old-school and a dead-end. These days the way to go fast is by riding on hydrofoils.

For this reason alone the whole project makes about as much sense as adding some racing-stripes and an oversized spoiler to a SUV to make the fastest car ever.

lol..now I am putting stripes on it!!!!

[watermanmax]

Originally Posted by rslifkin

For plenty of hulls that's true, but if you can keep the build light enough (no heavy engines helps) and pick an efficient hull form that's easily driven and planes at lower speeds (there are some), I could see it working. Basically look for a light, narrow-ish hull that doesn't have a ton of power to start with (thinking old, as they were limited to less powerful engines).

With the right hull form, it should sail something like a giant dinghy with ballast. Probably still needs a big rig for enough power and would be a lot of work. But not impossible.

Thanks Lslifkin,
Already cutting up the hull to make it 30" wide (like a oversized Kayak)....also building two 10" wide pontoons (because it will be a small trimaran) I have not decided on the mast or just go straight to the kite rig.

[watermanmax]

Originally Posted by zstine

I think the OP question is about the joint strength. (forget the fast boat claim and help him build a boat). He suggests a 5 to 8 inch taper. But doesn't provide thickness or materials. I think(?) the recommended taper on polyester CSM (likely what the donor boat is) is 12:1 ratio. so if the thickness is 0.5 inch, a 6 inch taper sanded from the edge should be good. obviously this is not a light weight construction method. the donor boat could be cored and could be directional E glass or ...? I suggest the OP download and read the Gougeon Bros west epoxy boat building book. boatdesign.net is a good resource

Thank you for the calculations and Jotu...for a lil more inspiration...I went with a old motorboat because I knew the Glassing would be strong...and as far as the weight....I am trying to spread that out with the 2 outrigger pontoons...(planing, 10" wide and 6 feet long) these lil pontoons will also hold the 5 foot retractable Hydrofoils. The main fuselage will be 18 feet long and 3 feet wide. but once it is all together the width will be 19 feet for stability. I am also probably going to have the two lil pontoons a few inches lower than the main body

[Shrew]

The America's Cup was founded in 1851. Since then teams have spent millions to design (from scratch) the fastest sailboats possible.

Millionaires checkbooks and the experienced Naval Archictects haven't tried duct tape and a junker for a reason.