Boat Hulls

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Boat Hulls

Author	Message
FLD	FLD posted 10 Years Ago HOT Topic Details
Group: Forum Members Posts: 468, Visits: 2.7K	Following repairing a skiff recently I've been asked a couple of times about boats. Random! The skiff was grp with a foam core. Has anyone here made a boat before? I'm curious about what sort of layups / thicknesses I'll find. One of my enquiries was about experimenting with hull shapes on a powerboat so I'll guess thats a fairly robust layup!
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ChrisR	ChrisR posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 363, Visits: 3K	You'll be in for a shock on how thin some of the hulls can be, I've seen then as thin as 4mm solid CSM on a powerboat but also up to 10mm thick. There's quite a lot of info on the east coast fibreglass website on boat building, also info at Gurit and West System websites.
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The Fibreglass King	The Fibreglass King posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 69, Visits: 652	Hello FLD I have vast experience in boat building, having built Olympic class sailing dingy's to 155' Super Yachts and every thing in between, lay ups vary considerably. With many different ways of strengthening such as webbing, stringers etc.. It fully depends on the craft you are building and it's use! Kind Regards The Fibreglass King
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FLD	FLD posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 468, Visits: 2.7K	I've been asked about 2 main types. 2 man small sailing boats and small powerboats. The sailing boats dont worry me too much but the power boats do. I expect they have to be rather robust to survive large waves etc
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Dravis	Dravis posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 592, Visits: 1.9K	I have a friend I can ask about the powerboats ... he used to build racing catamarans and powerboats at a small composite firm, including kevlar/CF work ... I'll get back to you on this ... (I'm interested as well ... always fancied myself a CF powerboat, with a V8 inboard... ... ) "Sapere Aude"... Dare to KNOW! The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind... 103% of all people do not understand statistics... Do not adjust our mind, theres a fault in reality :-)
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FLD	FLD posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 468, Visits: 2.7K	That'd be really handy, thanks.
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dbcrx	dbcrx posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 46, Visits: 1.2K	The only way you'll know the layup is to either contact the manufacturer and ask them, or drill or cut into it. As mentioned above hulls vary a lot. Not just between sail and motor boats, but even two very similar motor boats the same sort of size can have very different hulls.
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Dravis	Dravis posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 592, Visits: 1.9K	Well ... I spent nearly three hours talking to my buddy about fibreglass and keclar/carbon composite powerboats ... Basically there's a lot of trial and error in the process .. ´ Both deep V-hulls and "Flat-planers" benefit from a construction with a varied thickness. with anything up to 10 layers of standard (300 - 400 gsm) chopped strand glass in the keel area, thinning out to maybe three or four at the deck interfaces. He has a limited experience with CF /Kevlar, but he pointed out that they never used pure CF for the hulls .. There has to be some measure of flex in the hulls, and good resistance to repeated impacts. longitudinal stiffness is paramount, but the hull can benefit from some sideways flexing. The number of layers and type of reinforcement depends on the boat, its construction otherwise and the intended use .. "Sapere Aude"... Dare to KNOW! The written word is the only truly efficient vehicle for transmitting a complex concept from mind to mind... 103% of all people do not understand statistics... Do not adjust our mind, theres a fault in reality :-)
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Zorongo	Zorongo posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 40, Visits: 330	You should better let us know a bit more. Mainly boat´s size (small may vary from one person to another, from 6 to 12 m ?) Max speed, as it give pressure on the hull when striking the waves and so the stresses criterion for calculations.. Type of construction, sandwich, solid, exotics, glass. Long time ago there was a thumb rule for solid hulls: 1 mm thickness per hull´s meter long. (10 m => 10 mm) Now everything is better known and understood, allowing A general use is to alternate woven roving and CSM as CSM ir resin rich and assurees a good interface between w roving Cutting a sample or drill to builld same thickness is a good starting point. Also depending on hull´s area, stresses vary a lot, from low on the sides to very high on the slamming area (where it hits the waves) Same for local stresses, specially on sandwich construction, as core may collapse and may be substitued by high density, wood or even solid..... If high spped, the hull can also hit truncks or any other floating object, and kevlar is often choosed for outer layers..... A 30 Knots 12 m boat solid laminate had about 8 mm skin with a panel size of about 1,0 x 0,5 m Panel size is vital ........... Is a wide field .......
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