Carolina flare hull

I have no expertise with aluminum but it's clear that the shell plate parts must be joined in some fashion. If welding is too likely to distort the plates then they could be riveted in seam batten construction. Of course welding got its start from dissatisfaction with rivets so maybe that is not a good idea either. Maybe thinner plates laid up with epoxy just like most are built with narrow plates of plywood.

None of it really sounds all that great where there is severe spiling to be done like on a Carolina flare. If there is enough money, shaped plates can be made but that is a lot of money. I'm pretty sure some of the Rybovichs were done in aluminum but they did not have the severe flare even if they were what the original Carolina builders used as a model. I think the extreme flare of the local NC boats is an affectation anyway. Along with the rocker near the stern that most have that holds the bow high, the flare mainly helps to hide the little boats you are about to run over so you don't have to worry about them.

 

Photo gallery of an 84' "Carolina flare" boat under construction by Jarrett Bay near Beaufort, NC. http://www.jarrettbay.com/carolina-construction/custom-yachts/hull-60/60-construction-gallery/

In the tradition of Carolina custom construction, safety, durability, and the confidence that comes from both are built into your Jarrett Bay. Our method is an epoxy-composite process, generally referred to as cold molding.

Sea TrialMaterials selection is paramount. Your yacht’s bottom is sheathed in three layers of fir plywood, and the topsides with three layers of ¼” Okoume ply made from tropical hardwood. Fir is tough and impact resistant. Okoume’s ability to conform to sensuous curves and accept a high-grade finish is unequaled. Both are marine grade, meaning the veneers are glued with waterproof adhesive and there are no voids in the interior of the panels which can create hidden weaknesses. This “planking” is laid on to the mold forms and ribbands with a proprietary epoxy formula–epoxy being stronger than the wood itself once cured. The whole is sheathed in knitted fiberglass cloth, and also wet-out with epoxy. Knitted fabrics distribute stresses more equally and provide a superior resin-to-‘glass ratio than woven material. This method creates a stiff, lightweight structure that stands up to high-performance running for the long haul. http://www.jarrettbay.com/why-jarrett-bay/rugged-construction/

 

Flared Bow in Welded Aluminum

Here's a link to a Gravios boat, not sure which division of the company is doing the work but it does have some bow flare as shown in the thread.

http://www.aluminumalloyboats.com/viewtopic.php?f=6&t=4129

As to welding the strips of aluminum or plate panels required to 'strip plank' a bow of this form (?) the cost to prep, weld and finish would probably exceed the cost to form the plates/planks to reduce the welding time and effort.

English Wheeling the plates, cutting contours like the Gravios shown above (link) at the outlines of panels and leaving them 'green' when forming would probably allow most of the Carolina flared bow's form.

An easier method but perhaps less attractive in the OP's eyes, would be to plank the hull in strakes of hull material with an increasing flam so they made a close approximation of the flare sought. The reason that planks of increasing curvature (flat outlines) would be a simpler form is the weld seams running lengthwise instead of transversely makes the weld contraction and distortion more manageable when compared to butt seams if the strips were used.

Some work boat hulls achieve the bow effect of the Caroline flare by simply lining the sheer in the forward 1/3 to 1/2 of the sheer with what could be considered a 1' or 18" coaming that is simply cut to a very pronounced curve at the lower chine where it fits the sheer.

This results in an overhang that is actually a panel with pronounced flam, not flare. However, the result is almost identical; the water is deflected from the hull and the bow is pitched up dramatically if the waterline reaches this high on the hull as when the bow is buried in a wave face.

This last is a very low cost means of achieving the performance in welded metal without the forming effort implied by the hollow curves of the Caroline flare's form.



The only handy example I have is a concept sketch of a panga of developable plates; so the bow section is the only part of this image that is germane to this discussion.

I'm simply trying to illustrate the potential for a flat plank/panel to provide some hull flam at the sheer, not trying to equate the looks of the two different shapes.



Another viewpoint of the same skiff showing the potential to plank the overhang without forming.

This concept has been used by metal skiff builders in the NW for commercial fishing skiffs for along time, and while perhaps not as elegantly stylish as the Carolina flare bow, they do provide an improvement in drying out the skiff.

Cheers,
Kevin Morin
Kenai, AK

 

Looking at the photos of the 84 footer at Jarrett Bay and the Gravios boat shows the difference between the more pronounced flare in the molded plywood and aluminum versions. The aluminum boat is closer to the Rybovich originals while the molded boat has much more flare convexity but still much less that many built locally. In the extreme versions, the topsides flare becomes nearly horizontal under the deck. Jarrett Bay is about 15 miles down the ICW and I get to look in there now and again.