As a sailor and someone just getting into welding I found this super interesting. AL seems like an interesting metal to work/weld on. Love your boats! Thanks for sharing
I really enjoyed your video, especially the insights into the construction of these sailboats. It would be great to see how the design process works for these vessels and to learn more about any upcoming plans and projects for larger sailboats. Thank you for sharing this fascinating content!
Great yachts... I'd trust these over fiberglass all day long. I think that interior is very important as well, and that there is a challenge to find a builder that respects the need for both Aluminum and great interior and window design.
Thanks for an interesting video. I own an older OVNI and it was fascinating to see how they are constructed. I should love to visit the factory. At 10.27, Luc refers to “Some of our competitors…” that build boats not entirely constructed from aluminium. I think he is referring to Allures, which have an aluminium hull and a GRP deck and transom. He mentions the rationale for this; being able to fit out the interior with an open hull, which allows for faster construction and therefore reduced cost. Luc generously doesn’t dwell on the fact that a consequence of the Allures’ design is that these boats have a seal between the deck and hull that must remain watertight for the life of the boat. However, aluminium and GRP have different degrees of stiffness and different coefficients of expansion, so a small amount of differential movement between the hull and deck assemblies is inevitable. Over time, this differential movement will fatigue the seal. Plus, (as anyone who has owned an aluminium boat will tell you), nothing sticks to aluminium forever, not even paint. So how Allures can guarantee the watertight integrity of whatever they use to glue the hull to deck for the entire life of their boats is a mystery to me.
Merci beaucoup. Very informative! Why does one boat have longitudinal stringers and the other not? Edit: to answer my own question, the plate is thicker on the boat with no stringers. 3:55 So that structure is in the plate (and hull shape). Given how widely used 6061 is with 5083 boats, hopefully they are near each other in the galvanic series. They are different alloys of Aluminum so can have different galvanic potentials, which can lead to corrosion. Edit: looks like they are considered the same galvanic potential, which is good. Suggestion: use Aluminum "molds" for no possibility of Iron transfer to the Aluminum. (I would name the molds as fixtures.) Otherwise a totally reasonable way to build production boats with the same hulls. P.S. Luc's English is 99% better than my French. In English we call the bending machine a bending brake or sheet metal brake.
I have to say, as an aluminum boat designer for the last 25 years, these hulls look pretty good, in spite of using purely cylindrical surface development, which results in straight transverse sections. Of course the straight sections are easier to fabricate and reinforse with off the shelf (sixty- something) 6061T6 Tbar or angle. The bow round is a bit ugly, but this is the result of the cylindrical develpment compromise. A bow cone of some sort would look a bit better, to my taste. The argument for not continuously welding the transverse ribs is right, but for the wrong reasons. It is true that you do not have to weld frames continuously, but this is because they are strong enough stitch welded. However, not welding them in case of Ovni is because the 6061T6 alloy looses a lot of strength after welding. And they use 6061T6 stiffeners because this material is cheaper than 5083, so they do it to lower the cost of the fabrication, not necessarily to make a better boat.
Thanks for your compliment about the design of our hulls, we appreciate it! With the long experience of our shipyard in aluminum boats, and even longer experience of our architects, we actually decided on not using fully cylindrical surface development. Instead, we use the properties of aluminum to our advantage, in order to have an additional slight curve in the opposite direction of the main curve. This creates a slight tension in the hull, and thus a more elastic and resistant hull, which is strongly desirable in blue water cruising ships like ours. That also means we use a mix of off-the-shelf aluminum profiles (where possible because of the curves of the ship) and profiles we assemble in our shipyard (cut outs from the same 5083 aluminum sheets as the skin of the hull), to perfectly shape every curve of the hull, as the resulting transverse sections aren’t exactly straight. We actually don’t use 6061T6 for any of the profiles in the shipyard (although it’s the alloy of choice in aerospace), but we prefer stronger aluminum alloys. Although, ultimately, it doesn’t really have any meaning in the strength of the resulting boat; the ISO standards we hold ourselves to take into account both the alloy used and the welding process in structural calculations. Meaning every boat should be able to handle the same pressures, whichever aluminum alloy she is made of. Of course, with a weaker alloy, it will mean a denser structure than with a stronger alloy, but the resulting hulls will withstand the same conditions. We understand the bow round can be seen as ugly by some, but it can’t exactly be called a compromise; we decided to try it on the first Ovni 400 of the new Ovni range, and carried it on for every new Ovni design since then, as this voluminous (and actually conical) shape offers very comfortable sea-keeping abilities to our sailboats; at least according to everyone sailing on board. But to each their own, there's no accounting for taste! Luc Jurien
Nice boats. Great design But as an aluminium and steel fabricator of 30 years I would like to say that when you weld a plate around the edges there is some shrinking and this gives the opportunity to introduce a little convex curvature to the transverse frames in between the chines, also as the plate bends and twists around the hull, curvature doesn't always follow the form taken by the transverse frames. I may be wrong but this opportunity to obtain a more optimal shape may not have been utilised in the Alubat range. Dennis Ganley is an example of a designer of the past who understood the full benefits of metal construction. The metal coils around the hull and doesn't always conform to the transverse frames. I am sure with cnc programming anything is possible and I invite Alubat to look into it. It would cost no more in build time as frames are now cut by cnc and it would minimise the need to pull the plate to the frames in between the chines quite as much and create a stronger more cosmetically pleasing hull that's less prone to oilcanning.
Indeed, and we have to take into account all those properties of aluminum before we even start on the design process. To do so, we anticipate how the aluminum plates will position themselves, helped by a collective 140 years experience in aluminum construction between all our architects, and 50 years for our shipyard. We don’t use the frames to force our shape of hull, we rather first design and optimize the hull itself, without any frame, in order to get the cleanest curves possible, taking into account the particularities of the material. The idea is that we could theoretically build the hull only with the plates, and still get the same shape. Then, and only then, we decide on where to put the frames, depending mostly on structural necessities. Finally, we use CNC to get the most precise shape possible, so we’re confident in the cleanliness and esthetics of the curves we designed. The thickness of the aluminum plates also tends to reduce the shrinking and other effects of the heat, and we tend to put every chance on our side : the chine is made by the edge of the upper plate, the welding line being a bit deported inwards, making for the cleanest chine possible visually, and giving us a little boost of structural integrity in this area. Finally, we actually want and strive for a bit of pulling during the assembly, as it provides some pre-stressing to our plates, increasing once again the solidity of our hulls, and giving it the exact form we designed.
Awesome. 02:08 The aluminum plates are said to be 'enriched' (alloyed ?) with Manganese. I wonder why the material isn't anodized in order to proof it against electrolytic corrosion and if that would make any difference in the outcome ?
Aluminum has a natural resistance to corrosion in salt water because it forms a thin layer of aluminum oxide over its surface when exposed to oxygen. This layer prevents further oxidation and corrosion.
@@alubatamerica Thanks for the reply ! *"Aluminum has a natural resistance to corrosion in salt water because it forms a thin layer of aluminum oxide over its surface when exposed to oxygen"* I heard that from other sources, but still wondered if additional anodizing were theoretically desirable (but maybe not feasible), creating a thicker and harder layer - it would make for fancy metal dyes, though...
Hi Gilles, we are as anxious to show it as you are to see it. The first catamaran is under construction now and the construction methodology that has worked so well over the decades will be the same on the cat.
As a sailor and someone just getting into welding I found this super interesting. AL seems like an interesting metal to work/weld on. Love your boats! Thanks for sharing
Thanks for providing a great insight onto the detailed manufacturing process - keep them coming !
very nice, keep the videos coming!
I really enjoyed your video, especially the insights into the construction of these sailboats. It would be great to see how the design process works for these vessels and to learn more about any upcoming plans and projects for larger sailboats. Thank you for sharing this fascinating content!
Interesting video. Hoping to see a bit more on the 430's construction, with a deck saloon interior.
Great yachts... I'd trust these over fiberglass all day long. I think that interior is very important as well, and that there is a challenge to find a builder that respects the need for both Aluminum and great interior and window design.
I need more info. Yes, keep them coming
Thanks for an interesting video. I own an older OVNI and it was fascinating to see how they are constructed. I should love to visit the factory.
At 10.27, Luc refers to “Some of our competitors…” that build boats not entirely constructed from aluminium. I think he is referring to Allures, which have an aluminium hull and a GRP deck and transom. He mentions the rationale for this; being able to fit out the interior with an open hull, which allows for faster construction and therefore reduced cost. Luc generously doesn’t dwell on the fact that a consequence of the Allures’ design is that these boats have a seal between the deck and hull that must remain watertight for the life of the boat. However, aluminium and GRP have different degrees of stiffness and different coefficients of expansion, so a small amount of differential movement between the hull and deck assemblies is inevitable. Over time, this differential movement will fatigue the seal. Plus, (as anyone who has owned an aluminium boat will tell you), nothing sticks to aluminium forever, not even paint. So how Allures can guarantee the watertight integrity of whatever they use to glue the hull to deck for the entire life of their boats is a mystery to me.
Your response and insights are greatly appreciated. Thank you!
That was fascinating.
Merci beaucoup. Very informative!
Why does one boat have longitudinal stringers and the other not? Edit: to answer my own question, the plate is thicker on the boat with no stringers. 3:55 So that structure is in the plate (and hull shape).
Given how widely used 6061 is with 5083 boats, hopefully they are near each other in the galvanic series. They are different alloys of Aluminum so can have different galvanic potentials, which can lead to corrosion. Edit: looks like they are considered the same galvanic potential, which is good.
Suggestion: use Aluminum "molds" for no possibility of Iron transfer to the Aluminum. (I would name the molds as fixtures.) Otherwise a totally reasonable way to build production boats with the same hulls.
P.S. Luc's English is 99% better than my French.
In English we call the bending machine a bending brake or sheet metal brake.
I have to say, as an aluminum boat designer for the last 25 years, these hulls look pretty good, in spite of using purely cylindrical surface development, which results in straight transverse sections.
Of course the straight sections are easier to fabricate and reinforse with off the shelf (sixty- something) 6061T6 Tbar or angle. The bow round is a bit ugly, but this is the result of the cylindrical develpment compromise. A bow cone of some sort would look a bit better, to my taste. The argument for not continuously welding the transverse ribs is right, but for the wrong reasons. It is true that you do not have to weld frames continuously, but this is because they are strong enough stitch welded. However, not welding them in case of Ovni is because the 6061T6 alloy looses a lot of strength after welding. And they use 6061T6 stiffeners because this material is cheaper than 5083, so they do it to lower the cost of the fabrication, not necessarily to make a better boat.
Thanks for your compliment about the design of our hulls, we appreciate it!
With the long experience of our shipyard in aluminum boats, and even longer experience of our architects, we actually decided on not using fully cylindrical surface development. Instead, we use the properties of aluminum to our advantage, in order to have an additional slight curve in the opposite direction of the main curve. This creates a slight tension in the hull, and thus a more elastic and resistant hull, which is strongly desirable in blue water cruising ships like ours. That also means we use a mix of off-the-shelf aluminum profiles (where possible because of the curves of the ship) and profiles we assemble in our shipyard (cut outs from the same 5083 aluminum sheets as the skin of the hull), to perfectly shape every curve of the hull, as the resulting transverse sections aren’t exactly straight.
We actually don’t use 6061T6 for any of the profiles in the shipyard (although it’s the alloy of choice in aerospace), but we prefer stronger aluminum alloys. Although, ultimately, it doesn’t really have any meaning in the strength of the resulting boat; the ISO standards we hold ourselves to take into account both the alloy used and the welding process in structural calculations. Meaning every boat should be able to handle the same pressures, whichever aluminum alloy she is made of. Of course, with a weaker alloy, it will mean a denser structure than with a stronger alloy, but the resulting hulls will withstand the same conditions.
We understand the bow round can be seen as ugly by some, but it can’t exactly be called a compromise; we decided to try it on the first Ovni 400 of the new Ovni range, and carried it on for every new Ovni design since then, as this voluminous (and actually conical) shape offers very comfortable sea-keeping abilities to our sailboats; at least according to everyone sailing on board. But to each their own, there's no accounting for taste!
Luc Jurien
Nice boats. Great design But as an aluminium and steel fabricator of 30 years I would like to say that when you weld a plate around the edges there is some shrinking and this gives the opportunity to introduce a little convex curvature to the transverse frames in between the chines, also as the plate bends and twists around the hull, curvature doesn't always follow the form taken by the transverse frames. I may be wrong but this opportunity to obtain a more optimal shape may not have been utilised in the Alubat range.
Dennis Ganley is an example of a designer of the past who understood the full benefits of metal construction. The metal coils around the hull and doesn't always conform to the transverse frames.
I am sure with cnc programming anything is possible and I invite Alubat to look into it. It would cost no more in build time as frames are now cut by cnc and it would minimise the need to pull the plate to the frames in between the chines quite as much and create a stronger more cosmetically pleasing hull that's less prone to oilcanning.
Indeed, and we have to take into account all those properties of aluminum before we even start on the design process. To do so, we anticipate how the aluminum plates will position themselves, helped by a collective 140 years experience in aluminum construction between all our architects, and 50 years for our shipyard. We don’t use the frames to force our shape of hull, we rather first design and optimize the hull itself, without any frame, in order to get the cleanest curves possible, taking into account the particularities of the material. The idea is that we could theoretically build the hull only with the plates, and still get the same shape. Then, and only then, we decide on where to put the frames, depending mostly on structural necessities. Finally, we use CNC to get the most precise shape possible, so we’re confident in the cleanliness and esthetics of the curves we designed.
The thickness of the aluminum plates also tends to reduce the shrinking and other effects of the heat, and we tend to put every chance on our side : the chine is made by the edge of the upper plate, the welding line being a bit deported inwards, making for the cleanest chine possible visually, and giving us a little boost of structural integrity in this area.
Finally, we actually want and strive for a bit of pulling during the assembly, as it provides some pre-stressing to our plates, increasing once again the solidity of our hulls, and giving it the exact form we designed.
I believe this is called "trying to teach your grandmother how to suck eggs".
Awesome.
02:08 The aluminum plates are said to be 'enriched' (alloyed ?) with Manganese.
I wonder why the material isn't anodized in order to proof it against electrolytic corrosion and if that would make any difference in the outcome ?
Aluminum has a natural resistance to corrosion in salt water because it forms a thin layer of aluminum oxide over its surface when exposed to oxygen. This layer prevents further oxidation and corrosion.
@@alubatamerica
Thanks for the reply !
*"Aluminum has a natural resistance to corrosion in salt water because it forms a thin layer of aluminum oxide over its surface when exposed to oxygen"*
I heard that from other sources, but still wondered if additional anodizing were theoretically desirable (but maybe not feasible), creating a thicker and harder layer - it would make for fancy metal dyes, though...
Can you get some customization of the interior? Like adding chairs instead of settee (kindof like on HR or ComPac)?
Do you offer any diesel electric hybrid motors ? Something shaft drive that can double as an alternator ?
yes, we do!
How can you swap the engine if required?
The engines can be removed through the companion way.
Are you planning to build any bigger yachts following the 370/430 line? for e.g 50-60 ish feet ?
Yes, there are plans for a larger 650!
Fascinating!
Hi Rob
Great video, if you could do the same with the body of the Ovni Cat, it will be great...
I'm in hurry to see this cat
Thanks
Gilles
Hi Gilles, we are as anxious to show it as you are to see it. The first catamaran is under construction now and the construction methodology that has worked so well over the decades will be the same on the cat.
Question boat doesn’t have a heavy keel or keel at all how does it effect the boat balance al so in heavy weather many thanks
The boat enjoys the same balance as any sailboat of the same size. The Alubat has ballast added to the hull along with the centerboard.
I don;t know if anyone can reply to this, but what kind of hull insulation do you apply? Is it polyurethane spray foam?
The hulls are first sprayed with cork and then lined with foam insulation.
🙂👍👍