
Boyard Croisiere Professional Boatbuilders

Below is a quick glance at what your Schionning Kit will include and what each item is primarily used for, we hope this is helpful and if you should require more detailed information please don’t hesitate to contact our office.
DuFlex pre-laminated panels are the main and most important material used in our kits, predominantly in the flat panel designs, however they are used in Strip-planked designs also, though to a lesser extent. These panels are 2400mm x 1200mm and are CNC routed to speed up build time on our Wildernes X Series, as well as some of our power designs. For internal furniture, a paper honeycomb core is used instead of the end-grain balsa wood core that is used for main structural areas. The use of this is purely to save weight in the shell and therefore produce a faster, more responsive catamaran.
The first step to building your dream catamaran begins with a strongback – this is a square frame used to position the temporary frames that will be used to form the hull shape. This frame will be set up and must be square and accurate, a string or laser level can be used to achieve this.
The forebeam is now installed along with the striker attachment fitting, as shown above. The bridgedeck is installed shortly after and taped onto the bulkheads with webs installed, this now completes what is a quite stiff and strong platform to work on.
Now that the bridgedeck is in place, the forward webs and dash will be fitted. At this stage, all furniture and internal work begins, with the main panels left off for ease of access when working.
We use West System epoxys for their high strength and adhesive values.
It also fully protects the boat against water absorption and it can not develop the dreaded Osmosis.
We choose ATL Composite’s resin systems for their superior quality, reliability and value for money.
Having worked closely with the ATL Composites team and their products for many years, we know we can stand by their material solutions, and rely on great service should something unexpected happen.
We prefer Colan brand cloths for their quality and low resin absorption, custom made for Schionning Marine at six (6) stitches per square inch for easy wet-out and rounding corners.
This may not seem important but when working with a material for an extended period of time, the small things make all the difference.
The core choice is usually quite confusing. Cores have different capabilities and properties, and their benefits I feel are utilized fully in our catamaran designs. A quick look at their abilities:
Balsa has very good values and we can produce a shell using a very light laminate. It will be very stiff and very resilient to fatigue.
It has exceptional qualities including very high compression strength, extremely good sheer capabilities and fantastic sheer stiffness.
Compressive strength is the resistance to collapsing when pressure is applied perpendicular to the surface as when pushing directly onto the material with the point of your finger. Balsa is far stronger than Foam (80kg/cubic metre) in compression.
Balsa is also very strong in shear. This is when the core sample is held flat between your hands, one hand slid one way and the other slid the opposite way, when the core tears through the middle the core has failed in sheer. The amount of stretch you feel before the core shears is shear stiffness. To compensate for sheer weakness the core is made thicker. So 13mm Balsa may be equal in sheer to 19mm Foam.
(80 to 200 kg/m³)
There are many boats sailing that are built from foam as it’s mechanical properties are good for boat building.
The end result using foam core amounts to a very similar total boat weight. Professional builders can achieve a good result but usually use vacuum bagging and very good molds to achieve this.
Balsa can absorb water. It needs extreme neglect to rot (very unusual). Water soaks along the end grain quickly. It travels very slowly across the grain. We use balsa under the waterline especially because of it’s high compression strength for beaching etc. any core type must be sealed. Damage to all cores results in the same sort of repair. Notice a damp spot remaining when drying out to anti-foul… simply grind back the surface glass exposing the core, dry it out and re-glass – it’s that easy.
Timber cores are cheaper than Foam in most cases.
A light, high tech cat returns a far better (often 2 – 3 times) re-sale than lower tech materials. Often saving $10,000 on materials initially, loses $200,000 on re-sale – a serious reality.
Our boats can be built using Balsa, Foam or Western Red Cedar. Combine strength, stiffness, lightness and cost, with ease of use – it just makes good sense!
Owner Geo Uhrich speaks about DUET’s impressive performance and his experiences while cruising in Spain.
“We have just returned to New Zealand after spending 5 months away in Tonga and Fiji and thought I would let you know some things that have happened to us and our Cosmos 1160 called Division II. I knew that building a time proven design would have its advantages and I feel that the boat has outdone herself in performance and comfort. When we left Whangarei back in mid June for our first ever trip offshore we were unsure just how we would go. I have to say that the boat looked after us and we had no worries. We had one day on passage where it blew up to 50 knots with a constant 43/45 knots. With only the tiny storm jib up we surfed along quite happily and comfortably at 12 or so knots one hand steering with no worries. The very buoyant bows kept the decks almost dry. The rest of the passage was very uneventful and it was almost a shame to make land fall.
During our three month stay in Tonga our shallow draft allowed us several times to go and anchor closer to the beach or tucked closer in for shelter as others were more exposed to the elements. We had countless comments on the design and finish that we achieved during the build. During Regatta Vava’u we won the multi‐hull division beating the St Francis 50 quite easily due to our pointing ability and good speed, in fact passing and out pointing most of the half boats. What a great feeling!
On our passage return from Fiji to New Zealand we were almost close hauled and as we have no auto‐pilot the boat just steered herself over the very confused swell with ease with third reef and 2/3 genoa in 25/30 knots of wind sailing at around 9 knots. We could have gone faster but the comfort level was good so why get uncomfortable for the sake of another knot of speed.
We are extremely happy with all the blood sweat and tears that were shed during the build of Division II. It has been well worth it and the life aboard for our family has been fantastic. I am now back working to get ourselves ready for our trip away next year.”
Regards Dan and Amy Kellahan.
“We left ‘D’Estree Bay’ in Broome last week and are now back in Hong Kong. A friend of ours is taking her to Borneo for us where we will pick her up again to continue the trip to Hong Kong in a few weeks. We sailed her to Perth from Adelaide in late February via Esperance and Albany and left her at the Freemantle Sailing Club for a month then, in April, took just under 3 weeks to sail her to Broome via the Abrolhos, Shark Bay, Ningaloo and the Montebellos. It’s the best sailing we have ever had. The boat goes like a rocket and is comfortable and easy to sail. She is everything we hoped she would be. Our top speed has been 24 knots but there have been plenty of days loafing along at 12 – 15 knots. In flat water we can get her to do 10.5 knots upwind – faster than our Volvo 60 which winds up at about 9.5 knots on the wind.
We have sailed with two couples and there is a tonne of room and very easy watches for the overnight legs compared to our mono hull days. We are very fussy about weight and getting the sail off her promptly. The big flat head mainsail gives her overdrive! Being a light ship makes her a joy. Thanks so much for everything.
I look at the 18 metre G-Force and am dreaming of the next project!”
DAVID HARRIS
“We leave Cairns on Sat week, the 17th for the Louisiades, Attitude is sitting up in Cairns patiently waiting for us to catch up with work, and rejoin her next Monday. Testimony to how well she sails, just Michele & I sailed her up to Cairns from Brisbane, and yes, we covered the 100 odd nm in daylight, which is just fantastic when you’re doing a delivery with two people.
The numerous beautiful anchorages along the Qld coast were a pleasure to drop the pick each night, and watch the sun set after a great days sailing. Skitting along in 25 kts of wind, double reefed main & heady, we felt very comfortable in two metre swells doing 18 kts, just exhilarating, especially with just two on board!!
The delivery proved Attitude everything we set out to achieve, with our wish list dovetailing nicely into your fantastic design.I believe Attitude gives you guys the opportunity to promote the G‐Force range as a true performance cruiser, probably the best there is, not just a bare bones racer. And as you know better than most, when it comes to making these purchases, the saying “happy wife, happy life”, certainly makes that decision easier.”
Alan Larkin
“Jag is tracking very well can take your hand off the helm at any speed for minutes on end and she says on course. Did this one day in slight seas and 20 knots of wind for seven minutes at 16 knots boat speed and her course altered by 7 degrees. I am very much enjoying ‘JAG’ she is awesome. I am cruising at 16 knots using 24.4 litres per hour for both motors.”
“We just sat out a NE blow with a max of 62 Knots wind speed. We were both very impressed with the way ‘JAG’ rode this out, I have done years of boating and ‘JAG’ would have to be the best I have been on in these conditions. Our friend was anchored beside us in the same bay in his 13.5 meter heavy displacement yacht, and he was sailing all over the bay. The outcome is his boat is on the market and one guess what he is looking at.”
“I have had fifteen boats of all kinds, and ‘JAG’ is on top of the list.”