Category: Our Catamaran Build Kits
Technical Information
Technical Information
The Technical Information page is a collection of documents (mostly in PDF format) on the materials and systems used in Schionning catamarans. Including data sheets, engineering information, strength comparisons of each core material and informative articles from Jeff outling the design of certain system such as engine choices and main sheet systems.
Detailed engineering data
for your research!
We understand that getting your head around the process of building your own boat, or having one built, can take a little while. To gain a greater understanding of the materials used in our designs, the below data sheets have been supplied by ATL Composites, and contain all of the technical data you could need regarding the composites we use. In addition are articles or documents written by Jeff about certain systems used on our designs and why.
Documents library
- Mainsheet Systems for Catamarans
- Motor Choices for Schionning Designs
- Weight and Weight Distribution Schionning Designs
- Schionning Designs Sailing Performance and Tips
- Hull Shapes and Performance – Power Designs
- Outboard Engines VS Diesels – Written by Ross McCombe
- An Outboard Installation That Works – Ross McCombe Follow up
Kit Materials Contents
kit materials' Contents
So if you order a Schionning kit, what exactly is going to arrive? See an overview of the materials you will receive, and what each is used for during the build process. Fibreglass cloth or tapes? Microspheres, Microballoons or Microfibers? Take a closer look and you can answer these questions.
Our Schionning Kits are a no nonsense, common-sense approach to building a boat. We offer great service, fast delivery and access to anything you could need for your boat straight from the supplier to your door. Our construction plans and kits are sold with 100% professional boatbuilder support via phone and email, any time you're unsure or just need a second opinion, we're here.
Our kits contain all of your basic materials to build your boat to a faired shell stage, ready for painting and fit-out. We have sail-away costing estimates available for all of our standard designs, and this will give you an accurate idea of the overall cost of your project. This costing varies depending on your level of finish, as you can imagine different options vary greatly in price.
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.
What do I actually receive?
DUFLEX PRE-LAMINATED PANELS
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.
KINETIX LAMINATING RESIN & HARDENER
Kinetix Laminating resin is used on all of our designs and is used for laminating the strip-planked areas, so round-bilge designs will use it more often whereas our flat panel designs not as much.
The reason we use Kinetix is that it has a much higher heat resistance than West System epoxies and for larger surface areas that will be in direct sunlight it is the safest solution.
The Kinetix resins are mixed by weight/volume at a mixing ratio of 4:1.
WEST SYSTEM EPOXY RESINS
The West System range is the most widely used composite epoxy system in Australia and the World when it comes to marine applications. Trusted and recommended across the globe, these products are used for most of the gluing applications involved in your build. Pumps are sold for mixing the resin and hardeners, at a ratio of 5:1. The pumps ensure that 1:1 pump ratio will equate to exactly 5:1 resin to hardener. West System hardeners come in a variety of drying speeds from Fast to Slow and everything in between. This is important when certain jobs require more or less drying time, or when working in different environments and temperatures. The West System fillers are Microlight, Microfibres and Microspheres and these are used for either fairing, gluing, filling or coving in corners etc. These powders are mixed with the resin and hardener to form a putty of desired viscosity.
FIBREGLASS TAPES (DOUBLE BIAS)
These double bias fibreglass tape rolls are used for the joining of panels in our flat panel designs, or in round-bilge designs to a lesser extent.
Anywhere that DuFlex panels need to be joined, tapes will be used.
The smaller rolls come in different widths for ease of use and to save time on cutting larger rolls of cloth.
CARBON FIBRE CLOTH
Carbon fibre is used on a number of our Schionning Catamaran Designs and can be incorporated into any design to save on weight and increase the performance capabilities.
Carbon comes in unidrectional and double bias, however is much more expensive than standard fibreglass (as one might expect). It is very similar to work with, however the resin choice may change when using carbon.
FIBREGLASS CLOTH
Fibreglass cloth is the strength and stiffness that holds your boat together, this is used in most areas for strength and is used in a variety of techniques depending on the area or job that is being performed.
Fibreglass is one of the most widely used materials for low weight and high strength properties.
The Kit Process
The Kit Process
Building your own boat can be a daunting prospect, however to demonstrate each step in the kit assembly process, we've created this guide for you to study. As you can see our kits are the ultimate in building efficiency and have been streamlined over 30+ years to ensure that you're on the water faster and with less effort.
How does it all go together?
STEP 1
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.
STEP 2
Once you have released the pre-cut frame panels, they are erected along the strongback in sequence. The hull panels will be laid over this framework to form our hull shape.
STEP 3
Here we can see the hull has now been taped and glassed, ready for turning soon. Once this has been completed the hull will need to be rolled over and the process repeated to produce the second hull. The use of flat panel construction techniques and the time-saving element of pre-cut kits really becomes noticeable. Having this head start is invaluable and could save almost 1000 hours on your build. (Wilderness 1100 design shown.)
STEP 4
The fairing is now complete, this is done using a filler compound mixed with our West System epoxy resin and applied to the surface of the hull. This process is to ensure that when painted the boat will have a smooth and glossy appearance, and as a general rule the more painstaking the paint-job and fit-out, the higher your resale value.
STEP 5
Now comes the turning of the hull! There are many different ways to do this, some involve cranes or complex equipment, however the smaller designs can simply be turned with a few extra pairs of hands, or a block/pulley set-up. Once both hulls are turned the tops of the bulkheads will be used to join the two hulls, and then the bridgedeck component will be installed underneath.
STEP 6
The hull now turned, the second must be positioned and aligned before the large bulkhead panels are used to fix these together. Once this is complete, she will start to look like a catamaran!
STEP 7
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.
STEP 8
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.
STEP 9
The internal furniture is now installed, if you chose Kit Option 2, this furniture will be pre-cut to your previously decided upon layout. If you chose to receive blank panels, this is the period in which your internal living areas are to be built. This construction uses paper-honeycomb Duflex panels, as these are superior in weight when used non-structurally. Cabin soles, engines and daggerboard cases are also now installed.
STEP 10
The transoms and cockpit area are now completed, along with the targa bar, if you’ve chosen this option.
STEP 11
The next step is our hull-to-deck joins, side decks and close the shell. As you can see strip planking methods are used here to ensure a pleasing design to the eye. This technique is not difficult and the planks are once again glassed in place to ensure again stiffness and strength.
STEP 12
The cabin roof will have been built seperately from the boat, and dropped onto the bulkheads when needed. The cabin sides are then installed and we have a cabin. The next step is to carefully mark our window lines and get cutting.
STEP 13
Cutting of hatches, portlights and your saloon windows is now done, edges must be cored. Interior and exterior painting can now be completed after fairing.
STEP 14
Fairing is now completed and your final finish needs to be achieved. How extravagant you want to get with paint choices and decals is up to the owner and the project budget.
STEP 15
Fairing is finished up and the shell is ready for painting. This is as far as the Schionning kit will get you – from this point on the finishing touches, rig and deck hardware, equipment and appliances must be installed along with finishes such as carpet, roof linings etc. We can supply you with a rough sail away estimate based on other finished projects of a similar size when enquiring about a design, so don’t hesitate to email us if you’d like to investigate further, the build process can take a while to get your head around and we certainly understand that.
STEP 16
Once installation of major systems and finish has been completed the boat can be launched. Again this is something that should be planned beforehand however our designs can safely be loaded onto a flatbed semi-trailer sitting solely on their bridgedeck without any problems. So as long as you’re within a reasonable distance, a simple truck hire should be sufficient for your launch.
STEP 17
Once the mast is stepped, its time to go sailing!
THE LAUNCH
Building your own boat is a rewarding experience and you’ve built a valuable asset on which you can make a considerable profit. If you have any questions regarding build options or designs, please contact us by email, or via the contact page.
Material Choices
schionning Material Choices
solutions that work best for catamarans & why?
Our designs are based on cored composite construction techniques using West System epoxy resin and knitted fabrics. But given the range of today's composite technologies, which solution works best for catamarans and why? Written by Jeff Schionning
SELECTING THE CORRECT MATERIALS
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:
- End-Grain Balsa – 150kg per cubic metre
- Superlight Balsa – 94kg per cubic metre
- Western Red Cedar – 360-380kg per cubic metre
- Foam – 80kg per cubic metre
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.
- Initially one would expect this cat shell to be lighter as it is ½ the weight of Balsa. We do have to compensate for its weaknesses and will then add to the reinforcement the reinforcement on the outside to spread that compression load over more core and need a triaxial type weave to compensate for the veneer content that runs fore and aft on the Durakore.
- Secondly, we need to increase the Core thickness to compensate for the shear value, usually neutralizing the weight advantage.
- We only use structural foam core that is closed-cell and cross-linked.
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.
Secondary Issues
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!