CSC 30 Catamaran- the coastal passage

Thanks I have cut the plans from the article and posted them below. I am going to start construction on one early in the new year.
And fellow user isladelobos is doing a grwat job of drawing it all up. Hes even posted hes going to do CNC files for her.
This forum has been my best find of 2015.

 

Cheers again if there anythig I can do please let me know. You can email me at gus7119@gmail.com
I did try to pm you but was unable. Cheers mate

 

As I will be constructing one of these CSC30 with some mods and helpful input by others from this site I would like to invite anyone with any ideas to add to the discussion and have your input added to the onging designs. Who knows we just may use the bear bones to make one of the best cats ever.

 

Greetings Gus and all others

I am Bob Norson, publisher of The Coastal Passage. It has been a very long time since I have posted on a forum but this thread in particular is one where I feel my input may be useful. I have no commercial interest to protect, I sell no plans anymore. My website, www.thecoastalpassage.com sells no advertising.

I have known Leon and have seen boats that he has built and sold.

I have glanced around a few pages of this large thread. Maybe I have some ideas of what I can contribute. I can also take questions if that will help, if I have time to respond.

The beams.... why the planks on the original story but box sections on the plans? Because True Blue was built with the planks but Leon knew the boat would walk over waves like a Wharram. Light weight kept the issue under control I think. He built the boat for his own use. But he reasoned that others might not be as trusting of it so prior to releasing the plans for sale he drew up the firmer beams.

I think the building method is a very important part of the deal. Leon credits Waller for the inspiration for that. There is very little in boat building that is new, just a reshuffling of others ideas.

The basic dimensions provided for panels and bulkheads gives you guys a great start and for those that are skilled mechanically, should be all you need to succeed. Those that need a step by step of everything, should reconsider building.

cheers

bob

 

Hi Bob great to have you here. And thanks for doing those plans. I was a little heated out of the gate as I had heard of Leon before. But after studying you plans and many others Leons design is exactly the same construction method you just have to know about bulk head spacing and have enough sense to study other boats to add what you like.
I posted your plans here with no modifications and with your copyright on them.
No there seems to be a number of boats, cats, around QLD built by Leon is this correct. Also hed been a boat builder for over 20yrs? I have a numberof questions I would love to hear your thoughts.
Just to let you know it seems that your plans have ignited intrest and some of us are working to complete the plans an d a great user is doing CNC files. Weve added a coach house and as I build I'll be playing with design a little.
So great to have you here and look forward to your input. Please private message me some time.
Cheers
Gus

 

Yes, Leon was building quite a few boats out of Townsville under the name of Tykaheelee boats. Not sure if i spelled that correctly. He used to advertise them in The Coastal Passage for $1000 a foot for a completed shell ready to hang outboards on and motor away. His shed was just big enough for 30 footers so that is what he normally built.

He has a very sharp sense of economy of materials and movement. I was visiting a building site for a new home for him. He was at odds with the contracted builders as they were "doing it all wrong" and he showed me what he was talking about and he was absolutely correct, however the contractor didn't appreciate his advise... Australia... tall poppies.. do not challenge authority

He built what may be his last boat for the waterway he now lives on. It is close to what you might see in Asia working as a fishing boat. Outrigger with hardly any draft and goes well with small outboard.

cheers

 

I read back on a few of the pages around page 7 or so of this thread and there are two things I would like to mention in reference to those comments.

1, Ply versus other materials and laminating full panels in other materials. There are many good ply boats sailing every ocean. The downside to them as far as i can see is that the resale value is reduced. The up side is that working in wood is already comfortable for a lot of potential builders. It can be scary taking on a whole new skill but having said that, It is what I would suggest doing. But first a note about the ply boat Leon built. When he says in his comments to "rot proof" he means to use a two part epoxy wood sealer. FGI makes a good one. I think Altex has some too. A minimum of two coats but I would do more and I would make a point to apply that sealer in a part of the day when the temperature is falling. Never in sunlight!!!! Ply can outgass. To understand what that means if you don't already know, see my website www.buildacat.com and look for the bare bones project.

building in foam instead of ply.... excellent idea and i think leon's boat would do very well with the foam. You can very easily make full sized panels in foam. You would need a long table or a good flat concrete floor. I would use 12mm/1/2inch foam of about 80kilo per square metre density or greater for the hull panels. Maybe even 10mm would do ok. I would use 800 gram on the outside and 600 gram inside of DB glass.

Then lay out your foam which can be cut up from full sheets and some scrap. Lay it out on your flat surface with a layer of visquene, black builders plastic under the foam. Fasten the foam together however you can to make a tidy seem. Screws through thin ply pieces on the underside? Sure. When that work has set, flip over your panel and remove all your fasteners and cut open the seams a little and troll in some glue mix before you laminate the side 2. Leave set in flat position for several days before you work them as epoxy can take days depending on conditions before it sets hard. Again refer to www,buildacat.com bare bones project for more details. My first attempt was far better than the commercial products I had bought earlier, cost less than half and took much less time when I factored in the grief I had making repairs to the crap I bought at first.

I would use 20mm for decks.

Polycore was mentioned and I have worked it too. Nothing wrong with it except you have to be careful not to over saturate when laminating. Too much resin on it will soak through the polyester membrane covering the cells and fill them up.

I would still use ply for bulkheads. Its hard to beat for compression loading.

I think Leon's design well warrants the use of the more expensive materials, If it cost $40,000 to build, it would still be a very cheap cat

2, I read about some knocking of Leon's boat that seemed offhand and unfair. I think his plans have given some builders the courage to go ahead where they may not have otherwise. Knocking others when you have an obvious vested interest, has a bad look.

 

Hello.

After much work take off over (I have obligations to notify the owners).
I found a little to work the model 1:10.

I modified the exterior dimensions for a good interior roominess.

The new boat deck clearance is 700mm
The new BCB is 4000mm (from 3600) (Distance between center hulls)
The LWL is the same.
The BWL is the same.
The TC is 350mm (from aprox 250 (lite more)).
The size of the sails: (A discuss if someone you think better.).
Main Q: 10000mm
Main E: 4300mm
Fore I: 9300mm
Fore J: 3200mm
Area of ​​rudder: 0.29m2
Area keel: 0.72m2

The fully loaded displacement is About 700Kg. from empty.
The Leon's design was About 550kg. emty from?

This is a modified version (a bit) of the constructive ideas of Leon's freely published by Bob (Thanks).

I created the model using the plans that I designed using simple software. and some math (Thanks Terho Halme for its publication (How to dimension a sailing catamaran.)).

This is just a model, not a real boat, but can translate to a bigest one.

Hi Bob, Thanks for sharing your knowledge about this boat, you are very successful.

 

Two more pictures.
Now we can view the final forms.

 

isladelobos WOW! Is this what youve done since you left post last time? Amazing! So are the only dimension changes you made from Leon and Bobs plans what you have listed? As it looks different from the model I made out of cardboard. And alot better also. Please keep us updated. And please post any plans you drew up as there should be no issues with copyright or anything as youve changed the original plans by more than the 10% required by law and given credit where credits due to both Bob whos a master of ideas and skills as well as Leon.
But gee WOW!

 

Very nice model. Well done.

If you are going to use foam instead of ply, set up a table and vacuum infuse the panels. The savings in resin (between 2/3 and half as much) will more than pay for the materials and the pump. The time saved by not having to fair in overlaps etc will more than make up for the table building time. Plus, you get a table smooth exterior finish and don't have to touch the resin. One or two large mixes, stick the pipe in and 40 minutes of "wow!" and "isn't is amazing" later, a perfect void free laminate with no sticky tools, clothes or floor with no dusty trimming required.

Once you master the basics, (usually one infusion, sometimes 2), it is a small step to including everything in the infusion process.

The 18m/60' hull on the Cruiser 60 (http://harryproa.com/?portfolio=harryproa-cruiser-60), including hatches, bunks, bulkheads, mast steps, windows, shelves, doors, steps etc requires no grinding, sanding or cutting of cured laminate, post infusion laminating, aligning and levelling of interior pieces or fairing. ie, all the unpleasant, sticky, dusty, hard to get at jobs are eliminated leaving the enjoyable, creative stuff. The weight, time and cost savings are large.

 

I totally agree with Rob on infusing on a table. It is not often that a technology comes along that allows for some guy in his garage to achieve almost aerospace level results without having to spend a fortune in setup costs. In fact i think it is an ideal method for the guy who only works on his project evenings and weekends because you can take your time getting all your materials set up on the table and plumbed and the bag on during the week with just a few hour here and there without having to get dirty and then shoot the thing on the weekend. It is an amazingly leisurely process. another big advantage is that there is absolutely no reason to get sucked into using epoxy for your panels. I prefer to use vinylester myself and so far have been very happy using balsa as a core. Polyester resin would be just fine also and that combined with a balsa core will yield about the lowest cost high quality panel you can get. A lot of folks are afraid of balsa as a core (although, surprisingly, in Aus a lot of cats have been built using duflex panels with balsa core) and not without good reason but it actually is a very good core and really comes into its own when used with infusion.
It is, at least where I am the most readily available core if purchased as contour (not rigid sheets) and this is what is needed to infuse. I can order it one sheet at a time or by the case and have it the next day, which means someone else can carry my inventory.
While the standard core is heavier than H80 foam the lightweight version is very close in weight, only about a pound /ft3 more.
Of course it is less expensive than foam(at least where i am).
Balsa has very good physical properties. But what makes a balsa core really a viable choice is that if you use the contour grade( individual blocks in a scrim) in conjunction with resin infusion, each block is 100% surrounded by resin isolating it from its neighbor. It is a beautiful thing to see. This means of course that leaks around poorly installed piece of deck hardware are isolated to the individual block that the bolt passes through. It is a completely different situation to that of hand laid panels of old. The only real downside now is extra weight from the resin between the blocks but you do get that, although to a lesser extent with infusion grade foam also.

Steve.

 

I have to disagree with the foam idea. Have done a few hone builds and foam is a hassle with limited space unlike ply. Plus being a carpenter I know wood. If I had room and money Id go foam but for a home build nothing beats westsystem ply. Theres been many an argument about foam ply but simply put marine ply is cheaper and easier plus the fact that you dont need such a large space as you can build hulls beams bridge dwck cabin all separately and put together like a gig saw and tape up any openings.
The argument of time saved is a mute on between ply and foam as I know I can build a ply boat much quicker by myself then I can a foam boat even with all the sanding involved.
But man hes done a cracker on the model and working on the plans. Once hes finished I'll put my 2 cents in and we'll have a complete plan for a cat 30 to 40 foot scalable by percentage for free for anyone interested in one.

 

Great job on the model ! If it was mine I'd look at a chamfer panel along the sheer to take away a bit of the slab sidedness.
I think polycore would be the way to build this.
Just my 2c

 

Kind of like one of the Beach Marine/Crowther 10m, even a raised coaming at the cockpit area side deck could tune that up & add a styling flash through the side/ window lines, the knuckle at the transition at the fore beam looks a bit big too, but looking good! Some steps at the back of the hull cabin would be good too.- oh I see the drawing has them!

Jeff.