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terhohalme · 01-02-2008, 11:28

Starting to build Catharsis 26, a small catamaran for Baltic sea coastal cruising. There are some pictures in gallery. The most boats here at the forum are big and for blue waters. Are there any small boat cruisers here? How do small boats get over on cruising?

Catharsis 26's LOA is 8.0 m, BOA 5.0 m and empty weight under 1000 kg. The structure is infused glass and polyester over nidacore honeycomb. Any question or comment are wellcome.

Terho

**GordMay** · 01-02-2008, 12:20

Terho's gallery is at:
http://www.cruisersforum.com/gallery...mageuser=10473

Tnflakbait · 04-02-2008, 07:53

Looks like a cool boat. Do those hulls plane?

terhohalme · 04-02-2008, 09:00

Thanks. She is designed for (fast?) cruising and good load capacity. The hulls are not ultimate slim, L/B ratio is 8.2.

Eternal question, does a sailing multihull plane? Sure she can easily reach twice the hullspeed, but is it planing? Is the boat mainly supported by hydrodynamic or hydrostatic force? Nevertheless I am expecting speeds above 14 knots. Someone would say yes, do that...

terhohalme · 22-04-2008, 07:53

Hello,

Resin infused (at last) first nidaplast (nidacore) sheets for Catharsis. Nidaplast is 10 mm thick with one layer of 850 g/m2 multiaxial 0/90 glass on both side. The laminate is quite dry and nice, panel weight is 4.3 kg/m2.

Infusion was quite easy, though building the sack is some time consuming. A simple ejector made desent vacuum (75-80%) and we made resin trap from the 5 liter tank of pressure paint gun. Resin is Reichhold Polylite 506-677 for resin infusion, 1% MEKP gives more than two hour infusion time. Wetting time over the sheet (1.2 m) is about one hour. We use flowing net and peel ply.

Just over a hundred sheet more to infuse for two catamarans...

Terho

Nordic cat · 22-04-2008, 11:56

Nice looking boat you have there Terho. I especially like the cockpit and the bimini, but the layout is also very practical,

I'm sure that there is a market for this kind of boat up here in the Baltic area.

There is a Finnish guy who built a 26 ft. Shuttleworth a few years ago, with a similar layout, but this looks more up to date.

Regards

Alan

Tropic Cat · 22-04-2008, 15:01

Quote:

Originally Posted by terhohalme

Starting to build Catharsis 26, a small catamaran for Baltic sea coastal cruising. There are some pictures in gallery. The most boats here at the forum are big and for blue waters. Are there any small boat cruisers here? How do small boats get over on cruising?Terho

I sail a small cruising cat. At 8 meters she is the smallest catamaran I've seen with twin Yanmar diesels. On the other hand, performance wise, my boat is old and slow compared to what you're building.

Photos are on my web site.

terhohalme · 23-04-2008, 07:44

Thanks, Alan

Yes, I know the guy. A long a go he was one of my students at wooden boat school... very determined and capable.

Don't know about the markets, there just isn't any new small cruising cat on production.

Rick,
What a good site you have! Catalac 8 is a classic and about two times heavier than Catharsis 26...

rob denney · 23-04-2008, 08:50

Quote:

Originally Posted by terhohalme

Hello,

Resin infused (at last) first nidaplast (nidacore) sheets for Catharsis. Nidaplast is 10 mm thick with one layer of 850 g/m2 multiaxial 0/90 glass on both side. The laminate is quite dry and nice, panel weight is 4.3 kg/m2.

Infusion was quite easy, though building the sack is some time consuming. A simple ejector made desent vacuum (75-80%) and we made resin trap from the 5 liter tank of pressure paint gun. Resin is Reichhold Polylite 506-677 for resin infusion, 1% MEKP gives more than two hour infusion time. Wetting time over the sheet (1.2 m) is about one hour. We use flowing net and peel ply.

Just over a hundred sheet more to infuse for two catamarans...

Terho

G'day,

Boat looks good. Well done.

Are you infusing each 2.4m sheet individually? How will you join them to get the full length? Are you rebating the edges using the hot iron approach on the Nidaplast site, or will you be doing a lot of bogging? How are you sealing the edges at the chines?

regards,

Rob

terhohalme · 23-04-2008, 11:24

Hi Rob,

All the hull sheets will be infused to full length on the long table. The long nida sheets are NC machined before infusion. Normal sheets (bulkheads and so) are NC machined after infusion, so far the quality is superb.

Then the long sheets are taped together in jig with -/+45 biaxial and polyester. Then we will glue all the bulkheads. The places of bulkheads are marked by small NC holes inside the hull sheets. The outside seams will be filled with vinylester bulkhead glue (similar to microspheres+resin) and then taped.

Yep, lot of filling, sanding and painting, but I used the same method with my ping-pong proa. The original idea was to glue only the nidasheets and then infuse the entire hull, but nida is too bendy for that.

Using thermoplastic characters of nida would be nice and perhaps we'll use that somewhere inside the hulls. This design was originally for plywood and we just replaced ply with nida (cheaper and lighter).

Terho

Nordic cat · 23-04-2008, 12:26

Some pictures and descriptions as you go along would be great. How do you handle the edges of the Nidacore? Don't they absorb alot of resin? Some close-ups of how you connect the panels will be good.
What are you going to make the mast out of?

Regards

Alan

terhohalme · 24-04-2008, 08:04

Resin is the cheapest material here. Absorbtion is 8 mm on average in one joint. On the edge slightly more and mixed by microballoons. No big deal.

The mast is a commom aluminium profile. Fast fittings, easy to get and reliable. A carbon rotating wing mast maybe later...

dcstrng · 05-07-2008, 10:12

Quote:

Originally Posted by terhohalme

Starting to build Catharsis 26, a small catamaran for Baltic sea coastal cruising...

Just ran across your images in the photo gallery… That is one impressive looking little Cat… I shall enjoy following your progress, because if I ever turn to multihulls, it will be a smaller one… Am currently halfway through Thomas Firth Jones’ book on multihull voyaging – one of the few multihull writers/designers (Woods, I think, being another…) who seems to be saying that with a little design caution and common sense, modest-sized multihulls can get the job done…

Anyway… good looking design… good luck!

**sandy daugherty** · 05-07-2008, 10:37

Very pleasing design. If you are going to use an aft mounted outboard, I hope you can leave room to rig a steering system for the motor.

I sailed the Aquilon 26 several years ago, loved it, and I still believe there is a market for a boat this size if it could be delivered for about the price of a Telstar Tri.

terhohalme · 03-08-2008, 07:59

Hi all,

Most of the sheets (approx. 150) for two catamarans are infused and nc-cutted. They are piled and numbered and waiting for the students to construct them up to the hulls when the school year starts.

Terho

ps. we changed her name to Catharsis 27 after redesigning the bows.