CSC 30 Catamaran- the coastal passage

I have a question for the guys that have already purchased plans to this Catamaran, how detailed and easy to follow are these plans, since the builder says they are intended for people with enough knowledge and background to work independently after some guidence? Are they good and easy to follow plans or not so good? Just curious.... Thanks

 

While i prefer foam there is absolutly nothing wrong with balsa core, i have recored many balsa cored hulls and decks over the last 40 years and i can honestly say i have never encounted a single one that wasnt caused by poor build practices or ignorant owners,even on boats from so called good builders. As long as you are aware of this and take all the precautions that we learned in the 60s you wont have any issues.
Steve.

 

I think the fact that so many balsa cored hulls have to be "re-cored" speaks for itself.

I have fixed balsa cored hulls that have failed for many reasons. Not all have to do with poor construction or owner negligence. I prefer cores that are not so sensitive to water. It always gets in somehow.

 

There's a couple threads in here concerning this very issue. Always best to try and keep a thread on track lest it become indistinguishable to its original poster.

 

The builder sourced the balsa pannels from a professional manufactuer, and the fact that he was having allot of reject balsa pannels did not sit very well with me either. Its nice to hear he will replace pannels but when you are in the middle of a build what a pain in the A---!

A brand new balsa core / aluminnum pipe framed 70' Maxi sailed into Honolulu one Transpac year, it never left too many structural hull problems
to sail back upwind to mainland. many delams.

Buyer beware he should inspect matt. as delivered.

With all the tecnological advances in foam (space shuttle etc.) balsa seems an antiquated/expensive way to build. Nuf Said!

 

So since this is a bare bones, quick build kind of boat, what is a faster and/or cheaper to build method than S&G plywood? Are posters here suggesting prefabbed GRP panels?

 

Plywoods quick and easy, once you get all your scarfs done, sand and a layer of glass later, your ready to go as near as I can see. Its even easier if you forget the sail rig. Inside passage is all headwind and narrow channels, rocks and current going up and smooth sailing back down. I'd use a two man parasail myself. Rigged kinda like a kite surfer, but attached to the boat..

Oh and forget anything else expensive, I think this things intended as a poor mans get away. Which it seems like it would be perfect at. I'm trying to dream up one just a tad bigger but R Woods has a scooter model you might look at.

 

Boston you seem to be enamored with plywood. I like it myself, and have built several plywood boats too, but some other posters suggested that other methods may be faster and/or cheaper I just wonder what they may be...

 

I like it for certain things and this just seems to be the perfect use for it. If someones got another material thats just as cheap strong and easy I'm sure they'll chime in. but for 20k all up, this things hard to beat. I think Richard was saying he built his first Scooter for something like 6k. Probably all ply with some paint on it. Must have worked like a charm cause he kept the design available. No sails or rigging, the ply power cat just seems like a great combo.

I'm also kinda curious to see what might be suggested. Foam core starts out with a much higher materials cost so what methodology might enable it to surpass ply would be kinda interesting to know. Dougy 3/8 marine ply can be had for ~$35 a sheet

there's a pretty good discussion on what materials might work best or cheapest going back through the thread.

Cheers
B

 

Resale and saleability gets hit in the majority of cases Vs same design in foam or strip
Also I find the additional labour and appearance in framing, so as to maintain panel stiffness, unappealing.

 

Yes, thats exactly what some of us are suggesting,for a few very good reasons, you can build full length cored grp panels with a perfect gelcoat finish very quickly and fairly inexpensivly,then assemble just the same as S&G ply and you can get to the finished hull with a high level of finish quicker if you try to achieve the same finish with plywood. Plywood will not necessarily be cheaper if you are using proper bs1088 marine plywood, if you choose to use crap ply then maybe. It seems that Bos is pretty set on wood though so its probably a moot point. It just seems to me that a lot of folks drastically underestimate the time and material cost to get a ply hull to the finished stage with a quality finish.
Steve.

 

Question:

Where can one obtain full length, cored GRP panels in the USA? The only manufacturer I am familiar with is ATL Composites in Australia, makers of DuFlex.

Is there a similar product available here?

 

I'm not sure anyone suggested crap plywood, if you read through, the very first thing we went over was upgrading the suggested material to a better grade, BS 1088 for instance. Which if your clever, can be had for something in the $75 a sheet range $43 in dougy if you buy quantity. Almost 1/3 to 1/5 what the cored panels cost for the same square footage.

If your thinking that the ply is more expensive in the long run then spill already.

I'm thinking ply, 4ozcloth and 4oz pr epoxy, fill, paint and done, ready for mechanical. Maybe get a couple coats of epoxy on the outside if your after a nice smooth finish. Whats the materials list in foam core look like ?

cheers
B

we're at a point ?
I was just trying to keep the thread on track

 

So ur talking about prefabing the panels ur self? I thought grp panels are uncored, essentially just Matt and roving?

If ur talking about prefabing foam panels like a scarab build thoug, there is no way that is cheaper or faster than ply... Lighter though...

However Boston, don't forget the cost of epoxying all that ply and paying for all that glass sheathing! A big cat like this has lots of surface area. Even if using polyester for the sheathing, and just painting not epoxying the interior, that is still a lot of material and adds to the cost...

 

This reads like you have it backwards.

The glass goes on the outside, paint on the inside, though I'd definitely epoxy the hell out of the entire boat. At a minimum, I'd epoxy the bilges (and bulkheads) inside. They will be prone to rot, if wet.

The posters do have a point about using synthetic materials, but there are plenty of plywood catamarans that do just fine over the years if carefully constructed. This means epoxy coating everywhere. It also means not a single screw up in that epoxy coating - 3 coats minimum. Looking at all the really detail oriented wood work you have done in the pictures, I'm sure you'll do just as good a job on this boat.

Here is an example of a plywood catamaran (done by cylinder molding) that was done in 1984 and still takes people out on charters every day in Hawaii.


"I stumbled upon this picture of Kamanu, my first USCG certified catamaran design. This fog is the volcano, I was told. I designed her in 1984 and she is still going out every day in Kailua-Kona, Hawaii. CM epoxy/plywood. The head is tucked in a nacelle under the mast. Always one of my favorites."

http://www.kamanu.com/