Carbon topcoat / build options

[PAR]

This is a "twill" weave, which simulates carbon to a very high degree. It's just 'glass and a fraction of the price of carbon too. It's available at most major 'glass supply houses. I should add that black 'glass is just died E 'glass and has a slightly tighter weave pattern, though difficult to tell the difference unless next to real carbon. It also isn't quite a shiny as carbon, but under resin, clear top coat and some wax, again a difficult thing to notice. It's about twice the price of regular E 'glass, but a lot cheaper then carbon. Of course it has the physical properties of 'glass.

[Eric Sponberg]

Originally Posted by dcnblues

Eric,

Many thanks. Everything you say makes sense to me.

c) Could you have a quick look at the Lindahl A Class cat hull build? I'd like your opinion about a rowboat build and whether to do it as you suggest, or inverted as they do: female frames, foam strips (done like strip planking), the interior hull, then flipped and after fairing the foam, external hull. (I can add the decks later). http://lindahlcompositedesign.weebly.com/

e) That's good advice and a cool suggestion. I wasn't thinking of a different color below waterline / and or bootstripe, but now I am. Even if I just paint the boat, I'll keep that in mind.

Any tips on getting a good price on Corecell foam most appreciated. I'm starting to suspect the supply chain is limited enough that it'll be hard to beat the price at Jamestown Distributors.

For one-offs, I like to recommend male forms over female forms, and this is because with a brand new design, the first build is going to be the first time you see the hull in full perspective 3D. You can only go so far on the computer with hull shaping--you are trying to fair a 3D object on a 2D screen. In real life, you have nowhere near the fairing eye on a female shape as you do on a male shape. That is, you can judge the hull shape best, and fair the shape best, when working on a male shape. Looking into a female shape you just don't have that good a perspective to judge fairing. Mistakes that you cannot see on the computer will stay hidden on a female shape, but they will be obvious on a male shape. That is just the way the eye works, and it shows you one of the limits of computer aided design. Cost wise male and female one-off tooling are practically equivalent, so do yourself a favor and work to a male shape. You'll be glad you did.

Corecell was developed by my friend Tom Johannsen, who sold it to Gurit-SP Systems a few years ago. Gurit-SP sells Corecell through Composites One. You can go to www.gurit.com, go to marine markets, and then look for marine distributors, and you can get the addresses and contact information for Composites One. You can also go directly to www.compositesone.com.

As for consulting with a naval architect, you can see that I have had some experience with offshore rowing boats. I helped Tori Murden with the rebuild of her rowing boat American Pearl for her Transatlantic row in 1999, becoming the first American and first woman to row solo across the Atlantic. The story is on my website: http://sponbergyachtdesign.com/Americanpearl.htm.

One of Tori's rowing advisors was my good friend David Stookey, who at the time was the publisher of a magazine called Open Water Rowing. He and I shared offices in the same building in Newport. He brought me and Ted Van Dusen together to work with Tori on developing a new carbon fiber rowing boat for her Transatlantic attempt. Ted owns and builds Van Dusen Racing Shells, the top-of-the-line carbon rowing shells, and he is an active rowing competitor. Ted has built most of my carbon fiber mast designs. Between my design and his building, we thought we could give Tori the boat of a lifetime. Unfortunately, she did not have the budget for that, so she ended up rebuilding American Pearl after it was salvaged from abandonment in the ocean on her 1998 attempt. This was the Phil Morrison plywood design for The Challenge Business. I worked with Morrison to get new templates for the broken parts of the boat, and then redesigned the accommodation to suit Tori's tall frame. This redesign is what got her across the Atlantic.

If you want to PM me with more details of what you want to do, I can give you a quote for what it would take to do a design for you.

Eric

[themanshed]

I painted a 19' catamaran with basecoat top quality UV clear coat auto paint. I also added prism flakes to an intermediate coat work well because I do not keep the boat in the water. The prism flakes over a red base coat looks really cool, but hot to the touch. The paint is not as durable as say Awlgrip but I was going for the custom effect. There is even a method of "Look like Carbon" painting now.

[PAR]

I've tried the carbon look painting technique and it works, but if you know carbon, it looks fake. 99% of the people that see it will think it's carbon though.

[Landlubber]

"a thin outer fiberglass layer which can then be sanded and coated with PU makes the most sense"....well, yes and no.

the outer layer is not fibreglass, it is simply the resin (epoxy) that is used for infusion, the boat is then painted with urethane two pack (preferrably linear urethane)....this is your UV protective layer...BUT, urethane is not for permanent immersion, so do make sure that she is not left in the water any longer than is necessary to do the job.

[themanshed]

Yep I agree with Par you can only fool 99% of the people.

[PAR]

I've done the paint job and I wasn't completely satisfied with it, but it was close enough for the customer. Then again I can spot a 'glass cloth used as a cabin top without it's weave filled, compared to a canvas covering, which most can't notice, so maybe I'm just to anal.

[dcnblues]

Never apologize, PAR.