Carbon v Glass
Printed From: Yachts and Yachting Online
Category: Dinghy classes
Forum Name: Dinghy development
Forum Discription: The latest moves in the dinghy market
URL: http://www.yachtsandyachting.com/forum/forum_posts.asp?TID=1340
Printed Date: 15 Aug 25 at 4:51am
Software Version: Web Wiz Forums 9.665y - http://www.webwizforums.com
Topic: Carbon v Glass
Posted By: Chew my RS
Subject: Carbon v Glass
Date Posted: 03 Jan 06 at 12:35pm
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Happy New Year! I am doodling a 15' hiker (I know there's plenty already available) and wondered what the cost/weight difference between glass and carbon might be? Do any of you Cherubby chaps know how much weight is saved by building from carbon/foam sandwich rather than glass/foam sandwich. And what is the cost increase? Also, any thoughts on whether to go for SAN (Corecell) or PVC foam core? Cheers
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Replies:
Posted By: jeffers
Date Posted: 03 Jan 06 at 1:02pm
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Speak to some of the Phantom boys too. I believe Vandercraft have not long changed construction which means they can build a Phantom hull down to weight and one that is also durable. FWIW they have lost approximately 10kg on hull wight with this (one of the guys at my club has just 'upgraded' and he tells me that is the difference). Paul ------------- Paul ---------------------- D-Zero GBR 74 |
Posted By: russell
Date Posted: 03 Jan 06 at 3:49pm
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Phantoms changed from polyester to epoxy - the hulls are not carbon. My Vandercraft hull has 2kg correctors to bring it up to the minimum weight of 61Kg (including foils etc). I believe this is about the usual now. Carbon masts and booms were also introduced a few years ago now. The adjustable carbon rig has made a big difference to the sailability of the boat - its now a real pleasure and has opened up the weight range. Red Eye sails are also introducing a new hiking single hander, based on a smaller Phantom. Check out http://www.redeyesails.co.uk/Redeye%20Solution.htm - http://www.redeyesails.co.uk/Redeye%20Solution.htm ------------- Russell Phantom 1330 59er 090 |
Posted By: JimC
Date Posted: 03 Jan 06 at 4:35pm
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Its a bit of an "it depends" question.
What it most depends on are things like durability, dent resistance, and your own construction skills and facilities. The latter can make a big difference to cost - a pro using vacuum bagging could quite easily use half as much resin as someone who builds a boat with out paying much attention to resin/fibre ratio. As for carbon against glass, well if you are building a minimum weight hiking boat with no consideration for how much it will dent and respond to knocks then a single layer of 100gsm carbon each side of the foam will probably be stiff enough. By contrast a bash resistant polyester/glass boat might use three layers of 200gsm glass. That's several times as much resin as well as the cloth, so the actual material costs are probably not a lot different (haven't looked at prices lately I admit!) |
Posted By: swiftsolo.org
Date Posted: 03 Jan 06 at 10:09pm
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The material on the outside of the hull is there primarily for impact resistance so it is not quite as critical to use the strongest possible material. The reinforcement inside the hull is where most of the forces will be concentrated. This is where strength is most important. On the Swift Solo I'm building we use S Glass on the outside of the hull - about 30% stronger than E glass from memory. On the inside we use a carbon/ kevlar composite which is strong! and expensive. If you are considering doing something at home I would suggest that you use epoxy. It is stronger and more expensive but the main thing is that it doesn't stink like polyester. If you want something that is strong light and not too expensive I would use E glass on the outside, carbon on the inside and epoxy as your resin. ------------- Building a Swift Solo http://www.aussieswift.livesaildie.com - First Australian Swift Solo Sailing F28 Tri - family cruiser |
Posted By: I luv Wight
Date Posted: 03 Jan 06 at 10:32pm
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Weights for cherub hull:
carbon ~ 40 kg glass ~ 45-50kg ( estimated because no-one builds in glass any more) ( as JimC says, you need more glass than carbon, so the weight and time to build goes up ) If you are homebuilding, then there is some cost saving using glass. This is only a very small percentage of the overall boat cost however. For a boat builder, the cost saving on materials is negated by the extra labour. Umm... the strongest laminate should be on the outside! - if you are using foam. For timber construction ( ie that weighs nearly 5 times as much as foam ) then both skins can be lighter, because of the compression strength etc of the wood. ( because it's heavy ) For lightest weight, you could use 150g/m² carbon outside, and 60g/m² inside, over 75kg/m³ foam, epoxy prepreg - ( but that means much more work on temperature stable moulds.) Typical very light 'standard' construction would use 200g/m۔² carbon in epoxy each side of foam, maybe with extra 100g/m² glass ouside to give more impact protection. S-glass is not now readily available in UK, hence the cost is close to carbon, so it's normally only used in classes that ban carbon. rigid PVC eg airex is good linear PVC eg airex R63 is good for heat-forming curvy parts ( and has better long-term fatigue properties) corecell is somewhere between - fairly rigid, but also a bit bendy with heat. Some foams have more open cells, and soak up much more resin. |
Posted By: Chew my RS
Date Posted: 04 Jan 06 at 8:35am
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Thanks for all the advice, it's much appreciated. I suspect it will remain a paper exercise as I have no facilities (or skill!) to build the thing, but the design is intended for my local lake and so would only sail on flat water and rarely go out above a force 4. Therefore it would be unlikely to get bashed about too much, but I'd want it to survive if it did get dinged. I will/would probably opt for the 200g/m۔² carbon in epoxy each side of foam, with extra 100g/m² glass ouside. Sub 60kg would be the aim. |
Posted By: jeffers
Date Posted: 04 Jan 06 at 9:14am
Was looking at this as a replacement for my Laser (not sure I can afford it though). I am 85KG and find myself losing out because of the additional weight I carry that better boat handling etc.. cannot compensate for. Anyone have any ideas on costings yet?? Paul ------------- Paul ---------------------- D-Zero GBR 74 |
Posted By: russell
Date Posted: 04 Jan 06 at 9:35am
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The Phantom class association has a web site at: http://www.phantomclass.org.uk/ - http://www.phantomclass.org.uk/ I think there is a for sale page, although this may have moved to be on the forum now. I bought a second hand GRP boat to start with as I recall for about £2500, and then bought a new one (almost new anyway) after deciding that the Phantom is the boat for me. ------------- Russell Phantom 1330 59er 090 |
Posted By: Pabs
Date Posted: 04 Jan 06 at 1:30pm
I would buy a RS300 sounds ideal for your weight range and skill level. You also get good value for money Paul |
Posted By: fizzicist
Date Posted: 04 Jan 06 at 1:58pm
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Pabs got there first - get an RS300 - faster, more fun, cheaper and there's no arms race for the right mast/sail combination for your weight. ------------- Not all chemicals are bad. Without chemicals such as hydrogen and oxygen, for example, there would be no way to make water, a vital ingredient in beer. |
Posted By: russell
Date Posted: 04 Jan 06 at 2:22pm
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I had an RS300, kissed goodbye to my knees! I find the Phantom a much more pleasant sail and bigger fleet. I've only raced against one RS300 in the Phantom and beat him over the water, it was light winds though. ------------- Russell Phantom 1330 59er 090 |
Posted By: Calum_Reid
Date Posted: 04 Jan 06 at 2:44pm
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From my 1 sail in a 300 u dont wana be on your knees. It leaves u too imobile ------------- 
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Posted By: Pabs
Date Posted: 04 Jan 06 at 3:17pm
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My knees are good you just have to be patient and then weep the rewards. I sail with three others on a shifty pond and don’t have a problem with her on a bigger lake or the see they are a pleasure to sail |
Posted By: blaze720
Date Posted: 04 Jan 06 at 8:54pm
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As ever you just just have to try all available - all contributions here naturally hype the writers favorite !! We are no exception of course so get in contact and come along for a trial sail and/or race in a loan Blaze. At 85 kg you are an ideal weight and if you can handle a Laser you will not find the boat difficult - it just takes a bit longer to adjust technique to suit. Where do you sail ? Cheers - Mike (Blaze Class Association) http://www.blaze-sailing.org.uk/ - http://www.blaze-sailing.org.uk/ A few video clips available via home page and within the 'for sale section'
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