Circumnavigation w/o liferaft

[Steve Rust]

Lodesman
My source had it atributed to Lincoln but now that you mention it it does sound like something Mark Twain would say.

[BigCat]

The viscosity figure is probably CPS, centerpoise. My fire-resistant vinylester Dion 9300 has the same viscosity. I have seen resins rated as low as 150 and as high as 3500. To those wondering how this relates to liferafts, it goes back to my suggestion to use fire-resistant resin, to make your boat into a more reliable alternative to a liferaft, as fire is one reason for abandoning ship. Fastcat raised objections to using fire-resistant resins based on lightness / strength / price, and Alan is refuting part of his argument regarding this. I STILL have not seen strength figures for the resin Fastcat is using, and feel that it remains to be seen that his epoxy is greatly stronger than my vinylester resin, based on figures I have seen for commonly used boat epoxy resins and comparing them to the figures for my vinylester--this issue is very relevant to the question of whether or not to use fire-resistant resins. **** **** **** **** **** **** **** **** I do grant, however, that Fastcat's goals for lightness exceed my own, as I will settle for a laminate only moderately lighter / stronger than average for stock cats, and Fastcat is seeking the strongest / lightest available at any cost short of using an all carbon fiber layup. Comparing laminate lay-up weights won't really work, because my project is a much larger boat than he is using for his figures. Another unknown is how much framing he is using. I am using very little, and framing actually weighs quite a lot, due to the need for large overlaps of laminate onto the shell at each reinforcement.

[David_Old_Jersey]

Originally Posted by Steve Rust

The boats coming apart does not seem to be a problem from several incidents I have read about.

I do not doubt this, my post was more a caution about always assuming that in all circumstances this will be true - when deciding liferaft or not. Quite probably the odds are that this will be the case. But nothing is ever 100% certain in practice, no matter what the theory (or Brochure?) says.

and FWIW I too would try and stay on (in / under?!) an upturned Multi for as long as feasible rather than taking to a liferaft (if I had one ) for the reasons given.

[BigCat]

In fact, based on these figures, my vinylester is stronger than MAS or West epoxies, and they are hardly off-brand resins: http://www.reichhold.com/docs/bullet...0FR%209300.pdf Epoxy - MAS Epoxies: Infusion Resin - Fiberglass Resins, Hardeners, Glues, Adhesives - Repair and Build Boats & Other Marine, Repair Cars & Automotive, Do Woodworking, Sport & Recreation, and other applications WEST SYSTEM Epoxy Physical Properties So, I see not reason not to go with strong, corrosion resistant, fire-resistant, and relatively inexpensive vinylester resin versus flamable epoxy.

[Alan Wheeler]

There are a few comments made over the course of this thread, that are obviously biased. That's OK, nothing wrong with that, but it is silly to believe one hull type is better than another. Multi hulls sink and break up, that's a fact. Mono hulls sink and break up, fact too. Mono's can also return to upright after being severaly rolled over or pitchpoled and can still be a dry comfortable home to get the crew to safety, just as much as a multi can by remaining afloat. There are good and bad points with both and that needs to be accepted. I can tell you all some very negative stories about multi's, but for what result. I am sure there are as many negative stories about Mono's you multi boy's could throw back. Nobody wins. You each choose the hull for how you want to sail. But one thing is certainly for sure, you are a fool to believe that you are bullet proof in a multi and so not take a liferaft. However, in either Multi or Mono, if the situation is bad enough to cause you to abandon ship to the liferaft, chances are, it will be a death sentance anyway.
I would so love to have the speed of a multi. There are a couple here in my waters and they leave me standing. My wife wants one because she loves the wide openess of the interior. I must say I like that too. But the first issue we have to deal with here in NZ is price. You won't find anything decent for under NZ$400K. Then they go up from there. Anything under 400K is either a day sailor(as in small, certainly not live aboard) or some nightmare waiting for a place to happen. So that rules that out for us.

On the subject of fire proofing. Even fire retardent does not stop polyester from burning. It slows it down greatly. But the real threat from fire in say the engine room is the heat and the fumes. The Fire retardent does not stop the material form producing great quantities of toxic fume and it does not stop the material from melthing if another fuel such as Diesel or similar is the actual fire.
The real differences in strength between Epoxy and Ester resins is not so easy to quantify. Strength is a combination of the composite. You can't say Epoxy is stronger, or Ester is stronger based on the testing of the Resin itself. The strength is part and parcel with the fibre layed into it.
There are certainly very big differences in layup techneques and thus the end result is reflected in price.

In fact I'd bet there isn't even any water in the main hull.

Um yep, the hulls were flooded with water. In fact they could not tip the hull back over even after they had cut away the crossbeams. So they towed the two pieces back and then pumped the water out and have flipped it over with a crane.

[fastcat435]

Good Morning Alan

You are right in saying that epoxy is not stronger than Vinyl ester just as a resin but combined it really is since it can stretch more before it breaks and therefore matches better with most fibers. When evenly matched to for instance E Glass, Carbon fiber or Basalt fiber and properly post cured
It is up to 35 % stronger than polyester or vinylester, this does not only help in added strength but also helps in minimizing weight since if a laminate is stronger weight reductions can be done by making a laminate with less fiber content and this saves both on the fiber and in the resin absorption.
We have done stress tests with laminates in vinylester, polyester and epoxy resin and in all test the epoxy came out strongest.
Another advantage is that epoxy has a very limited shrinkage and it does not give print thru so chopped strand matt can also be eliminated saving even more weight.
Because epoxy is waterproof an epoxy primer is not needed so more weight can be saved.
Our resin infused laminate on the FastCat weights 4.9 kilo's per squire meter and if we had made it in resin infused vinylester it would add at least 2 kilo's per squire meter and that is excluding 600 to 800 grams of gelcoat. ( we spray paint our cats in Awl Grip paint saving another 600 grams per meter).
The extra weight on the 435 would be 800 kilo's just by changing to vinylester excluding the gelcoat and epoxy primer.

Warm Greetings from a cold Amsterdam

Gideon

[fastcat435]

Hallo Alan

Good to hear from you
The Units used are Mpa 450 , regarding the polyester , you are stating it yourself the pressure is brought back to 60 %.
Over 60 % vacuum Pressure Styrene starts to boil even in Danmark .
It is true that less and less styrene is used due to the Kyoto protocol and it is the intention to ban Styrene altogether but i do not see how it can be done with the use of Polyester or vinylester.
The types of resin with low styrene are more expensive than the high styrene contend types and for that reason the use of epoxy will grow.
Offcourse vacuum bagging is done with the same vacuum pressure, I only state that more resin stays behind with vacuum bagging than with
Resin infusion. Even you will agree on that.
We have done tests on this and we ended up with laminates with up to 27 % extra weight.
Once you are building your Dream cat and that is a compliment you will findout that resin infusion with epoxy is the way to go.
Otherwise your cat will have much more weight than necessary and I have the feeling that you are as performance oriented and thus lightweight as I am and why would you go thru the same trial and error phase as I have done while you are free to use my experience without cost.
I am not your competitor although it looks like you think so.
If you want to be succesfull in nbuilding a lightweight performace cruising cat there are 2 ways to go in keeping it lightweight.
1.resin ifusion epoxy
2. preimpregnated fibers and stying away from gellcoat and chopped strand matt in both cases.

Both these methods give a fiber to resin contend of beter than 62 to 38 %

Warm Greetings

Gideon

[Alan Wheeler]

Warm Greetings from a cold Amsterdam

What on earth are you doing way up there.

Another major difference and in my opinion advantage of Epoxy is the ability to take impact without "shatering". Epoxy reasins that have a slight amount of flex tend to absorb shock better than Ester based resin. Ester based Resins are very brittle and an impact can result in a lot more damage. The key to reducing damage from an impact is the ability to take the stresses away from the impact area and along and through the structure. This is the key to Ferrocement. It would be a useless material if it wasn't for the one major advantage of being able to transmit the stress and shock from an impact through and along the structure. Epoxy is also very good at this. Not so much the resin, although it's elasticity helps, it is the layup that makes the difference. Being able to lay directioanl cloths means stress is transmitted along the fibre direction and absorbed into the greater hull.

[fastcat435]

Originally Posted by Alan Wheeler

What on earth are you doing way up there.

Another major difference and in my opinion advantage of Epoxy is the ability to take impact without "shatering". Epoxy reasins that have a slight amount of flex tend to absorb shock better than Ester based resin. Ester based Resins are very brittle and an impact can result in a lot more damage. The key to reducing damage from an impact is the ability to take the stresses away from the impact area and along and through the structure. This is the key to Ferrocement. It would be a useless material if it wasn't for the one major advantage of being able to transmit the stress and shock from an impact through and along the structure. Epoxy is also very good at this. Not so much the resin, although it's elasticity helps, it is the layup that makes the difference. Being able to lay directioanl cloths means stress is transmitted along the fibre direction and absorbed into the greater hull.

Hallo Alan

I live in or rather very near Amsterdam and fly out to my factory in Durban once every 6 weeks.
You are right it is better in impact resistancy.
We now have changed from glass to basalt fiber to make use of the even better strength of basalt compared with E glass and these is a big bonusin this. As you know epoxy resin after being postcured becomes very hard and transmit noise very well , basalt fiber is a very good noise dampening material. so it makes our Cats more Quiet than before.
Since you are very interested in construction materials I can send you specs on this fantastic fiber
My mail address is gideon@africancats.com
Since it not used a lot in yacht building we have it it woven for our company in Germany in 4 diffrent weights and 2 different weaves
Uni directional for attaching the hull to the deck , ( this is also done with resin infusion )
and 300 / 500 / 800 and 1050 gramms triaxial and quadraxial.

It attaches even better to epoxy than glas or carbon
And I am very glad we have found this material to produce our cats with.

Greetings

Gideon

[Alan Wheeler]

Please feel free to post some description here, I think this would make great reading to us all. I have never heard of Basalt fibre.

[fastcat435]

Originally Posted by Alan Wheeler

Please feel free to post some description here, I think this would make great reading to us all. I have never heard of Basalt fibre.

Hallo Alan

I have placed the info in a new Tread called
"Basalt fiber yacht production"
Construction, Maintenance & Refit

since it is also informative for monohull sailors
I have got more info but all in PDF that exceed the attachment space of 400 KB

Greetings

Gideon

[Nordic cat]

Originally Posted by fastcat435

Hallo Alan

Good to hear from you
The Units used are Mpa 450 , regarding the polyester , you are stating it yourself the pressure is brought back to 60 %.

Over 60 % vacuum Pressure Styrene starts to boil even in Danmark .
Offcourse vacuum bagging is done with the same vacuum pressure, I only state that more resin stays behind with vacuum bagging than with
Resin infusion. Even you will agree on that.
We have done tests on this and we ended up with laminates with up to 27 % extra weight.
Once you are building your Dream cat and that is a compliment you will findout that resin infusion with epoxy is the way to go.
Otherwise your cat will have much more weight than necessary and I have the feeling that you are as performance oriented and thus lightweight as I am and why would you go thru the same trial and error phase as I have done while you are free to use my experience without cost.
I am not your competitor although it looks like you think so.
If you want to be succesfull in nbuilding a lightweight performace cruising cat there are 2 ways to go in keeping it lightweight.
1.resin ifusion epoxy
2. preimpregnated fibers and stying away from gellcoat and chopped strand matt in both cases.

Both these methods give a fiber to resin contend of beter than 62 to 38 %

Warm Greetings

Gideon

Hi Gideon,

Not to be a nitpicker, but the viscosity is probably in centipoise, Mpa (megapascal is pressure/force) See here: From Wikipedia.

The poise is often used with the metric prefix centi-. A centipoise is one millipascal-second (mPa·s) in SI units. (1 cP = 10-2P = 10-3 Pa·s) Centipoise is properly abbreviated cP, but the alternate abbreviations cps and cPs are also commonly seen.
Water has a viscosity of 0.0089 poise at 25 °C, or 1 centipoise at 20 °C.

Regarding vaccum levels, as stated earlier,you can infuse at 80%, but bring it down to 60% before it goes "off".

I agree with you, that to achieve the lightest possible construction, resin infusion or pre-preg is the way to go.

When building a single boat, the price for the moulds are exorbitant, so the "poor mans option" is to go with vacuum bagging using plugs. If this is done by a good crew, you can get to within 5%-10% more resin than infusion, totally on my boat at 47 ft. this will mean around 200 kgs max, out of the 2300 the empty boat will weigh (but with all structures in place).

I have done alot of work in the wind turbine blade industry, and still do, and have had these figures verified by a couple of very knowledgeable people, who do nothing else.

This is also based on the yards past proven performance. 200/2300 is under 9%. So the 27% you claim sounds a bit high.

I will be using epoxy due to the reasons stated by Wheels above, and will pay the higher price.

Gideon, I am not your competitor, and never will be. I just react to claims/statements that I feel are not factual.

All the best from Denmark, that is probably just as miserable as the lovely city of Amsterdam.

Alan

[fastcat435]

Hallo Alan

I understand that building a one of to start with does not pay for to build to build A female mould.
However you are probably not aware that even with a male mould or better just with the disposable stations you can build a very light weight infused yacht.
We do this standard and from this build boat we take a mould when we are finished and happy.
This is how it works.

You set up your stations on a hardback , preferably stations that are 400 mm apart.
On these stations you gleu your closed cell foam together.
If you order from Diab they can make you a kit from your drawings with the exact shapes of the pieces of foam so they fit like a wel constructed puzzle.
After all the foam is in place and airtight from the inside out and again this is very well doable, you put on your layup of glass or whatever fiber you will be using and after that you put on the perforated plastic , the flow netting in case you have used plain foam without channels, I would advise you to use the foam channeling I designed for Diab called Z 48
channels of 20 x 20 mm 1 mm wide 2 mm on both side but without the penetrations each 40 mm deep because you get a much smoother surface and less sanding to do,
Now you first infuse the Outside and let it cure , in mean while you build cradles so when your boat is turned around you can place it in the cradles and you take the stations out. After the inside is clean you repeat the process on the inner hull , the same way you do the deck ,
If you need help in the process let me know , my phone cell number is
+31654908128 If you need epoxy I might be able to help you get a good price since we order 5 tons of infusion epoxy each 3 months from Germany

Greetings

Gideon

[BigCat]

Hi, Fastcat Some epoxies are stretchier than some vinylesters, but not all. I imagine that you are using the best, but since you give no details, I have to point out that what you say isn't necessarily so. Also, vinylester is also waterproof, and many builders use it in a barrier coat to prevent blisters instead of epoxy. And yes, there is less and less styrene in the US in resins, even without Kyoto, due to domestic environmental regulations. The problem with comparing laminates instead of resin samples is the lack of a uniform test that uses the same layup. Vinylester has similarities to polyester, but not enough to justify lumping them together, as it is so superior in strength, elongation, and corrosion resistance. Indeed, when discussing polyester, it would be best to specify whether discussing "iso" or "ortho." ***** ***** ***** ***** ***** My comments about fire-resistant resin are in the context of a boat that has engine rooms that are in water-tight compartments with built-in (Fireboy) fire suppression systems. The diesel tanks on this boat are not in that compartment, nor in the next, but two watertight bulkheads away from the engines, and the fuel lines have valves at the tanks. I agree that just using fire-resistant resin isn't a complete answer to fire safety.********** ***** ***** ***** ***** As far as breaking up multihulls goes, all examples I can think of are either ultra light racing boats which were built too lightly, and home-made plywood boats. I have never heard of a "midline" multihull breaking up. Has any reader of this post? ***** ***** ***** ***** *****

[fastcat435]

Originally Posted by BigCat

Hi, Fastcat Some epoxies are stretchier than some vinylesters, but not all. I imagine that you are using the best, but since you give no details, I have to point out that what you say isn't necessarily so. Also, vinylester is also waterproof, and many builders use it in a barrier coat to prevent blisters instead of epoxy. And yes, there is less and less styrene in the US in resins, even without Kyoto, due to domestic environmental regulations. The problem with comparing laminates instead of resin samples is the lack of a uniform test that uses the same layup. Vinylester has similarities to polyester, but not enough to justify lumping them together, as it is so superior in strength, elongation, and corrosion resistance. Indeed, when discussing polyester, it would be best to specify whether discussing "iso" or "ortho." ***** ***** ***** ***** ***** My comments about fire-resistant resin are in the context of a boat that has engine rooms that are in water-tight compartments with built-in (Fireboy) fire suppression systems. The diesel tanks on this boat are not in that compartment, nor in the next, but two watertight bulkheads away from the engines, and the fuel lines have valves at the tanks. I agree that just using fire-resistant resin isn't a complete answer to fire safety.********** ***** ***** ***** ***** As far as breaking up multihulls goes, all examples I can think of are either ultra light racing boats which were built too lightly, and home-made plywood boats. I have never heard of a "midline" multihull breaking up. Has any reader of this post? ***** ***** ***** ***** *****

Hallo Big Cat you are right off course not all resins are the same.
Some Vinylester are waterproof but not all. A postcured high quality epoxy is always stronger than any vinylester and you are right we use the best infusion resin made by Dow Chemical in Germany. Tye fact that styrene is still present in Vinylester is the reason for even vinylester that they are not completely waterproof , the styrene is a solvent and it evaporates out of the polyester and Vinylester .
I do know of a Cat that broke up made from polyester , a Wildcat where one keel broke of spontaniously or at least that was the story in front of Maputo in Mozambique. I do not know what happened with the cat afterwoulds.
Greetings
Gideon