pitchpoling capricorns?

i've read an old test (1,5 years old) of the capricorn in which they state that you cannot push a capricorn as hard as a nacra or tiger with the kite up. can anybody tell me if this is still the case? i've asked (the wrong source) a nacra distributor and he claims (of course) that the capricorns are very tricky downwind.

i'd rather hear from people who currently sail the capricorn what their opinion is.

please let me know your experiences since i want to decide which F18 will replace my current nacra F18 next season.

I haven't sailed a Nacra, but I went from a Tiger to the Capricorn about four months ago and I think you can push the Cap much harder downwind than you can the Tiger. Especially in choppy seas the bows go thru the waves really nice instead of slowing the boat down each time the bows stuff.

I'm a Cap owner. In the NAs in Illinois last month, I pitched twice, once on Tuesday and once on Friday. Both times it was as we turned down at the clearing mark - once as the chute was coming up, and once just after it filled and was sheeted in prepration for a gybe. Conditions were choppy and gusty 20s in both cases. I know that every other model boat flipped in the same races, including both Nacras and Tigers. In our flips, it was over in an instant - maybe could have saved it on a Nacra 20. Both times, I was at or near the front beam for the set - weight too far forward for an aggressive turn down, but the skipper is a 20-driver who was on the Cap for the first time. He really missed those N20 bows. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

In any case - my experience so far is that the boat is no more prone to flipping than anything else I have ever been on, including the Infusion. To be fair, I have not been on an Infusion in the conditions described above, but very experienced sailors that had the new boat took a swim with me last month, so...

I'd be interested in seeing the "test" you describe. Can you post it here or post a link? I'd like to see if it is authentic or pure bunk or something in between. Anyone that was selling a boat in Illinois last month can tell you what my advice was on the beach - unless you have a three or four year old boat you'd normally be selling anyway, you should keep what you have and focus on sailing better, not hopscotch to the latest greatest. Look at Woody Cope - he had the first gen Nacra, end pole snuffer and the oldest set of sails on the course (4+ years on the jib and main?) and he was smoking everybody but the pros at one time or another. Does that mean we should all go to blown out dacron jibs? Or maybe he's paid some dues and makes good decisions, even when he's sailing out of class. <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

hi john & f180xj, thank you for your replies. regarding the test, i've attached it. it's from a UK magazine which is quite high quality. unfortunately they only have a small section on multihulls.

john it sounds like you've had a good time during the NA's!

I can't trust a review that has pictures with a main that has that many wrinkles :P

trust this one then!

www.nacraeurope.com/download.php?fileid=10

Tornado Alive recently stated in another thread in another forum (SA), that with the use of a transom foot strap and a chicken line he has never stuffed his Capricorn down wind, so they can't be that bad.

Yeah, from nacraeurope.com.

Good articles, both - thanks for linking.

On the Cap test, I guess I read it slightly diff than the way you did, iMax. You're conclusion was that the Cap can't be pushed as hard as a Nacra or a Tiger off the wind (the article actually says Tiger), but the telling line for me is this;



I guess with talk about pitching by F18s in general, it might leave one with the impression, since it was a review of the Cap specifically. I have not noted the "Achilles heel" the article indicated the Cap suffers on the start line - when I get up on the line, it holds position well and I haven't found myself in trouble yet... certainly not in any way related to the dagger boards as the reviewer states he has heard from sailors racing against the Cap. Where was the editor on that bit of "I heard someone say..."?

On the Nacra review, I was pleased to note many of the similarities in design between the Cap and the Infusion - gybing boards, cordage and fit out, mast, extra volume in the taller hulls, etc. I think these are the elements we'll continue to see developed in the forseeable.

VMG - on the Nacra review, what happened to the "Answer Back" section? Is this a draft, or is it published already?

Thanks again - good reading. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

hi john, i found the same article (on the infusion) with the answers back from nacra europe.

My understanding was that Capricorns no longer have Gybing boards. I was told that they were not as successful as hoped and had to much drag. They probably also contributed to the slow off the start performance of the early boats. With this in mind I was surprised to see them on the new Nacra.

John, You've got a brand new Cap. Does it have gybing boards?

This is what we saw at the North American F18 this year.
Misha said on the last day he drove is bows in two to three times on the last run down wind on Fri. (but didn't flip)
bare in mind that of the 23 boats that did go out friday only 5 managed to avoid going over. And I'm almost certain that of the 5 that didnt all three types of boats were included.
Some of the new Nacra Infusions had some problems.
some of which being, daggers not fitting into dagger well,requiring some filing to the dagger. Also a dagger blew while in use. On Fri someone on an Infusion running down wind had mast fold. And two of the Infusion had some minor collision and took on water.

-------------------

You can PP anything if you try hard enough. I've sailed with Capricorns since the first day they were launched and seen plenty of nose dives. Are they any better/worse than any other boat??? I don't think so.

IMHO the major reason why the winner is a Hobie/Cap/Infusion these days is the sailors ability and maybe 10 - 15% the boats being suited to the particular conditions of the day.

Tiger Mike

I agree, it is too easy to confuse sailors' abilities with boats' abilities.

Would have been great if Micha and Carrie would have sailed an older Nacra at the NAs, because they would have still dominated the event. Technology is no replacement for talent.

I picked my new boat based on personal preferences and quality of workmanship. After getting a taste of sailing the Tornado I wanted a boat with great 'feel' to it.

CAUTION - 1 post troll with half the story.

Well put, Jake.

I was talking to Will Sunnocks about this a while back.

My memories of the conversation are thus



I would say that simply ther Capricorn behaves very slightly differently at a critical point down wind, and people just needed to learn to work out where this point is.

The last posting is right on the money, If you look at the hull shape in the right light you will see a vee from about 4" up from the bow to just past the front beam, The prototype was worse being the vee was 2" up the bow to the front beam, when you get the bow under the water to the vee it will hunt for the bottom, it is especially prone to happen in very gusty conditions, where you have little time to react, once you get the hulls up on a "plane"? it dosen't happen unless you hit a wrong wave. One day we were training in strong 25 gustting 30 knots on the pototype and it was almost impossible to get it going

What a load of rubbish

Just so this troll doesn't get off scott-free, I wasn't even there and managed to get the WHOLE STORY.

Nacra is putting out a boat a day on ONE MOLD. There are undoubtedly going to be quality control problems with gelcoat not be allowed to cure completely and so forth -- the factory is trying to keep up with demand.

Secondly, the mast that folded, was because it was honking, and the mainsheet came out of the cleat. I'd invite you to try the same on your tiger. Get back to me with the results hot shot.

I'd love to go down the list of quality problems I've seen with all kinds of Hobie products, but thats old hat, and I'm new game.

Tad replying ala SA style. OUCH! get'em.

Yep, from my experiences, Scooby's post is correct.

I have writen somewhere here before that the Capricorn and I believe all these new designs (Blade, Infusion) give a false sense of security for new sailors. They feel like they get up and plane on the down winds and give you the impression that you can push them a lot more.

When the hull tips forwards past the horizontal, it can dive pretty quikly. It is just a matter of getting to know the boats limits and finding the point to back off.

Myself and 2 other Tornado sailors from our club, all have moved across to the Capricorn and we all agree on one thing..... You can not push the Capricorn as hard off the breeze as you can the T. The extra 2 foot of bow on the T makes a big difference. All 3 of us tripped over on the top mark rounding often when we first got the boats. Leant pretty quickly to not throgh it around the top quiet as agressivly as the T.

As for the centerboards breaking on the Infusion..... Well the Capricorn also had this problem initialy whilst the manufacture was still working out the loads the long skinny boards were under. Since then, Goodall futher developed the Caps boards, adding more carbon in the high load areas and now seems to have fixed the problem. Expect the Infusion to go down the same road.

We do not use the toe strap, just the chicken line.

We have stuffed the bows on the Cap and T, however never cartwheeled whilst using the chicken line on either boat.

Spoke to Gashby about this on the weekend and his experiences..... He said they have found the same results, however they have cartwheeled dispite the chicken line on rare ocasions. Must of stuffed it big time..... Or may be my 95 kg crew hanging of the back helps keep it upright a bit more <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Hooray for the big dudes! <img src="http://www.catsailor.com/forums/images/graemlins/laugh.gif" alt="" />

We've only gone down the mine on the Tiger once since fitting a foot strap almost two years ago and given that we went down so hard that I was thrown clear of the boat from my location sitting on the tramp, I'd be surprised if a chicken line for my crew (92kg) would have made much difference.

*hugs and kisses for my N20 bows*

what is this "pitchpoling" and "going down the mine" that ya'll speak of? :P

Maugan
i know what you mean about the 20, but we did manage to go down the mine on ours quite often, once it came up with shoal of tiny fish on the tramp! I can mostly put it down to an early model baggy nylon spinnaker that really did us no favours,it eventually brought the mast down in a nice deep mine!
I have never felt 'safer' downwind than on the Infusion, even with only 60kg on the wire behind me. We did a worlds qualifier race this season [against tigers and caps] and the wind got up and up until no-one could put their kites up. At the end, we looked behind us after the down-wind finish and we were the only boat left standing! 3 guys went through their own mainsails in that one.

Paul GBR7


Yes i know the worlds are open and we dont need to qualify for slots, thats just how we rank our UK events.

I would like to raise the comments by MauganN20

Nacra is putting out a boat a day on ONE MOLD. There are undoubtedly going to be quality control problems with gelcoat not be allowed to cure completely and so forth -- the factory is trying to keep up with demand.

Please this is not a Nacra, Capricorn or Hobie bash just a comment. Are we as consumers willing to accept that manufacturers can knowingly make a product that is sub standard and then support them?

I believe for most of us, sailing is a “luxury”. After we pay the mortgage, the credit card bills and general living cost the rest of the money goes to out “luxury” items such as sailing boats. A new Nacra Infusion is reasonably expensive (as is all new F18 so I am not saying it is more expensive or attacking their pricing). Surely as a consumer I would expect a quality boat that has gone through some quality control. For me the excuse “we have only one mould and we are trying to produce as many boats as possible to keep up with demand” This is really saying as a company “we are trying to maximise our profits by reducing quality control and producing as many boats as possible while the market will buy it.”

As I said this is not a Nacra bash I am just wondering what we the sailors/consumers are willing to accept boats knowing there is a high chance of failure. Also in a few years a lower resale as the buyers say “well that is one for the first batch of boats and we know the quality control was not there so there is higher chance of failure”.

Maybe I am wrong and people are prepared to accept lesser quality control for the product they want.

As I said this is not bashing any manufacturer just what the sailors are willing to accept.

I don't see the problem, any factory will try and do a mold a day. Lay it up today and knock it out tomorrow morning is what they all do. That would give each hull about 20hours in the mold. How long do you want?

I changed my Nacra F18 for a Capricorn just before the UK Nationals. First impressions were that it was faster upwind
but pretty similar downwind, it is however much lighter to steer than the Nacra. The training day and first day of racing proper at the Nationals were fine but then the wind just kept picking up on each subsequent day and I found it very hard to sail downwind in conditions that, while challenging, I would have been happy with in the Nacra. Saying this, the fast teams on the Capricorns had no problems at all and so I would summize that the problems I had were down to a)technique + ability and b)setup. So while I pitchpoled my Cap more times that I want to remember I think this was more me than the boat, the others seemed fine - and it's worth noting that it wasn't just me going swimming, the eventual winner pitchpoled his Tiger.

TMG mentions the earlier qualifier in Pevensey when the wind reached 39knots - I don't think that James and Gillian capsized their Cap, but retired after their jib blew out.

GBR6,

Are you coming to Grafham for the Open / F18 Inlands ?

Scooby - that's the plan, along with at least one A.

Its more like "We're trying to get peoples' boats to them (that they've already paid for) before the next <insert major regatta here> and quality may suffer."

Let us not forget this boat is employing a new building method, and there are bound to be wrinkles to iron out in the process.

As for the N20, We've never pitched it going downwind with the spin up, even in some pretty knarly sea states *knocks on wood*. We have pitched it while beam reaching when my lard-butt was too far forward during a "between the condos, offshore gonzo 30 knot blast" (Quote from Jake Kohl).

Good ho !

Looks like I'll need to let the club know they need to buy more beer !

Is this on top of the more they needed to order because Mark_P and Sailwave are coming? <img src="http://www.catsailor.com/forums/images/graemlins/confused.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

I agree, it serves no one to make excuses for defective work. How many rudders and daggerboards have we seen expode this year? And that was not the first mast to go either. We should be demanding that these issues be addressed instead of making excuses. Whether you're sailing Hobie, Nacra, Capricorn or whatever I think it's important to make sure we provide the proper 'feedback' in the hopes seeing a better product next year.

And Maugan - I have lost the mainsheet several times on my Tiger without breaking the mast (I did bend one).

Umm, I thnink we'll need a bigger bar....

My post wasn't meant to be an "excuse." It was meant to inform people as to why these problems may be occurring.

I've seen some blown up boards, I know they had some issues during Alter Cup as well. Its really sad to be honest.

If you're scared of the quality, then don't buy their boats.



Anymore ancedotal evidence to throw on the fire there? <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

You know as well as I do it's all in the name as science; evidence to date strongly suggests that Mark's performance on day 2 is directly related to the quantity of alcohol he consumes on the evening of day 1.

<img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" />

Resin infuion is not at all a new building method, The techniques for doing it are well established by now. Jack would like you to believe the they are the first to build cats this way. They are not.
Nacra has never been a quality first outfit.
The flippin boats weigh 400 lbs. They should be bulletproof.

Eric

I heard that Nacra is not using the Infusion process to make the new F18 (infusion). Is this true!

You guys are something. No, it's not true. I've been to the factory and seen infusion in process. Some of these posts are getting a little slanderous...

http://www.teamseacats.com/2006/04/13/infused/

Jake,
Thanks for the post.

What? I guess you would rather pay Marstrom prices. The quality that PC puts out is very good. Much better than some of the other stuff out there. Another well known company is in a law suite right now about their "quality". As for the rudders breaking because not enough carbon, that is a design issue, not a build quality problem.

I heard HobieF18 is a toolshed.

(not a just a tool, or a tool bag, but the whole friggin shed)



OHHH how ignorant am I! I must walk around regattas and gaze my eyes upon resin-infused performance/nacra catamarans all the time, since yaknow, its so popular and Nacra has been doing it for a while....

I swear....

Maugan..... You spend far to much time on SA <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" /> <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

Nacra has been pretending they were the first to use resin infusion for their beach cats for a while now. They are most definately not.

An interesting detail is that more and more sources are claiming the the other builders have dropped building using this method, and it is now said that Nacra has stopped doing it with the A2 as well. Problems concerning proper wetting out of remote area's. Other builders are finding they can produced better quality boats with the old technology then with the resin infusion proces. So that took care of the claimed advantages of resin infusion. It seems to work for thicker, heavier and more low tech laminates found on cruisers and powerboats but not on lightweight thin laminate racing beach catamarans.

Wouter

And an even bigger padlock to lock the locl constabulary out. Unless they sail of course.
Wayne Marlow and the three Scots are joining us so may wish to consider hiring a Marquee!!!

I hear you say this time and time again - where exactly did Nacra claim to be the first catamaran builder using resin infusion? I never heard it. In fact, they didn't really care to call the boat "Infusion".

Sorry forgot the thread. IMO "pitchpoling capricorns" It's as easy as the simplest mistake, like nearly every other beach cat! not pitchpoling them is down to the pure skill and team work of the helm and crew, again like any other beach cat. This idea that just because the bows don't take on the same appearance as the (dated) Tiger shouldn't automatically send out shockwaves that the Caps bows are under volumed. I realy enjoy watching the development of Cat hulls from what I consider to be old designs such as the Unicorn, Shearwater and to some extent Tornado right through to the new Auz Flyers and Caps. These designers I hope are setting new benchmarks and In the future people will soon forget that the people who first sailed these designs had to get use to a different technique due to the advanced hull shape.

Any my point is, that while it may not be the first cat to be infused, its the first time PC/Nacra has done it.

Maugan N20,
Lets not go POSTAL on us or me.
Unless you are a Postal employee.

-------

Looks like you picked the wrong week to stop breathing toxic fumes.

So, what are the most common manufacture methods for high performance cats these days? Not being a builder, I've only heard about:

Foam core layup
Vacuum molding
Resin Infusion (I'll have to look that up)
Resin impregnated wood

I'm sure I just offended just about every builder, but a HELPFUL discussion on construction methods may help us commoners.

And before I get the flame-fest... I'm doing a search..

Those toxic fumes keep the voices in my head quiet.

lamination basics as I understand them. Note: I am not in the boat building buisness so this is just my take on the whole deal.

Most beach cat hulls are composed of a paint/gel coat layer then outer skin then a lower density core then an inner skin.

The outer layer is gel coat (thickened polyester or vinal ester resin with UV inhibitors and coloring added. Or it is a catalyzed linear polyurethane paint (Awlgrip for example)

The skins must be able to withstand tension, compression, offer impact resistance, and adhere to the outer paint/gel coat. They are typically made of a woven fiber (fiberglass/ Kevlar/carbon) held in a matrix of resin either epoxy, polyester or vinyl ester resin.

The core is a low density material that must resist shear loads, not dent too easily (high crush strength), bond to the skins, and not weigh too much. Not absorb water Common core materials are foams in various densities and types, end gain balsa, expanded cell nomex (honeycomb).

Layup methods in order of decreasing expense/quality

1. Prepreg/autoclave cure
2. Prepreg hot vacuum bag cure
3. Resin infusion
4. Wet layup vacuum bagged
5. Wet layup not vacuum bagged

1. The cloth comes preimpregnated (usually with epoxy) with the exact fiber to resin ratio for optimum strength. Material is shipped and stored cold and then gets flexible at room temp. After the part is layed up in the mold, it is placed in a vacuum bag and placed in an autoclave generally cures at 100+ °C at 5-6 atmospheres of pressure. Yields very good compression strength which is why this is used for making carbon masts and beams.

2. Same as above, just heated with only 1 atmosphere of pressure on the bag. Slight loss of compression strength.

3. All the glass, core, etc is layed up dry without resin. It is placed in a vacuum bag with multiple inlets for resin and be pulled by vacuum through the fiberglass towards the vacuum source. The advantage is low waste, the ability to work slowly on getting the fibers into place ahead of time. It requires a resin that does not cure before it is fully wet out lower viscosity, and if you are not careful there can be dry spots that never get wet out. This may not be visible if you sprayed gel coat into the mold first.

4. Wet out the glass by hand with a brush and squeegee, place in a vacuum bag and cure at room temp. The breather absorbs most of the excess resin

5. Wet out the glass by hand with a brush and squeegee



Cloths in order of expense and quality costs are per ~6 oz 50” wide cloth

Carbon fiber cloth Highest stiffness (Tensile strength) (comes in different grades of stiffness) 40-60 $ yard
Kevlar Best impact resistance good Tensile strength 30-40 $ yard
S glass fiberglass very good impact resistance Moderate Tensile strength 30% stronger 15 % stiffer then E glass. 17$ yard
E glass fiberglass Lowest Tensile strength very inexpensive 5.50$ yard

Resin in order of performance

Epoxy 40-75$ gallon
Epoxy resin is known in the marine industry for its incredible toughness and bonding strength. Quality epoxy resins stick to other materials with 2,000-p.s.i. vs. only 500-p.s.i. for vinyl ester resins and even less for polyesters. In areas that must be able to flex and strain WITH the fibers without micro-fracturing, epoxy resins offer much greater capability. Cured epoxy tends to be very resistant to moisture absorption. Epoxy resin will bond dissimilar or already-cured materials which makes repair work that is very reliable and strong. Epoxy actually bonds to all sorts of fibers very well and also offers excellent results in repair-ability when it is used to bond two different materials together. Initally, epoxy resin is much more difficult to work with and requires additional skill by the technicians who handle it.
Vinylester resin
Vinylester resins are stronger than polyester resins and cheaper than epoxy resins. Vinylester resins utilize a polyester resin type of cross-linking molecules in the bonding process. Vinylester is a hybrid form of polyester resin which has been toughened with epoxy molecules within the main moleculer structure. Vinyester resins offer better resistance to moisture absorption than polyester resins but it's downside is in the use of liquid styrene to thin it out (not good to breath that stuff) and its sensitivity to atmospheric moisture and temperature. Sometimes it won't cure if the atmospheric conditions are not right. It also has difficulty in bonding dissimilar and already-cured materials. It is also known that vinylester resins bond very well to fiberglass, but offer a poor bond to kevlar and carbon fibers due to the nature of those two more exotic fibers. Due to the touchy nature of vinylester resin, careful surface preparation is necessary if reasonable adhesion is desired for any repair work.
Poly ester is the cheapest resin available in the marine industry and offers the poorest adhesion, has the highest water absorption, highest shrinkage, and high VOC's. Polyester resin is only compatible with fiberglass fibers and is best suited to building things that are not weight sensitive.

Outer coverings. There are 2 choices gel coat, and paint.
Good paint is tougher and lighter but not as thick. Awlgrip is an excellent product for usage but it is nasty stuff. Harder to match repairs.
Gel coat is cheaper and thicker so it can be scraped a bit without exposing the skin. Easier to repair small patches, hard to refinish a whole boat.

Back to work

You lost me at wet layup.

Ouch....

OK...manufacturing methods for producing a catamaran (or anything) from a female mold can fall into two basic categories. Hand Laid or Vacuum Bagged. "Foam Core" is about having foam between layers of fiberglass and you can build a boat with foam core construction using either method.

Hand laid hulls are exactly that. Gelcoat is sprayed in the mold and allowed to tack up. Precut pieces of fiberglass are laid on top of the gel coat and wetted out with resin. Then a foam core is placed on top of the wet fiberglass. Then more fiberglass on top of the foam core is laid in place and impregnated with resin.

For a simple vacuum bag operation, the same previous processes would take place. After all this glass is 'wet' a perforated layer of plastic goes on top of it all, then a layer of absorbant stuffing sheet (usually poly-stuffing), and finally the vacuum bag. A small port is installed in the bag and vacuum applied. As the air is evacuated from inside the bag, the ambient air pressure starts pressing equally around the mold and squeezes excess resin from the laminate through the perforated plastic layer into the stuffing. You end up with a laminate with less resin, less weight, and more fiber density resulting in a potentially stronger part.

Resin infusion simply takes vacuum bagging to a new level. You still spray the gelcoat in the mold but you lay in the fiberglass, core, and reinforcements in the mold dry. You don't put in the perforated plastic layer or the stuffing - only the vacuum bag. You pull a vacuum on the dry layup and once the bag is well sealed (and you've chased all the leaks), you connect an open pail of resin to the center of the bag in several places (where ports have been pre-arranged) and let it start to suck the resin in. The resin will slowly work it's way through the laminate. Once one area of the mold is fully impregnated with resin, you clamp off that port while the rest of the mold infuses. Resin infusion uses less materials (no more perforated layer or stuffing), you have more time to lay the materials in and get them right, and you get a very controlable amount of resin in the layup. The drawbacks are that the port and flow arrangement is very critical to get resin in all the nooks and crannies, the curing time of the resin (affected largely by ambient and mold temperature) is very critical (you don't need it to start gelling before everything is infused!), and the (low) viscosity of the resin is super-critical.

sorry to all of you! my only intention was to get info how the capricorn behaves with the kite up. i dind't want to smoke you with (poly)fumes. in the time this discussion has taken i've made my mind up. i'll try to sell my nacra f18 (which is a real good deal!!!) and trade it in for a capricorn. i'm comfident that i have enough skills to take my wife for a spin at windforce 6. i hope i'll be able to let you know how i like the capricorn after the long winter. (that newzealand tornado movie, in the other post, might help me through the winter.

farts in a thunder storm

Nice write-ups Eric and Jake!

Actually, vacuum bagging is not related to the process of the glass being hand laid or not. You can hand lay (simple to understand) the glass, or you can shoot it in with a chopper gun. I would call resin infusion "hand laid" as it requires careful positioning of the glass layers by hand.

Vacuum bagging is a process that holds the glass in place as the resin cures. You can use a hand squeegee to work the glass and resin till it sets up or you can put the mold in a bag and turn on a vacuum. The squeegee can be good at removing more excess resin, but the vacuum bagging is less labor. The vacuum bagging is required on our foam core layup as it forces the foam to adhere to a concave surface.

Our glass process is:

- Gel coat sprayed into the mold.
- 1 st layup is hand layed glass and resin worked with a squeegee. Cured.
- Foam core is laminated in place and vacuum bagged till cured.
- 2 nd layup (hulls inner layer) is hand laid and worked with squeegee.

We do not use the vacuum bagging on the second layup because it can shift the glass and cause wrinkles. Not good for the structure.

However you decide to classify them, vacuum bagged fiberglass laminates have a much higher fiber to resin ratio than a hand wetted ambient pressure cured layup. Vacuuming the layup does more than just hold the glass in place in that it also compresses the fibers together and reduces the resin volume (much more than you can accomplish with a squeegie). You can control the amount of compression and fiber/resin ratio by simply adjusting the amount of vacuum applied. For you doubters out there, next time you are near a vacuum bagged hull, tap on it with a knuckle and then tap on the hull of an ambient pressure cured boat. The vacuum bagged boat will sound like a steel drum - the other will make a dull thud.

I don't know. Maybe with much higher vacuum. We quit doing it on the 2 nd layup for weight and consistency issues. The boats are lighter now and look much nicer on the inside because we hand work the glass and squeegee out the excess resins.

Jake,

The cure time of the resin can be configured for infusion, especially so with epoxies. There are epoxy curatives that will give you 5 days or more work time at room temp. There is one that gives you 6 months(!) But with only modest heating (120-180*F) full cure in a few hours.

With polyester, the Sunrez system is always an option. The Sunrez system will never cure until exposed to a strong ultraviolet light source.

Then there are the 'static' mix tubes.

http://www.chreed.com/tah_mixers.htm

The resin and catalyst are stored seperately and only metered, combined and thoroughly mixed at the moment of infusion into the layup using static mix tubes, greatly reducing the chance of a mishap with gel time vs infusion time.

I saw and participated in a buildup at After IBEX a couple of years ago that used mixers like these. We built a ~12' dinghy in about 45 minutes from empty mold to finished boat (with plenty of guidance from our instructor <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" /> )

So keep in mind that there are basically two types of composite boat manufacturer in 2006: Those using some form of resin infusion and those who are going to use some sort of resin infusion soon. If Nacra or anyone else making boats has begun using infusion, then they still are. No way they would go back. Better to work out the bugs (if there are any). This is how boats will be built from now on.

Jimbo

IIRC the way US laws are going at present with respect to emissions and staff exposure to chemicals and fumes, in a few years you won't have any choice but to infuse if you want to build composite boats in the US.

I understand that a large part of the reasoning behind the proposed law (I think they put a guidline year date in the law) is environment and worker health....this is likely a stupid question, but where do the fumes go if you are resin infusing?

Jake,
'Fumes' are the result of the volatile reactive solvent styrene (aka vinyl benzene) coming into contact with air and evaporating. If you have a closed can of styrene, you don't have any air contact, no 'outgassing', hence no fumes (duh <img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" /> ). Resin infusion is a 'closed' process. It's like building a boat without taking the caps off of the cans of resin.

Jimbo

...and the vacuum exhaust? Back into the can? I would think that is still going to be an issue. How do you dispense of the fumes in the vacuum exhaust?

In the case of infusion, you only have vacuum exhaust and outgassing while pulling the resin into the layers of fibers. This is done in a short time, from then on you only maintain the vacuum, and the amount of outgassing is very, very, small as long as you have a good airseal. A very tight vacumbag is a necessity when using infusion, otherwise you get faults in the laminate. It is therefore standard procedure to check the vacumbags integrity before you pull the resin in.

On the topic of laminating by hand.. A skilled worker can achieve about the same resin/fiber ratios as a wet layup with vacuum, but he uses more time and is exposed to the fumes and chemicals for a longer time. I am not certain infusion results in stronger/lighter parts when compared to wet layup with vacuum. I think infusion uses more resin to fill all voids in the foam surface, but have not had the opportunity to compare weights.

I have done a lot of both - but I confess to not previously using rollers to laydown a hand layup...Having vacuum bagged 8 layers of 11oz fiberglass into a laminate less than 3/16" thick, I would find it astonishing that this can be accomplished without a vacuum. Secondly, if you do some research into building a foam core laminate, doing so under vacuum and filling the rough surface of the foam creates an extremely superior bond and increases the strength of the structure 10 times or more. If I get some time, I'll try to locate that article.

I have done side by side hand laminations and vacuum bagging and achieved substantially different results (but admitedly was not using the beaded rollers at the time for hand laminations).

Even if you vacuum bag without infusing, you still get a much better bond to foam cores. The infusion process allows you to place all your reinforcments before having to deal with cure times and reduces some of the materials needed for production.

Jake,
I've never been one to use those little rollers either. I got into composites from the aerospace side and learned the 'Rutan Method' which uses plastic bondo squeegees or the rubber screen process squeegees to both spread resin and remove excess. Very fast and effective. No brushing at all. You might be able to find one of Rutan's videos where he lays up a whole foam core wing in about, oh, 15 minutes or so. Amazing!

Jimbo

jimbo

Jake,

I always put on a layer of epoxy thickened with collodial silica on the foam first, to fill all gaps. Then I put on the glass and wet it out. I hope I save some weight that way and still have a good bond..

I have used a rigded alu roller, but found it to be too messy. For thick laminates it can be nice, but most parts on cats are so delicate that I prefer a squeege. Squeege and vacuum is my preferred method.

Rolf wrote :




I think I wrote earlier that several other builders found that the old method resulted in better quality boats and have disgarted infusion as a result. Infusion did not result in lighter hulls. It had increased the risk of warranty issues because of insufficient wetting out of the laminate in remote area's. These builders tend to make a very large portions of quality lightweight hulls. Maybe they didn't try hard enough to make it work, that is possible. But rumour has it in the A-cat cirquit that also Nacra has reverted back to the old technology for their A2 catamaran. For very much the same reasons. However the last claim is a single source claim so I categorize it as less dependent.

It seems that infusion is mainly advantageous in the way of cleaning up your production line and satisfying more strickt environmental regulations. In the way of quality of the laminate it doesn't seem to be better then the old vacuum bag techniques. It certainly doesn't appear to be better at all autoclave techniques with manual layup.

Wouter

A good strategy for where to have the resin inlets and vacum ports is necessary for proper wetting out of all fibers. There are flow-simulation software available to do this for you, which might be smart to invest in if you are going to do production parts. A fellow countryman of you has written extensively about his experiences with infusion while building a F-39 trimaran: http://www.fram.nl/

Fiber fractions in the 55% range are consistently echievable with RI methods. That's certainly good enough. Autoclave is not really applicable to the construction of most beach cats since they use foam cores. Autoclaves are only used when you want compaction pressure greater than one atmosphere. The lower density cores do not do well with ths type of pressure, especially at elvated temperatures. Autoclave copaction/curing is the territory of the Nomex honeycomb cored boats, which is to say, the high-end boats. I have managed to crush some of the lower density PVC foams with only a good vacuum at room temperature.

One small problem with RI is that it may tend to oversaturate certain areas of the dry stack-up, like the edges of scrim & score foam, or corners where foam pieces meet together. In hand layup, these would be hollow voids, which is OK since it is in the core anyway. But with RI it winds up being solid resin. Stronger? probably, though not in any meaningful way. But certainly heavier by as much as a few pounds per hull. There is usually a simple solution in changing certain details of the core to avoid these resin pockets.

Jimbo

Okay, my 2 cents having looked at both boats, with a serious purchase pending. You can dump any of these boats at a gybe, but (all other things equal mass, mast position relative to center of effort, sail area) I find that how aggressively you can bear off, coupled with, foredeck hull volume, and hydrodynamic drag, and mast postion relative to center of effort can be pretty boat-specific. First, both the Cap and the Nacra are really nice boats. All this about masts snapping is baloney. Unless you raise a phone-pole on your F18, any mast will snap with a spin if not appropriately rigged for the conditions. Learn how to set your rig tension and read and repeat: big breeze, no mainsheet tension or incorrect diamond-wire setting, with any spinny= *SNAP*. If you think, with thousands of pounds of wind force pushing on it, that mast strength is solely a function of the flimsy aluminum and not the assisting stay settings and mainsheet tension, I can recommend a physics class. (Don’t be so dumb.) Having souped up the 5.5sl (and sailed most other F18’s), I can say that there is, a critical moment at the gybe when the kite goes up that is extremely boat-specific. When the kite goes up, the top of your boat wants to scoot forward, but its, draggy hulls (they are in water, a much more dense a fluid than air) are slower to accelerate and hold it back. This acceleration causes the center of effort to move very far forward until such a time as the hulls can catch up a bit and get back under the rig. Once sufficient speed is achieved on a catamaran with a spin, the leeward hull begins planing, the hull slips forward under the mast, and the center of effort moves aft again, and the process is facilitated by the lift provided by the spinnaker on the front of the boat, re-directing air both downward and aft. However, on each, hull design governs acceleration and is quite different. Based on my experience, hull design and water chop largely govern a propensity spectacular catamaran gymnastics at the gybe. At the downwind gybe, nose diving is a function of lesser volume fore, and less leeward, outward side hull curvature, and how much water is on top of the hull as the top of the boat (mast, sails) tries to go fast and the bottom (hulls) drag behind. Narrow sleek hulls and far forward CE design elements provide greater ease in the hull hunting for the bottom of the ocean in a big breeze as the CE tips fore on the boat at the gybe, with hulls pointing to the bottom of the ocean for a bit of time until planing begins. At the same time, the sleek hull features providing less overall resistance in the water (hulls more slippery) and better acceleration. Having souped up a (spinned) a nacra 5.5sl and sailed it as F18 (Second ! on day one in a big breeze, and...umm, oh yeah, dead last on day 2 in a light breeze)... the low volume hull 5.5sl (spi) with the F18 class in force 4 winds was very, very fast downwind in heavy air, especially after it got rolling, presumably because of the small hulls. Once planing, the old boat actually felt very stable. However, watching the 5.5’s low volume hulls torpedo until the boat started to plane at the gybe is a pretty “exhilarating” experience. This acceleration is not necessarily bad (I have lots of experience with the my skinny, low volume 5.5 hulls!), but does influence how hard you can (should) push the boat immediately off a gybe-I go a little deeper and more s l o w w l y). Reduced hull volume can make for a startlingly fast acceleration but managing the boat during this point, requires a bit of care, until the hulls begin planing (if it is breezy enough). Just looking at the cross-sections-one would then expect the Cap to provide better acceleration, is probably quicker to plane, but maybe a bit more likelihood of a stuffed hull during a reckless, hard gybe’. The big volume on the Nacra hulls may provide a bit more overall stability at this point, at some expense of overall acceleration. It’s a trade off. Once planing, though, the boats are about the same. As for quality, I think AHCP (Cap) makes a really nice, solid boat, but then again, it costs more than the Nacra Infusion. Bottom line? Learn your boat, avoid generalizations-all F-18’s are pretty fast.

Lost me at "multiple inlets".

When did W change his handle?

Lost me at equal mass

Looking at that makes my brain hurt.

I read it twice. The take-away was that he once had a fast 5.5. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Just keep the frickin' thing moving fast

I may need to consult my abacus the next time I gybe to determine the quantum momentum mass fusion dispersement of my hull penetration.

Okay let me try again...Yeahhh, Windy means boat go fast and maybe almost tip over...grunt...fart. yeahhh. (How was that?):D

Much better, but you lost me at windy. De de deee!

You can tell the ones that hang out at the beer wagon to long. Me included. I've been told Beer kills brain cells. But can't remember who told me.

Have you seen the pictures from Catfest? I couldn't find one where you didn't have a beer in your hand. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

let's see

you want a fast boat

with maximum sail area and probably a spinnaker

that you are going to sail in as strong a wind as you dare

and it would be good if it didn't pitchpole

hey we ALL want that

http://video.google.com/videoplay?docid=-5375388720238697079

at 2:08, it'a a capricorn. The video was shot at the Trois-Rivière event in Quebec, except the Capricorn which was at the lake of two mountains event 2 summers ago

You mean "Beer Fest"
There was no wind.... what else was I suppose to do..

What I meant was... what's the deal with the empty hand? <img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" />