CATAMARAN BUILD QUALITY: The TRUTH Brokers DON’T Want To Discuss!

Let's start with a truth: Catamaran build quality varies wildly.

In this episode we are going to go talk about how you can get this information and enable you to make a better decision.

To accompany this episode, we have made a FREE catamaran buyers guide for you. This should form a starting point for you to do your research, armed with the information that brokers don't seem to always want to provide. Simply sign up to our newsletter and we will send it straight to your inbox!

Now, unless you are a millionaire, your boat purchase is going to cost a whole lot of money and possibly be the biggest purchase aside from your house. So it is so, so important to know exactly what you are buying.

In this episode we are going to discuss how the differences in build quality affect performance, weight, and comfort. We are also going to discuss how build quality and materials are used to save money rather than deliver the best material for your money.

And, I do ask that you use this episode as a basis for your research. The internet is a valuable tool for research. Use sailing forums, owners websites and scientific articles and videos for further information on the material science of construction material. We are after all offering opinion and not a professional view. So why would you take our word? Don’t! However, do your own research and the next time you are viewing or considering a boat, ask the broker these questions and see if you can get satisfactory answers.

[rabukan]

Nick, you continually impress with your astute probing. This tech series is not only informative, it is important to all catamaran owners or potential owners. I have watched each episode with Antoine a few times over and picked up something new each time. Excellent presentation, and sorry he has to go back to work. I have about a dozen more questions I can think of for him. Thanks for the education.

[edaalvik]

As a engineer with experience in these material systems, I thank you for technical explanations. I think one particular Catamaran design to understand is the deck to hull material process. Maybe in a future video you could discuss the various ways the deck is attached to the hulls.

[dougmarder]

A very good intro to a complicated topic! I know this could have gone on for hours, but I would have added some more discussion about both the varieties of sandwich materials other than foam (and not all foams are created equal) and their pros and cons above and below the waterline, as well as how much the lay-up of the GRP/E-glass/S-glass/CF in combination with the sandwich materiel affects the strength, compression, etc. (this was lightly glossed over). Builders are evolving from hand-layup to wet-vacuum to infusion as they get better financing, tooling and experience with the process, but even with the best materials and processes, lack of attention to the properties needed in specific components leads to disaster. I have been riding in pelotons where super expensive carbon bikes exploded under their riders because either the bottom bracket or the top tube were not sufficiently reinforced. I have seen foam cored skis go 90 degrees. And the latest edition of the Vendee Globe shows just how difficult construction can be even with relatively unlimited budgets and the best engineers. I am sure no expense was saved on the construction of PBR and Hugo Boss, yet obviously they were pushed beyond the limits of their materials and construction techniques. One other aspect of this discussion is the economics. Obviously, we all want the best materials and construction, but these come at a cost. What combinations are "good enough" for an ocean crossing cruiser?

[PopsGG]

Thank you for this video. I am looking at lower costs catamarans and after looking build specs they all use polyester throughout and plywood in the bulkheads. My biggest concern is osmosis.

[HeidiandFranny]

That was great Nick! (great editing as well). Really interesting break down on composite polymer construction. Sounds like there are compromises all over, but having a good knowledge of the basic processes is critical during the buying process. I think it speaks well of Seawind to freely go over all that they do. Very excited for you! Thanks again :) Franny

[colinboniface]

While this series has been technical, you have managed to explain it all in a really straightforward, easy to understand way. Sharing knowledge is the cruisers mantra. That makes a huge difference to people with little experience, to gain knowledge and up skill. Well done.The concept is brilliant. i can't wait to see the build underway...

[markomarkomarko]

Very useful info on materials from an experienced boatbuilder.

May I just add as a structural engineer than just using high grade expensive materials Vs lower performing materials does not necessarily give you a stronger boat.

Materials with better physical properties give you higher strength and stiffness per unit weight. They enable a competent designer to produce a high performance boat.

However, if you look at Vendée globe now you have a bleeding edge high tech boat made using top quality materials like Hugo boss breaking up and losing bits of the boat until, ultimately, retiring after 4 weeks of racing. And on the other end of the scale you still have numerous well-constructed fiberglass boats from the 1960s and 1970s still happily floating about. They are not nearly as fast but seemingly much stronger.

[SpiralDiving]

S glass is as strong as carbon (or even stronger in some tests) but its heavier. Talking about balsa, its not just the money end grain balsa has the best bonding strength and is most resistant to debonding/delamination and has better crush resistance than foam. It's also light. The trouble is rot when it gets wet.

[hansk.]

Nice vid Nick, although I think it's a bit quick to exempt balsa core as only chosen because of price. Working with balsa core requires the manufacturer to use a higher standard, ie: sealing the balsa where the core is perforated like thru hulls, deck fittings etc., typically, a high quality builder will remove the core in these areas. As for the wetting out due to water ingress, with the more commonly used "Infusion" methods these days, all gaps are closed off in the sandwich so that the transport of water through a damaged panel is restricted due to the fact that "End Grain Balsa" is used. In general, the resin to core bond is strongest in a balsa core panel and is generally stronger in compression and has superior sheer/ fatigue qualities. Basically, the bad rep comes from bad building practises, causing expensive repairs, like on screwed teak decks that start leaking for example. As a point of interest, in the DIY build kits from Schoinning Catamarans, the prefab Balsa cored panels are actually the strongest/lightest and most expensive option. Really looking forward to your build series and enjoy the build process. Cheers

[bedengler]

Awesome video with a great overview! Essential for everyone who‘s planning to buy a boat (not limited to catamarans)… 🤩👍

[cwhindman]

Re the discussion on hull to deck bonding, etc: I think the discussion got confused. There are really only 2 methods not three, gluing and bonding are the same thing using the same materials (epoxy or poly or vinyl ester), vs taping which applies an additional layer(s) of fiber across the joint in addition to the epoxy or whatnot.

[ReefRunner]

Super informative intro to the basic ingredients. You really have a knack for working the info out and putting it into a practical and useful perspective.

[earthstick]

That didn't tell us anything about the difference between epoxy and vinyl ester. Some people have suggested there are health effects. I suppose this is due to residual evaporation from the resin.

Jeff Schionning talks about the benefits of balsa being far greater compressive and shear strength, he suggests he can use almost half the thickness due to greater shear strength and less fibre either side of the core due to the increased compression strength. So despite being about twice the density of suitable foam the weight increase is not much but the result is stiffer. This didn't mention a property of foam is that it can follow a curved form easier unlike planks.

Then prepreg carbon fibre. Given that it has to be stored and laid up in a refrigerated environment then vacuum bagged, I cannot see how it is practical to use it for even a small boat hull. Laying up a hull takes days/weeks so how would a whole shed be kept refrigerated and how would people work in it? Smaller parts and specific areas perhaps.

Didn't explain gluing, bonding and taping the deck to the hull. Gluing and bonding sound the same. Taping, wet layup of fibre across the join? Presumably even if the two halves are bonded there is still taping to cover the join if only for aesthetics.

[seanwilson]

I'm curious why the fiberglass weave wasn't discussed, not all fiberglass is equal, and there have been major improvements in this area.

[feversol]

FYI. Even some of us who have never been on a boat like these, won’t be buying a boat or won’t even see a boat such as these find your video very interesting. I watch several channels of travelers such as yourselves and now will pay more attention to their vessels. You and Impi bring your life’s choice to a reality level others don’t achieve. Thank you.

[WillNGo]

Great series. Thank you. And the next question: What are all the bad things that can happens to cats? (There are really two major categories here: accidents that can happen to any boat, and then issues specific to cats.) What kind of accidents, hull breaches, damage, etc? When I was building my first sea kayak I read the book 'Deep Trouble'; accident reports - all the many ways I could die in my kayak. Probably why I'm still alive after 15 years of soloing.
I wonder if it's possible, without stepping on toes, or risking being sued, to do a video on specific types of build failures, keel loses, entire frames separating from hulls, layers improperly bonded, most of these are generally monohull construction issues. There's one major brand I won't go near, including their line of cats. I don't know if I'm justified in this prejudice - but I have it. What can and has gone wrong in boat construction that maybe doesn't show up until later? So there are two categories here: what still can happen even though everything was done right? and What are the things done wrong that have made it out of the boat yard?

[trentspencer]

Something I know for a fact is a big ticket item for many buyers is after market structural and system customisation options for a catamaran. Some manufacturers offer this and some don't. Another good video anyway, tech discussions are interesting.

[jimwapelhorst]

Hi,

Just went to your discussion on electric power with the UMA crew. My takeaway is a Hybrid powerplant!

[perrydiddle]

Excellent video. The obvious statement comes to mind “You get what you pay for.” Or, at least you better - if you are paying the price. Now, cats were singled out here. I would assume the technologies apply to monohull too. Or is there a difference? Also, do most boat builders offer choices within the same models? Or is one model made consistently with the same construction? Unless you get a custom boat, you have to weigh everything from weight, size, room, features above and below deck, handling of the boat, construction materials and construction methods. If you have a very limited budget, it must be so hard choosing and prioritizing features. How do you do it? It could be the difference between going for a new boat or used one, or even a very used one.

[anic]

Wow! amazing video. why has no one else done such a video and it's been left to Nick and Terysa. can you do one on build contracts and should you use solicitors etc? absolutely a fantastic video. Good on ya.