Most Reliable Hull Construction ?

[lorenzoSF]

Hi All,

This is my first post, so forgive me if the answer is already out there and I couldn't see it.

I am 38 and dream of buying a ~45ft cat in the next 3-4 years to start a liveaboard with my family, ideally for the rest of our lives. We plan to have some stable income while cruising, but probably just enough for the upkeep of the boat and family, so not enough to build a kitty large enough to buy another boat in 10 years.

This means that I would like the hull to last in the water for the next 40 years, ideally, without major problems. I think at 80yo I will probably have to live the last part of life on land, but full of great memories.
Of course there will be standard maintenance, antifouling, repaint, new gel coat, etc, but I hear about osmosis (for sandwich construction), corrosion (for aluminum or steel) etc.

I would like to know what is the best construction material for the long long term and ideally what specific cat you would suggest (keeping in mind 1. durability/safety, 2. living space, 3. performance).

Thanks
Lorenzo

[Target9000]

Both fiberglass (cored or not) and metal (aluminum or steel) will last a lifetime if properly maintained. The maintenance will differ but both are equally capable of lasting for a very long time with a modest cost of upkeep if you are vigilant about taking care of your investment. With metal you'll worry about zincs, corrosion, insulation, etc. With fiberglass you'll worry about making sure nothing is leaking into the core and blisters. All of those things are manageable.

I'd buy the boat you want so long as she is from a reputable builder and not over think the hull material. They're both safe, strong, and proven.

No expert, just my opinion.

Also, welcome to the forum!

[Cheechako]

Solid glass wont let you down. Cored glass might let you down. Steel too heavy for a cat. Aluminum can be great, but expensive and there is a risk of getting a "problem boat" electrolysis wise. Overall I would say solid glass is the safest route, although may be hard to find in a larger cat.
Also, for the long haul, go with thru hull propellor shafts rather than saildrives.

[delmarrey]

On the other hand I have a 30 YO foam cored hull that is still going strong. With foam core the hull is more flexible and can take a good banging without cracking (oil cans).

Whereas, solid glass is more rigid and it's corners are compromised. So well rounded corners on solid glass is desirable.

With that I will also say that, like Target stated, maintenance is your key to longevity.

As for Cats, one has to be more careful in construction. They do more then their fair share of flexing. One has to be aware of the joints between hulls, cabin and cross beams. For long term vs speed I prefer the heavier cats. But in a 45' your getting up there anyway as long as it's not a racer.


And I, also, would avoid saildrives. Being able to beach a Cat is favorable.

Here is a good site to start with. >>> Cruisincats.com: The webs premier cruising catamaran site. Dedicated to cruisin' catamarans and those who sail them. 50+ cruising topics & 1000's of links, largest used cat listings etc.

Personally, I like the Leopard, Privilege, & Dean.

[GordMay]

Greetings and welcome aboard the CF, Lorenzo.

[CarlF]

I agree that most hull materials will last with correct and sufficient maintenance. But if you are going to own a boat that long almost everything other than the hull and deck will be replaced or repaired.

Look for-

Replaceable fuel tanks, water tanks, and engines. All are likely to be replaced in less than 20 years. Figure out exactly how they will come out and the new ones go in.

Accessible and replaceable wiring, plumbing and hardware

Interior joinerwork that can be mostly unscrewed and removed for refinishing. Beware of lots of glue and epoxy in the woodwork.

Joinerwork that can be sanded and refinished (some boats today have weird finishes that can not be even touched up without showing)

A minimum of custom castings, novel materials, or unusual equipment that may not be manufactured in 20 years or earlier if the builder goes out of business.

Carl

[Sand crab]

45' is on the cusp as far as a lightweight aluminum cat. It seem the panels can only be so thin so larger than 45' and it gets lighter and more even weight wise with FG boats. But smaller than 45' and the aluminum is just too thick which means heavy and slow. And don't ever say you want a slow boat. There's a cat or tri for sale for what seems like forever now made out of steel and that's why it's still for sale. I would guess that less than 1% of cats made are aluminum so the selection is extremely small. There are no production aluminum cat builders and there are a very few semi-production builders.
The only modern cat builder that uses solid FG is Outremer but I'm not sure of their latest models. Core problems can mostly be traced to poor maintenace although some are due to poor construction, the Bumfuzzles boat being one. For the most part a poorly constructed boat would show it's flaws in the first 5 years or so. There are so many 40 year old FG boats still afloat that Fg has easily proven it's longevity. These are mostly monos because not too many cats were in production in '71. The almost 40 year old cats include Catalacs, Prouts, and Heavenly Twins of which I think were all solid FG. Although there aren't many epoxy production cats (actually, I can't think of any) they have less core issues because epoxy sticks to the core and everything else really well while polyester is notoriously "non-sticky". Furthermore polester is not waterproof while epoxy is. Nonetheless most boats are polyester and they still float so the poly must be sticky enough and epoxy bottom paints are used below the waterline. I would not discount the one offs and home-builts for the simple fact that most are built with epoxy and that is a good start. For instance there is a 1965 41' Piver Cat for sale that looks totally pristine. I'm sure it's built with either wood ply or planks and still rightside up 46 years later. Wood ain't neccesarily a bad thing. I would go for the best boat conditionwise and damn the construction materials. All of them can be good or bad. Good luck. BOB

[colemj]

That's easy. Glass over cedar core, then put it on stands in Tuscon Arizona. Or maybe in New Mexico. China Lake California would be perfect. Should last through your grandkids retirements. Keep the snakes and scorpions out and you won't have much more upkeep costs.

Mark

[David M]

How a boat is designed, including it's scantlings, determines reliability. It is not hull material alone that determines this. The third and fourth variables are maintenance and usage. You have to look at all four factors.

[lorenzoSF]

Thanks a lot to all for your insightful answers.
So it seems the general consensus is that a cored fiberglass multihull can last 40 years without issues as long as it is well maintained. Solid fiberglass might be better but there are not many options around (I think I have read that the Antares is solid glass below the waterline and cored above, but it seems a bit on the expensive side).

Any view of the different large brands in this respect? For example if I think of Lagoon, FP, Leopard, Nautitech, etc. you think any of them will do if well maintained?

Lorenzo

[David_Old_Jersey]

In an older boat (no matter how many hulls or construction material / method) the main issue to deal with will always be the PO(s).

Everyone has different pocket sizes, attitudes to maintanence (before or after stuff breaks), skills and knowledge..........and also differing sense of what looks good / ok / passable. In my case I like a boat to be functional, and interior wise immaculate (if I tidied up ) - exterior am not too bothered with cosmetically....but it's a 40 yo (plastic) boat.

Some people can keep a boat immaculate on a low budget for a decade or more - others can ruin a boat within a year (especially mechanically)........Plus some (most?! ) are quite willing to gloss over any "clever" DIY bodges that are not visible to the naked eye - and some actually don't know that there effort is a bodge........

But that's boats for ya

[Dockhead]

Originally Posted by lorenzoSF

Thanks a lot to all for your insightful answers.
So it seems the general consensus is that a cored fiberglass multihull can last 40 years without issues as long as it is well maintained. Solid fiberglass might be better but there are not many options around (I think I have read that the Antares is solid glass below the waterline and cored above, but it seems a bit on the expensive side).Lorenzo

I don't think whether or not a cored hull will last or not depends on maintenance. I think it depends on the initial build quality and the state of the art at the time the boat was built. There has been a lot of technological advance since the first cored glass hulls were built in the 60's or 70's.

Cored fibeglass has much better strength-to-weight characteristics than solid. Most high end monohulls over a certain size are cored, although monos are less sensitive to weight than cats. I wouldn't want solid glass in a catamaran, personally -- much too big of a performance loss for a theoretical reduction of risk of problems.

There are horror stories about cored hulls in cheap power boats like Sea Rays and very early cored hull sailboats like (I think) Bowmans, but I have not heard of problems with more recent high-end boats with cored hulls. I think that technology has improved -- with new foam core material which do not absorb water, and fully encapsulated balsa blocks which do not absorb water. On the other hand, since these techniques are relatively new, perhaps boats made with them haven't been in the water long enough to know.

For a contrary view, this guy is pretty passionately anti-hull coring: Cored Hull Bottoms

Here is a story about problems with Morris cored hulls: Morris Yachts Core Repair

[Blue Stocking]

Originally Posted by Dockhead

I don't think whether or not a cored hull will last or not depends on maintenance. I think it depends on the initial build quality and the state of the art at the time the boat was built. There has been a lot of technological advance since the first cored glass hulls were built in the 60's or 70's.

Cored fibeglass has much better strength-to-weight characteristics than solid. Most high end monohulls over a certain size are cored, although monos are less sensitive to weight than cats. I wouldn't want solid glass in a catamaran, personally -- much too big of a performance loss for a theoretical reduction of risk of problems.

There are horror stories about cored hulls in cheap power boats like Sea Rays and very early cored hull sailboats like (I think) Bowmans, but I have not heard of problems with more recent high-end boats with cored hulls. I think that technology has improved -- with new foam core material which do not absorb water, and fully encapsulated balsa blocks which do not absorb water. On the other hand, since these techniques are relatively new, perhaps boats made with them haven't been in the water long enough to know.

For a contrary view, this guy is pretty passionately anti-hull coring: Cored Hull Bottoms

Here is a story about problems with Morris cored hulls: Morris Yachts Core Repair

In all of his examples, the problem did not originate with the core material. It was sub-standard bonding to the cores.
I could show him boats in which I was heavily involved, using Airex mono-cellular foam, as early as 1973, which show no sign of structural weakening at all. Look up "Reef Explorer, Bermuda" 1975 launched.
Dow Corning Polyester resin, hand laid roving and mat.
Build them right, and they will last.

[psneeld]

Do not think fiberglass will live forever.
I am in the throes of chiseling/grinding the gel coat, mat and up to 2 layers of rovng off my 1988 trawler.
The previous owner did a poor job on some blisters but the problem goes back to the manufacture and life of the boat.
It's lived all it's life in Ft Lauderdale in a warm canal except for trips to the Bahamas for up to 3 months a year.

I have extensively researched this issue and the new to me info was ALL fiberglass boats were experiencing hydrolysis, some faster than others, and in the "all" category some had blisters of various levels.

If you don't believe me, read up. And reach out past just boat info...look at the writeups in the composite pipe and tank industries.

There are a variety of reasons why hydrolysis varies so greatly in different boats...but as I found out the hard way....until I took a grinder to the glass around a few random blisters and got down below the gel coat and the mat layer underneath..neither I, the previous owner or the surveyor had a clue.

[lorenzoSF]

Mmhm, so what would you guys recommend?

Dockhead and Blue_stockings, what would be your recommendation on how to make sure the build quality is right?

Psneeld, can you send some links on hydrolysis? If the "life of the boat" is important, what life should she live? Are you implying it should not be left in warm water 100% of the time? That was more or less my plan, cruising in warm places most of the time, so I'd like to know if it is a problem.

Lorenzo