Is Balsa really that bad ??

[Stumble]

LOL and drink more rum.

[masalai]

Harumpf, and another serve of scrambled eggs for the captain, as he seems to have coughed at the wrong time and coloured the forpeak of his cap and the shoulders.... Harumpf Harumpf Kkkkoooiiiiptong-tong ahhhhgh that be better - Two bells is it? - - Aye, another tot O that liker squire....Aye...

Good Sport, G'nite.

[Boston]

after a long good read including all the links
Im cured
and mine will undoubtedly be
a traditional build in wood
no plastics no sandwiches no minimum wage help involved
wow
and I thought I knew why I didnt like plastic boats
yikes
what a nightmare

wood wood wood
and to top it all off
it floats

Boston, I've a plastic boat since '84. A boat with a soul that has soon raised three wives and four kids, carried 30,000 passenger bent on cutting cheese on every surface, vomiting in every corner, dragging 74qt. coolers of beer and ice over every piece of teak trim, and with nay a whimper.
But I, too, long for the warmth and character of a wood boat I experienced in my youth. One day...

[Manie B]

My 2 cents

epoxy and glass over marineply is most certainly within the reach of the average amateur boatbuilder

its a little bit like me

he he

strong - stiff - and "rigid"











the part about epoxy over marineply is true

[Boston]

that was really well said Mark
I guess my prejudices were pretty well rooted and then I read those three articles
it just kinda lit a fire
I new they were having troubles with the stuff but had no clue how severe they really were

Im ordering a few thousand feet of black walnut for a custom porch, entry foyer, door and staircase with turned railings
so I guess I've the privilege of working with wood all the time, maybe sometimes I forget what a privilege it is
I really didn't mean any disrespect towards those who do own well built cored boats

raises three wives ? my god man what were you thinkin
Im betting you started with just one and simply forgot the rules
keep them out of the light
do not feed them after dark
and never
ever
give them any water

[P Stuart]

Guys, I agree with Dereck only only on spec and all of you seem to have the same opinion and so does he really - just a different way of saying it. Build it right and use the correct techniques.
In my opinion all wood laminates should be totally encapsulated in epoxy as its not porus - that is the problem with polyester, gelcoats and unsealed primer coat paints.
Also if you are going to use wood laminates extreme care should be taken to design the structure in the corect load sense. Plus it requires protection from damage either mechanical or structural.
Vacuum bagging is an extremely eficient way to encapsulate the Balsa in epoxy resin.
I will qualify the argument by telling you of the build of my yacht an its problems with Balsa Core over the years. First off the yacht has had a hard race life being an Admirals Cup One Tonner of 40ft and being completely vacuum bagged and built from Balsa Core, Kevlar, Foam and Epoxy Resin in 1984, and to date no structural failures or even any cracks, one suspect crease, which turned out to be a paint line from a piece previously fitted.
The decks are a laminate of Balsa, Kevlar, Glass and Epoxy resin. The yacht in question is almost 25 years old and the only repair we have needed to make (so far) is a core replacement under a deck block, where the core failure was caused by mechanical damaged to the deck block from an item hitting the block and breaking the decks through deck seal allowing water into the core.
The time period to when we found the problem is unknown but I suspect at least 5 years. the core structure was reduced to what I describe to people as wasps wings (anyone who has seen it will know what I mean).
The block was removed the damaged areas deck was cut and lifted (an area of 15 by 8 inches approx), core replaced and epoxied down and vacuumed. all took about 4 hours - not including curing and refinishing etc.
Carrying out the repaires looks just as brutal as duing a strip plank repair, but I think with the right equipment and techniques and not being afraid to tackle such problems that its quite quick and relatively simple to repair.

[masalai]

Boston,
Have I seen that advice in a movie featuring cute little animals with big loveable eyes? who turn vicious when the rules are broken? - - I do not think those rules apply to those who become wives.... although their demands seem similar to that required by boats

[Boston]

well ya
I think it was called "the dating game"

Ive seen the bewildered and shell shocked look some of my buddies get shortly after they get married and start
feeding there wives

an old Chinese man once told me the rules
and mind you Im not superstitious
the Magui is a gift
a great responsibility

and then he mentioned that little set of rules I noted

so far it works for me
trick is do not overfeed em

[barks]

Balsa has all the best properties for boat building except 1. If you can overcome this then it is fine. Unfortunately it acts like a sponge in contact with water and will need digging out and replacing it if after contact with H2O. You will enjoy its higher performance characteristics while it is dry and all who praise balsa have been successful in doing this.

[Boston]

anyone tried encapsulating it in shellac and seeing how it behaves as a primary building material

I guess what Im driving at is
could it or maybe some of the other lightweight materials typically used in say aeronautics be applied ot yacht construction in a way similar to a traditional wood build but
if engineered up to standard also serve in a duel role of both structural components and flotation
one thing balsa wood does really well is float
its also reasonably strong for its weight
as is spruce
soooooo
if various members of a traditional wood hull were sized accordingly and properly encapsulated would something like balsa or spruce which both have at least some rot resistance
be used as the major components in a yacht build
minus the plastic
with the planking in say a double diagonal configuration rather than some kind of fiberglass, core or not
just a thought
but wood that breaths tends not to rot
would that is buried in a plastic bag and subjected to water
rots

ps
if this is to far off subject please pm me your response so we can keep this one on track
I learned a lot from this thread
would be a shame to see it twist away from its original topic

[PAR]

Balsa's sole role in these types of laminate is to offer it's very high compression strength to weight ratio, within the sandwich laminate.

Boston, these engineered laminates (sandwich construction with a balsa core) are very different then the structures you are accustomed. They bear little resemblance to things you've seen or understand. This isn't a dig, it's just that most people have a hard time understanding these types of material combinations.

[BeauVrolyk]

I own a balsa cored boat that was built in 1980. It's called a Moore-24. There were a little over 150 of these boats built between 1976 and 1984 or so. Almost all of them are still sailed and raced extensively. For example, we regularly get over 40 boats in a race. This construction technology was also used by a number of other boat builders in Santa Cruz with very good results long term.

While some of these boats have had water get into the core, it has always (to the best of my knowledge) been caused by the owner/crew drilling a hole to mount a fitting and not properly sealing the hole. It's easy to fix with a drill, heat gun and penetrating epoxy, much easier than wood.

I also own a plank on frame wood IOD from 1946, all wood all the time. Having maintained both boats for a while, I have to say that the Moore is a MUCH better boat with regards to durability, strength, weight, and endurance. As much as I love my old IOD, there is simply no comparison. I have re-planked, re-bedded, re-everything on the IOD and as much as I love the wonderful smell of the wood, the great feeling of working with wood, and the look of it, it is simply not anywhere near as good a material as a glass/balsa boat. Not as strong, much higher maintenance costs, much more fragile; while the problems are a little different on the wood boat, they're much more numerous and severe.

Finally, there are poorly built boats of all types and one shouldn't judge the characteristics of a construction material and technology on the basis of examples of badly built or mistreated boats. It is trivial to find bad examples of wood, glass, steel, alloy, you name it. If one compares well built polyester/balsa boats with well built boats of other technologies, one will find that typically there is much lower maintenance cost and much higher performance from the poly/balsa boat - it's the reason there are so many of them. My boat, at 29 years old is a pretty good example - not one soft spot anywhere. One does have to know how to treat the material, just as one needs to know the same thing about wood. No material can withstand an ill-informed or careless owner.

Beau

[Boston]

no Im ok with that
Ive never really worked with the stuff (fiberglass is a complete alien to me )
so all I know is what I read and see when I occasionally make it back to the water ( about once a year if Im lucky )
what Im reading and hearing is that if your dam careful as an owner and were lucky enough to land a good builder you could end up with a good boat
baring any materials defects like some of the ones discussed in the articles presented
which are apparently more common than the industry lets on
thats a lot of maybe's which leaves me inclined to lighten up a wood structure rather than go with composites

things like those articles kinda sound spooky from the perspective of a life long woodsman
sounds like more of a crap shoot than an informed decision
wood I can feel it
check its grain pattern
sound it or smell it and tell you if its good to go
and the best part
it floats

reason I ask is that a laminate is a laminate
layers of stuff
Im about to laminate a front door together out of white oak and black walnut (raised panel front door for that black lacquer job I may have mentioned )
course thats got nothing to do with fiberglass but still
the strength and consistency imparted by the layering process I got down
its the particular material being laminated that Ive no experience with
fiberglass or composites cored or not

so you hit the nail on the head

that said
has anyone successfully built a yacht predominantly from laminates of strictly the lighter wood materials ( no fiberglass )
like say Sitka Spruce ( one of my faves )
that stuff is seriously strong and lite
relative to its density
or balsa maybe a third the weight and Ild have to look up how it stacks up in terms of strength
seems like it would make a strong light structure
obviously with segments laminated to impart the strength needed for certain components or certain areas
or even just a complete cold mold