Spanish Cedar Hull....lapstrake/copper rivets....

[Norske3]

....anyone build one? smile.gif

[Thad Van Gilder]

I have used spanish cedar planking on a crossplanked bottom, and found it to work similar to aramatic cedar, of which I have used for clinker planking.

kind of stiffer than the white cedar I usualy use for clinker boats.

I don't see any problem using it.

-Thad

[Uncle Duke]

Maybe I'm remembering wrong (at my age anything is possible...), but wasn't Spanish cedar mentioned in a recent WB article about someone building a very nice 8-Meter?
I don't have issues near to hand, but I think that there was some mention about it being lighter for the same strength, but also something about the dust being 'toxic'?
Do any of the experts here have insight into that?

[Thad Van Gilder]

a lot of good boatbuilding wood dust is toxic!!!!

[Stephen Hutchins]

I've never planked a hull with it, but have used it alot as framework for lightly built interiors in glass boats. It is quite brittle compared to white cedar and I'm guessing more suitable for use with epoxy glue. I've been thinking alot about the different types of construction for small boats, and am convinced that classic designs, built in the traditional maner, but with epoxy in the seems as well as encased about the parts, will give the most value to the owner come selling time. Brion Reiff, of Brooklyn, Maine builds some of his boats this way, one being a restored Fife 6 meter. These boats have all the beauty of the originals, and I believe will require less maintenance in the long run.

[Thad Van Gilder]

But properly covered in epoxy, the life of the boat is reduced quite a bit. So, it's minimal maintenance for a shorter amount of time.

personally, I'd rather have a boat that will outlive me.

-Thad

[Stephen Hutchins]

Thad Van Gilder: "But properly covered in epoxy, the life of the boat is reduced quite a bit. So, it's minimal maintenance for a shorter amount of time."I dissagree with this statement. What makes you think this?

[Thad Van Gilder]

From fixing epoxy encapsulated carvel planked hulls!

Epoxy does wonders for plywood. It does an awefull lot of things really well, but it does not seem to be the cat's meow for a traditionally planked hull. Time and time again I have seen the cracks along the seams and keel. It has nothing to do with moisture percentage. Wood, like nearly all solids, expands in the sun and contracts in the winter. The epoxy can argue with the forces of expansion and contraction for a while, but eventually, the wood will win and the polymer will lose.

Many people have argued against me on this one. After all, epoxy does so many things well. However, this is the real world, and nothing does everything perfectly. Epoxy just doesn't hold up in that use.

-Thad

[Stephen Hutchins]

Were the hulls you fixed properly encapsulated? If the epoxy coat is thin enough, I could envision this (cracking at the seams)happening, but what difference is that from paint cracking at the seams? If using epoxy helps keep a hull from working the fasteners, the hull will last longer. Even if the epoxy does crack at seams, and salt water does get into the wood, this will not rot the wood any faster than on a traditional, red lead painted boat. (Under normal, northeast conditions and care)

[Norske3]

This has always bothered me....wood wants to breath...keeping the cells healthy and allowing it to suck up water..as everyone knows....epoxy tries to smother and keep it from moving...eventually the cells die...the wood loses its strength...brittle and breaks.

[ 09-19-2005, 08:05 PM: Message edited by: Norske3 ]

[Thad Van Gilder]

yes, this is with sufficient coats of epoxy.

Although I have seen problems below the waterline, many have been above, so that it is rainwater getting in to the planking.

-Thad

[LazyJack]

....wood wants to breath...keeping the cells healthy and allowing it to suck up water..as everyone knows....epoxy tries to smother and keep it from moving...:rolleyes:

Breathe Schmeathe!

THE WOOD IS ALREADY DEAD. Roots and leaves that sustained it are long gone...and dead things don't WANT nuthin'.

If epoxy does anything malicious, it traps moisture in the wood creating a nice moist environment for micro organisms that do WANT to eat DEAD moist wood. If a good coat of epoxy applied appropriately over thinner pieces (thin means not thick enough to generate the forces neccessary to fail the epoxy coating) does keep the wood stable (ie. not moving) and dry, why is that a 'bad' thing? Who wants their timbers getting soaked and movin around all over the place? But then there are other coatings that would do the same thing just as well...like paint or varnish which are no more permiable to moisture than epoxy (coating thickness being equal)

Epoxy coating on a carvel hull...makes no sense whatsoever to me. I might try using something like...paint!

[ 09-20-2005, 06:08 PM: Message edited by: LazyJack ]

[LazyJack]

As I re-read my response I'm afraid I sound like I'm flaming Norske3 and I totally dont mean to do that! Its merely my response to theories which anthropromorphize inanimate objects, and the need for wood to 'breathe' or that wood has 'life' is a common sentiment that strikes me as merely an emotional projection and nothing based on rational thought or science.

Forgive me redface.gif

[ 09-20-2005, 06:26 PM: Message edited by: LazyJack ]

[Bob Smalser]

Wood doesn't breath like a critter with lungs does, but it certainly does pass water vapor in and out to reach equilibrium with seasonal humidity. Hence seasonal moisture content changes. This includes plywood.

Epoxy just seems to slow that process down to a higher degree than paint does, but not so excessively (Bondo comes to mind) that the wood rots quickly when moisture does get in. If CPES really does extend the life of varnish on new wood, it's because the wood moves less than with varnish alone. If it's old wood with some incipient decay present, I think a thicker epoxy application than CPES could shorten its life compared to paint alone.

[ 09-20-2005, 06:48 PM: Message edited by: Bob Smalser ]

[LazyJack]

I'll certainly buy that line of reasoning

I applied two coats of epoxy to the outside of my guideboat before applying the varnish (three coats down, two to go)and I'm at a bit of a loss to explain why I did that instead of using varnish alone. I did it partly to build up a thicker film quicker...but I still have to add five coats of varnish at least for UV protection.
Whats more,I didn't apply any epoxy to the inside of the hull, I used just varnish...the logic? Well it escapes me... but it just felt right at the time. Maybe its because I think that epoxy is harder than varnish and will provide better protection from the inevitable rubs dings and scrapes that could injure the soft pine planking...I dunno :rolleyes: