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Bruce in Bangkok[_2_]

On Sat, 1 Dec 2007 09:47:31 -0800 (PST),
wrote:

On Nov 25, 8:08 am, Tom Francis wrote:

OK, I had actually sent this to the origional poster (we are friends)
but wanted to let the builders here give their opinions first. I
should note that I had a little better idea about what the OP is
looking to build.. Anyway, for the sake of anyone else following the
thread, here was my response to the post

SNIP
On Nov 25, 8:08 am, Tom Francis wrote:
A few years ago, I purchased some mostly clear pine boards - 24/28
inches wide, 12 foot long and 2 1/2 to 3 inches thick. I was planning
on using them for another project, but that project went a different
direction.

I got to thinking that a good use for the wood would be to build a
boat. I've always been interested in building one - dory style
lapstrake flat bottom center console with an outboard motor well. My
Dad had a boat which was 18' and built similar to what I'm thinking
about - it might be fun to build a similar boat. So I have a few
questions.

How thick would I have to have the boards resawn to for planking? I
tthe pine even suitable for this type of building?

Clear pine with knots smaller than 3/4 inch could be resawn to 7/8 of
an inch and would traditionally be used as bottom planking. Pine does
not have a lot of other places in a boat like this, it does not hold
fasteners well, or stand up to water well either over a prolonged
exposure and it "walks" a lot with moisture change. Initially it was
used for bottoms as it was soft and would wear down, and then it was
easily replaced. For a wet tender it might be ok, but a traditional
pine plank bottom would need to be soaked to get sealed up and that
would not be practical. And before you ask, glass or even hard
adhesives will probably not last long with the way the pine will move.
Having fished with you, I know you like to wear sneakers so in my
opinion you would probably be better served by some 3/4 inch marine
plywood, an optional sheet or two of 6 oz glass and resin on the
bottom and a few inches up the sides so you can slide it up on the
beach.

As to ribs and stringers which would be the better choice - white oak,
red oak or hard pine?

White Oak is the traditional material reccomended by North East old
school designers. It holds fasteners well and stands up well to water.
The downside of white oak is if you are using a more modern adhesives
along with your fasteners. White oak has an oil that requires special
attention, and labor. Red oak will also hold screws well but turns
black when exposed to water. Pine would not be used for framing and
stringers, I would not even use it for seats, it would probably curl
up like a pretzel in the weather, plus it is very prone to rot. Option
4 is Mahogany. Not quite as hard as oak but it holds fasteners well,
adhesives, sheathing, etc. It holds up well to weather and damp
conditions, For a standard skiff, no epoxy, John Gardners dories in
this size and configuration call for 7/8 inch white oak, so if I were
to use mahogany I would increase the scantlings some.

As the boat will be flat bottomed (like a skiff), would you build the
bottom out of marine grade plywood?

See above.

Would you consider fiberglass for the bottom after building?

Not the whole hull, see above.

Are the designs of this type boat available for purchase? Or where
would I go to ask to find plans?

Glenn-l.com
Bateau.com
I have a book for you too, I will call you later.

I'm starting here - I'm sure there will be other questions as I
develop this idea more fully.

Thanks for your consideration.

Tom

I would also note that the answers you ge there will not consider the
seating and structural changes you will need to make to accomodate
your interior design. Eliminating the two thwarts will drastically
change the way we approach the "cage". This is not rocket science but
it does need to be addressed. Triangulation, laddering, pretty
straight forward...

Scotty

You do not state the type of pine lumber that you have but if it is a
goodly number of White Pine planks with few knots and any knots are
tight and it is actually in the sizes you state then I suspect that
you can sell the lumber and buy good boat building lumber and probably
still make a profit.

Bruce-in-Bangkok
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from address for reply)