choice of finish/ choice of lumber

Opinions, please;

Contemplating construction of hull #5; 16 foot
flat-bottomed skiff of "instant-style" construction;
i.e. plywood with exterior chines and a minimum of
framing. Chines, gunnels, and what other framing
there is almost exclusively 1 1/2" by 3/4' (finished
size) wood strips.

I have obtained locally some Occume BS 1088 1/4"
for the sides of the hull. Bottom will be most likely
1/2" marine fir as I can not locate BS1088 in 1/2"
locally. Occume will be covered with epoxy (no cloth)
inside and out and edges. Some areas of the Occume
will be finished with paint; some with varnish.
Fir bottom panels epoxy and Xynol on
outside.

Questions: What finish for the inside of the fir bottom.
In order to do a neat job of glassing, bottom panels, which
are fitted to the boat (not pre-cut) would have to be
temporarily fitted and cut, then removed and glassed,
and then refitted. Can the fir bottom be installed and given
an oil finish on the inside and be expected to hold-up?
There will be "duckboards" of sorts (actually cheap colored
plastic lattice cut to shape and thrown in there) so the bottom
will not get too much wear. I have used this lattice
before and like it.

Second question: choice of wood for the 1 1/2" by 3/4"
chines, gunnels, and framing. Would like to use one type
of lumber, and these pieces will all be covered with either
epoxy, or epoxy and Xynole cloth (exterior chines), and
then painted; or epoxy and varnish (finished bright).
What kind of lumber could be used that would be suitable
and would not be too dear to the pocket book?

Third question; the gunnels are doubled-strips of 1 1/2"
by 3/4" lumber; would like to have an inner layer of the
lumber from question #2, plus an outer layer of something
darker, posibly some type of mahogeny or maybe Spanish
cedar. Both laminations of the gunnel would be coated with
epoxy and finished bright.

I don't really need this boat to be a piece of woodworker's
art (I aint no artist) but would like it to have longevity
and a simple elegance that is somewhat lacking in my
previous work.

Opinions?

 

I would study how they build those River Skiffs they pound the waters with in Arizona and Colorado,seems River Dories are advertised now and then in Wooden Boat,I'm sure you could dig up some info in no time.As far as framing lumber is concerned,stay away from Fir,it splits too easily.I prefer White Oak or mahogany.Build the thing and then use Interlux Bilge paint,it stinks while applying it with your nose down there but I like it.The only "oil"type bilge coating I like is Sikkens Cetol,use a respirator,this doo-doo has Creosote in it!I love Spanish Cedar,but it may not hold up for the gunnels.3#rd grade Mahogany would be better.

 

This is what I cal a furring strip boat. All the framing and structural details are 1 x 2 (3/4 x 1 1/2)

I wouldn't go crazy with the epoxy and sheathing on this, just the bottom or the both bottom and top side planks. It sounds if this is to be made simply and inexpensively, you sound like you want to keep this element and this is good.

Doug. fur plywood doesn't look good with a "natural" finish, the logs are cut wrong for the grain to look nice. Personally, I don't think oiling plywood is a good idea, because you basically swelling the outer layer, asking the glue line to like it, for the sake of a natural finish. Varnish or poly would be a better way to go, over epoxy if you like as the fur will likely check with age, if you must have the bright look. I'd just paint it myself, less cost, trouble mess and easier to repair.

Your "gunnels" will also serve as you rub rails and should be of tough stock. There are a number of hard woods that could serve here, the choice is governed by rot resistance, workability and availability. Since you want to use a 3/4" lamination of this stuff, I wouldn't trust white oak. White oak can be epoxied, but only in thin laminations with special attention to the process. If the piece was solid oak (no lamination) this would change my tune as it make a good gunwale, rub, breasthook, etc.

Ash, cherry and black walnut all have reasonable rot resistance and fairly dense, making for good rail material. Mahogany has moderate rot resistance and isn't as tough as the others listed, but can be quite pretty. There are a number of different types of mahogany, some not even real mahogany.

Lumber is locally specific, meaning what is available reasonably here may not be there. The local builders and sawers will have a good idea what's useful in your neck of the woods.