First, a bibliography of boat fix-up books.
Yacht Craftsman's handbook , Garth Graves
Boatbuilding, H. Chappelle
This old boat, Don Casey
Boatbuilding Manual, Robert Steward
Sensible Cruising Designs, LF Herreshoff (The how-to-build sections)
The Gougeon Brothers on Boat Constuction

You'd assemble the thing in one swell foop. Counterbore so the nuts can be covered
with bungs, then drill the holes for the cross-bolts a bit oversize. First, assemble
it dry , to make sure things are aligned OK. Then, take it apart, cover the room with
plastic film, banish the dog, mix your epoxy with a little thickener [WEST #403,
milled cotton, 'flox', all the same], anoint all parts liberally with the epoxy mix,
assemble it and tighten the nuts only gently.

You might also float an inquiry on the message board of the CD 28 powerboat group

orbital wrote:

I'm still convinced that cross-bolts are needed here. The several
descriptions in my boatbuilding books of the construction of bow planks all
specify cross-bolting. There will be times when this plank is very heavily
loaded, like when you run the boat into something large and immoveable and when
the boat is on the anchor/mooring in a storm. The Cape Dory 28 is too good a
boat to lose to half-baked 'improvements'.

Can you recommend a good book for me to pick up that details the
construction of a bow plank or pulpit? I certainly want to do it
right. That is exactly why I appealed to this group for advice.

Jamestown and others have SS and bronze threaded rod. I'd do maybe one 5/16"
cross-bolt per foot of plank length. Counterbore for the ends of the
cross-bolts and bung 'em. The rods will be a big help in aligning and clamping
the assembly. For appearance, use epoxy, not resorcinol. If securely bolted, a
non-impervious finish is OK. If not, moisture will gradually open the glue
joints.

So, this would mean that I would have to glue up all the pieces in one
shot as opposed to a few strips at a time in order to put nuts on the
ends of the threaded rods, tighten the nuts and clamp it all?

I think I am pretty convinced that Epoxy is the way to go for this.

If you insist and are expecting cross-grain strength from the dowels, don't use
the grooved ones. The groove significantly reduce the effective diameter of the
dowel. Instead, just plane a flat into the side of the dowel before cutting the
dowel up. That'll allow the excell glue and air to exit.

I have actually had been leaning towards using bronze wood screws to
line up and attach the wood pieces while glueing over pegs. I was
wondering if this would give the lateral strenght necessary.

The geometry of anchor rollers is sometimes hard to figure out. I suggect that
you get the anchor and make a propotype plank with 2x construction lumber to see
if the anchor clears the stem by just enough.

Have you contacted the builder for his recommendation? Andy Vavelotis now owns
Robinhood Marine in Robinhood, ME.

This is a good idea and I have sent out some emails to see if I can
get some feedback from them.

Do it right,
Jim

RG wrote:

It has been stated clearly here...but I would re-iterate it...If you use the
dowels method..be CERTAIN that you use the GROOVED dowels. You need the
groove to allow the excess glue a chance to get back out of the holes. I did
a project once, and used regular doweling material ( non-grooved) and
puzzled forever why I couldn't camp the material easily. Seems like
something was forcing it apart. It was the excess glue trapped in the bottom
of the glue holes!!!

RichG

You want a closed slot or some other hardware to capture the rode at the
roller. Otherwise, any good breeze at anchor will pull your rode off the
end of the sprit and hang it on your pulpit rail or stachion. All
surfaces the rode may contact need to be smooth (and abrasion
resistant). Epoxy deteriorates in UV (sunlight); good tight seams may
mitigate this, but OTOH, epoxy likes fat seams. Hence you may want to
consider UV protection for your seams, or use some additive in the glue
to reduce UV problems.

I bolted together a bowsprit this way with epoxy; I use cetol on it to
protect it. However, I think 1-1/2" epoxy laminate without rods would be
strong enough if the glue-up was done right. Usually epoxy joints are
stronger than the wood. Your main issue with simple (proper) glue-up
would be delamination due to wood movement (wet/dry, hot/cold,
top/bottom). Email West Systems with the approximate specs for the
sprit, its roller assembly, and the attachment method on the boat. From
what I hear, they're quite helpful.

When drilling for "through-bolts", you want a pretty tight hole to
maximize lateral support from the rods. You can use a drill to drive the
rods in (couple clamping nuts on one end and/or a little dab of epoxy
under them). You can use the dowling jig to drill the rod holes - all
the way through each piece. You want the countersinks on the outside
pieces to be extra large with flat bottoms to accomadate washers. If you
drill these countersinks first before drilling the rod holes it'll be
easier to center them with the rod holes. You can use a cheap (sharp!)
paddle bit; a forester bit would be better if you have one. I used
polysulphide to fill the holes rather than bungs because I was using
1/2" rod with 7/8"OD washers and the resulting bungs would have been
over 1" - seemed a little flakey. Also, the nuts and washers were more
than 1/2" thick and I didn't want to drill the countersink deep enough
to accomadate both the nut and a thick bung. Also based on vast past
experience g I wasn't sure I wouldn't be back in there someday. The
poly "bungs" show, but not too much with the cetol coating.

If the anchor sprit gradually narrows at the forward end, you can build
the sprit "square", then cut the taper. Calculate how deep to drill your
countersinks based on how much the sprit narrows. Grease the rods
affected so you can remove them after glue-up and cut the taper into the
finished sprit - then reinstall the rods.

How you mount the sprit is also worth serious thought. Anchor forces can
get pretty large both vertically and horizontally in a blow, with the
force catelevered off the bow so it's potentially multiplied several
times at the point it's connected to the boat. You can reduce this issue
by making the "onboard" end of the sprit as long as feasible. However,
you also want to be aware that when you hit something large and immobile
with your sprit, _something_ will give - and you probably would rather
it not be the hull. You might mount the sprit with bolts on deck which
will leave relatively small holes if they rip out, or you can reinforce
the hull/deck to the point the the sprit will fail first. Designer type
people actually can calculate the fail points for materials, but that's
not my area.

Rufus


orbital wrote:
I have decided to completely forego the light on the tip of the
pulpit. It seems that it will add quite a bit of work to the project
regardless of the approach and there is some question as to how it
will affect the overall strength of the finished piece.

Instead, I will add sidelights to the flybridge. They will improve
the visibility in that position as well. It just means that now I
have another wiring project to get done this winter.

The other thing I am now contemplating is if I should forget about the
slot in the pulpit. I was going to use the slot so that the anchor was
stowed under the pulpit with the rode coming through the slot and into
the windlass. Now I am thinking of using a roller on the top of the
end of the pulpit so the anchor rolls of the front and stows up front.
Again, this will make the construction easier and keep the acnhor
further out from the stem of the boat.




It does. However, how about a compromise? You build the part full
thickness and then dado a 1" wide by say, 3/16" deep trough down the
middle, on the underside of the part. Centered in that trough, dado
another trough wide and deep enough for your wires. Set in the wires
and fasten a 3/16" by 1" "cover" into the initial trough, flush with
the bottom. It would be easier than the layup schedual you have in
mind for sure. I don't like the odds, clamping the parts the way you
have suggested, leaving a blind conduit in the part. I think my way
would be stronger too, as well as leaving access to the wires.
Scotty, recovering ascii junkie...

Oops. Used polyUrethane.

Rufus wrote:

.... I used
polysulphide to fill the holes rather than bungs because I was using
....