Thread: Coquina

In these twilight years it takes a lot to bring a tear of joy to the cyclopaean and jaundiced eye of the barnacle, however you and the redoubtable Dr. Hylan did it for me with the pics of Coquina's lovely bottom which capture the simplicity and beauty of Nat's eye for that magical zone within which wood and water move against each other.
Although some great small boat draughtspeople, Strange, Mower (on a good day), LF, Ryder-Turner, Bolger in gold plater mode and many more down to our own National treasures Payne, Peachey Storer et al. have drawn lines of fabulous beauty, Nat's lines refer to and derive from nothing but the spring of clear timber and the weight and embrace of water. Nat's oeuvre was completely free of the bonds of tradition, fashion and the admittedly enjoyable, but none the less derivative, architectural diversion of recreating the perky workboat styles of the past.

Anyway thank you!

The barnacle as you know can be a damnably garrulous arthropod and I'm afraid there is more:

In his dotage the Barnacle occasionally carries out small maritime experiments trying out some of his own and others thoughts about what might be good in tiny boats. A recent experiment (inspired of course by the tempting Coquina) was to try out the endless rope steering on a particularly headstrong and ornery sailing canoe in the posession of the Barnacle. Despite earnest consultation with Skene and others, the first high aspect semi balanced rudder blade laboriously carved to NACA whatever proved too small in area for what is in all honesty a bit of a lump of a canoe and definitey too small for the hurricanes that bom is pleased to call afternoon sea breezes. In the end another model scaled up by two thirds again was grumpily and hastily prepared and tried, this time with truly magical results.

I wanted to pass this on to any Coquinophiles who still have any doubts at all about whether rope steering is as simple and intuitive as tiller steering and whether you still get the tiny changes in "feel" through the rope that connect you so intimately to the boat and its passage through the wind and water. After maybe 8 or 10 hours of "flying by wire" including a nerve wracking run before a 20kt Northerly in one metre waves from the black pole back to Garden Island, I have to say that in the first 10 minutes of steering, helm adjustments with either hand became completely intuitive, even taking into account that with a high aspect rudder at speed, helm corrections are extremely small maybe even 5mm. This is curious because in my system and certainly in Coquina's as drawn there is at least 5mm *(probably more because of the geometry of the connections direct to the rudder blade) slack in the lines to allow free movement in the blocks. I used spectra line which has a certain stiffness and it occurs to me that it feels similar (with respect to is stiffness) to the manilla line of similar diameter (about 8 mm) which was pobably used on Coquina the first. Maybe this stiffness permits greater sensitivity at less tension than would be the case with the more usual polyester yacht braid.

Do not despair dear friend, the Barnacle is almost finished - there remains one tiny matter to deal with. If any Coquinophile is silly enough to have a canoe or kayak in need of a small rudder or knows someone who does, there is one here they are welcome to inherit. It is 800mm deep, 200mm chord width reducing to 80 at the tip and is made of 2 laminations of 9mm hoop pine and a core of 12mm okoume plywood sheathed in 200gsm cloth and epoxy finished to trade rather than yacht standards. It has built in gudgeons in the form of an aluminium tube buried in the laminations and a T head for steering lines but would need pintles of some description. For a canoe or Kayak I use a tilt up mechanism hinged from the deck, held down with shockcord and raised from the cockpit by hauling on the steering bridle itself which works very well for me. Let me know at [email protected]

Originally Posted by Mr Barnacle

Anyway thank you!

You are most welcome kind Sir.

The barnacle as you know can be a damnably garrulous arthropod and I'm afraid there is more:

The only observation this poor unedjumacated boat builder can offer is your expansive posts causes one by necessity to improve his vocabulary.

I do appreciate your knowledgeable additions to this thread.

Originally Posted by rob540

Truly beautiful work Mike, she's just gorgeous.

Again thankyou both for your encouragement.

No gains in the stern?

G'day Paul,
I'm having a bet each way, jogs combined with a small gain to decrease the chunky look.
Pics of one of the builds with Doug Hylans plans shows stern gains in ply and apparently there was some difficulty at the turn requiring the planks to be hollowed something I was reluctant to tackle, plus I quite like the look of jogs.

I've added my favorite pic of the boat so far don't know how I forgot it in the previous post.

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It's common to not have aft gains at the turn of the bilge for this reason (the twist). I usually force the issue with a rolling bevel, which addresses the twist issue and some backing if the planks are wide, which usually they aren't at the bilge turn. I suspect old Capt. Nat had a trick for this, but I've never seen a HMC built lapstrake without gains aft.

Originally Posted by PAR

It's common to not have aft gains at the turn of the bilge for this reason (the twist). I usually force the issue with a rolling bevel, which addresses the twist issue and some backing if the planks are wide, which usually they aren't at the bilge turn. I suspect old Capt. Nat had a trick for this, but I've never seen a HMC built lapstrake without gains aft.

I fear this wood butcher is unlikely to try.

Actually now that I have cut some gains delt with the transom bevel and cut the jogs I'm inclined to think aft gains and for flush planks would be easier than the way I've approached this task. What swayed me to jogs was the build pics of the first Coquina John Brooks built in ply showing jogs rather than gains. He then built a second boat in cedar with aft gains.

In fact having nearly jumped this particular hurdle and while I'd hardly suggest the job so far has provided me with sufficient experience I feel an urge to try a traditional build with proper wood and fastenings.

The thing that still intrigues me is how the transom to plank joint does not leak without the trusty pox, sure for the laps some swelling of the wood does the trick but at the stem and transom it's a different story with end grain etc. to contend with.

Lots more to do on this boat so we will see whether the urge still exists at completion (a little 10" dinghy would be fun though). I'm thinking a certain member of the family may well raise objections to such a plan.

I've cut many a gain in solid timber stern planks and it's a challenge. With glued seam, you can literally just hack the plywood to shape with a hatchet, a little goo and putty and you're good to go. Not so with solid timber and traditional laps, which must be perfectly fitted or it'll leak. I've tried decreasing fastener spacing to solve this issue at the stern, but only good fits works reliably on solid stock. It's rewarding work once you figure out how to do it. I use the dory lap rather then the ramped and rabbited gain often seen. The dory lap is much easier, though it's a rolling bevel which takes some getting use to.

I needed to look up dory lap, that is what John did on the cedar Coquina as in the upper plank has a constant bevel on the inner edge and the lower plank has a rolling bevel to suit the hull shape. This differs slightly in the way Greg Rossel describes it in that the constant bevel is on the outer edge of the lower plank.

Things have been progressing and I'm ready to hang the final plank #11 then on to the sheer.

A thing I realised this week is I've been doing the gains all wrong. I noticed they should be halved on each plank whereas I've just cut all the gain on the previous plank ending flush at the stem. Oh well I don't think it should make much difference.....I hope.

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I was standing in the shed today admiring my handy work when it suddenly dawned on me I should have dry fitted and drilled the stem before all the planks went on otherwise it would be difficult to clamp in position. Hmm fortunately one clamp at the top of the stem was enough to get the job done.
So after much umming and arring the stem was drilled, countersunk and screwed into position. There will be a little fairing to do but I'm reasonably happy with the fit.

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The over length on the keel has been annoying me for weeks so today a bit of surgery removed the offending appendage.

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After again standing back to admire the days outcome I couldn't resist starting the bevel on the stem rather than hanging the final plank, that can wait for this week.

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I received a package from the US sent by Jim Reineck containing some nice bronze bits for the rudder and a stem fitting.

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That's it for the minute I'm looking forward to shaping the sheerstrakes although cutting the expensive boards will take plenty of nervous consideration.

In the photos I have from Doug Hylan there is one of cutting the sheer from about a 12" board and on the pattern Doug wrote "There is not greater calling for a piece of Mahogany wood than a Herreshoff molded Sheerstrake".........nice.

Looking terrific . I look on in admiration...what more can I say?

Cheers,
Alex.

Looks like a boat!

Originally Posted by Groggy

Looks like a boat!

It must be a boat then

Originally Posted by AlexN

what more can I say?

Plenty of time left to think of something Thanks for watching Alex.

Hi

I built a lapstrake Coquina following Doug Hylan's plans and using Reineck parts and it turned out to by a very nice boat to sail.

With the sheerstake I cut it out directly from Doug's plans and it went on fine. It is a lot stiffer than the ply strakes of course and needs to be pulled in but all went fine. And I put a small coaming piece to join the side decks and the sheerstrake. About 3/4 inch by 3/8 inch set inboard from the sheer strake and sitting on top. The cockpit coaming is heavier and is about a 2 by 1 inch rebated to accept the deck into it and to stiffen.

I having been sailing the boat all this year and it is a great boat to sail, surprisingly fast given the age of design and reasonable pointing with the swing board and the gaff rig. The rope steering to me is not intutive even after 50 years of sailing but quite OK especially as when pointing I use the mizzen sheet to steer. Hope you get yours in the water and sailing shortly although from my experience sailing at places like Glenelg will be on the adventure end of sailing.

Hello wizened and welcome to the forum.

Thanks for posting your experience with the sheer and I'm glad to hear you are enjoying Coquina. I'll be sailing down around Goolwa in the lakes even so I'm considering some extra buoyancy.

I wonder how many builds there are in Oz could be enough for the Coquina Nationals.

OK now that we know you are here a thread of your build will be greatly appreciated (lots of pics of course we like pics).

Cheers