Thread: Coquina

I can vouch for Doug Hylan's plan.
They are very clear and very accurate.
I've got a set of plans sitting in my top drawer at the moment, and their clarity sure does make it enticing to jump straight in and start building.

<i>I have been wondering if I should epoxy coat the cut out transom now or after the planks have been glued or if I should coat inner side and varnish outer, any thoughts.</i>
I'd epoxy seal the whole lot now. By the time you finish planking, a few seasons would have come and gone, and we all know what timber can be like. Recently I was making a coffee table. I decided to Epoxy coat the top side. Within days the whole thing had cupped. I was enjoying reminiscing about the days when all surfaces were flat, and all joins were square, everything was plumb......arrrr those were the days.

Thanks Mick you are spot on by the time I've done with planking many seasons will likely have passed.

This week I started marking out the planks and quickly discovered two things first I needed a 48" square and paint cans, fitness weights etc are not quite up to scratch for holding a batten.

So after casting around I found a supplier who would cut up a bar of lead thus I now have six ducks or whales which ever you prefer but couldn't find a square so I made one using an alloy rule with both imperial and metric marks.

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I'm going to tuck a little admission in here in explanation of why the build is somewhat slow and spasmodic. Up until recently time in the shed has mainly been weeknights as my weekends have been taken up with fishing on my other boat.
It's a Glastron Deck boat about as far removed from a Coquina as you can get.
21' 1800 Kg 200 litres of fuel burns about 50 litres an hour and a noisy great lump of a thing that looks ridiculous with the bimini and clears up but I love it.
Does 45 Knots WOT and rated for 12 POB, pretty useless for anything but fishing and skiing on protected waters but that's what we got her for.
We've packed her away for winter now so some boat building can get done.
Here are a couple of pics from launch day. OK am I banished for posting frozen snot?

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I made another discovery this week.

A fair batten is an invaluable boat building tool. Now this is not new boat building books do recommend a budding builder invest time in finding suitable lengths of wood accurately plane and then look after true battens.

I understand why as this week when marking out the planks all was looking great. I found a couple of my measuring errors corrected same rechecked everything then retrieved my battens from the rack and marked the lines. What looked like fair lines at a cursory glance were in fact quite wobbly when siting down low along them. Checking my long batten that was true 12 months ago I found it had developed a flat spot.

Anyway only about a 1/16th adjustment was necessary in a couple of spots which was allowed for during cutting and as the marking was only to rough cut at this stage no harm was done.

I'm off work this week with the view to cut out some molds and set up the backbone. Well that's the plan but to date a daughters visit to hospital and a mate who was determined to try out his new boat have interrupted the flow........such is life.

Not much to show from this last week except my set up for plank cutting and oh and I did get stem mark 2 glued up.

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Hmm I posted last night but it has disappeared. What a waste of all the quip that I can no longer remember .

Anyways, it has taken longer to set the molds up than I anticipated but nothing new in that. I miscalculated on the number of MDF sheets required and ended up using a mixture of MDF, veneered MDF (bits lying around) and some yellow tongue particle board flooring. The local hardware had some on special and as it is water resistant I figured it should make good mold material it does hold screws well.
Painted them white so tired eyes can see the marks and to make cleaning the pox inside the hull easier.

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Found an error when checking for fair. When marking out station 12 I did not set the bottom edge of the plan perfectly with the edge of the sheet thinking I would trim afterward. Hm forgot about that and went on to mark out the others spot on. Only a 3mm adjustment necessary.

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A this point the workshop is a shambles so a clean up is in order plus I'll rearrange the machines again to gain some wiggle room the table saw will go back in a corner against the roller door to sulk.

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That's looking very exciting.
(must be a relief to have worked out WHY the unfairness crept in.)

Originally Posted by rob540

That's looking very exciting.
(must be a relief to have worked out WHY the unfairness crept in.)

G'day Rob,
Exciting yes and anxious. I keep checking and rechecking levels, centre lines etc. trying to pick up errors.

At some point soon I will need to stop fussing and start on the transom bevels.

I didn't quite get around to the clean up more of a brief sweep then on to beveling the stem. This proved to be a fairly long winded affair due mainly to my somewhat timid approach after messing up the first stem.
I assembled the stem, mast base and hog (inner keel) and slowly developed one side bevel with a #4 then a freshly sharpened block to refine things. There is still a bit of final shaving here and there but I will leave that till after the hog has been beveled and the stem has been glued to the mast base.

Must say I thoroughly enjoyed the quiet contemplation and pleasure of using sharp planes. When satisfied with the way things went I removed the mast base and attacked it with a coarse set #4 in the vice to rough out the shape on the other side of the mast base then refitted to the stem for the final finessing with the block which did speed things up.

I did use a spoke shave at some stages but found the block was easier to maintain a constant angle and controlled tear out.

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Bolstered by success with the stem I've started on beveling the transom and cutting the jogs hmm........much consternation.
Doug Hylan has provided for both jogs in the transom for the plank lands or gains for flush plank ends.
I've chosen jogs thinking it would be easier plus I quite like the look however having cut a few now I think maybe gains would be better, don't know really.

During both the stem and transom beveling stage I have been concerned about checking and rechecking with a batten the angles. I really didn't need to, so far all the marks transferred from the patterns have been spot on.

I find this quite remarkable although I did take extreme care when marking but given some of the acute angles I am still amazed and relieved.

The pic shows the result of several hours of work again I approached this task with extreme caution carefully shaving a bit then checking with the batten however by about the third one I became a little more confident and relied on the marks and took to it with a Japanese saw to rough out the jog before paring to finish. Got quite slick after a while and can finish one in about ten minutes.

The bits of ply (offcuts from the planks) are to confirm the height and angle of the plank overlaps.

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What a great post

Thanks Rob, it does lack a mistake or two but wait there will be more.

I have been wondering about the wisdom of cutting all the jogs in one hit rather than working to the plank lines as they are dry fitted. To counter this I have hedged my bets and left a bit of meat for final fitting, hope I've left enough.

Seriously this stage has proven to be especially pleasant working with hand tools beats playing with epoxy anytime.

Excellent work!!
And its good to see that all is going according to plan.
I'm really interested to see how much of the boat can be built just by using good wood working practices. The less the epoxy, the better.

Hope everything continues to go well for you.


Cheers



Mickj

Cheers Mick, re the use of epoxy I'm grappling with that to a degree.

Obviously the laminated stem and glued laps however it seems our American friends are not fond of coated ply due to puncturing the surface on sharp objects leading to ply issues and paint only the hulls.

My boat will spend a fair bit of time in the water moored or sitting on a cradle out in the weather during summer so I think full coating is the go. I have precoated the sheets so I only need to seal the plank edges as sanding pox on eleven planks after the event did not really appeal.
As for other bits again I think the encapsulation rules will apply. The other builds I've looked at have used the pox sparingly (hard to get at places etc.) and seem to only use varnish on thwarts, spars and things.

The other aspect is fastenings instead of glue and apart from the skeg were a couple of bronze bolts are called up that make sense to me for a bit of impact support, the stern knee and brass rub strip no other permanent screws are needed IMHO. I suspect glue is used as well as fastenings on the other builds in things like the bedlogs and keel however it is a bit hard to tell and I'm new to all this.

I will be using silicon bronze screws as stipulated as well as epoxy though in all the joints but only temporary screws in the planks.

I agree less pox the better however at the end of the day the evidence is clear it is worth the discomfort and extra work for durability.

I think you've gone a long way to using less epoxy already.
Pre-coating everything is a great idea.
And judging from the pictures of those joints, you won't be needing to use epoxy to fill any unnecessary gaps.

Keep up the good work.

Cheers


mickj

Transom has been plugged scraped and epoxied both sides after fitting the knee of course. Hog beveled glued to stem and screwed to the molds so we are ready to plank.

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