Eureka Canoe

[Boatmik]

What a great score Kev,

That happened when we built the two quick canoes in France last year. We found they only had the big sheets.

I sat down on the spot with my computer (it's almost always in my backpack), pulled up the drawings and checked they would fit on two big sheets only.

There is only one caution ... if moving the join in the panels of the canoe from the midpoint you will have to mark the midpoint carefully when you draw the boat up so that you can line everything up.

Also the bilge panel is highly twisted in the ends so you want to keep the join for that panel near the middle.

Best wishes (and congrats!)

Michael

[Flatdog]

Thanks for the warning .

I am going to mark out the original sheet size ( 2440x1220 ) from where the two join and then mark out everything as on the plan. I don't think the marking and cutting out stage is a good place for creativity and innovation .

This could be a couple of weeks down the track. It's -8c outside at 11 o-clock in the morning and in our garage it's not much above that.

(I'm exited anyway .) I think I meant excited.

Kev.

[Flatdog]

I'm about to order my epoxy and glass mat. Well, as soon as the temperatures get above freezing ( -15c last night ) and I don't have to worry about the delivery company leaving my apoxy in a freezing van over night . The company I,m ordering from specialize in epoxy for boats, aircraft and wind turbines Glasfilamentgewebe . I'm stuck between ordering 80gsm (2.8oz) or 163gsm (5.8oz). I know Mik says to use 2oz in the plans but here I am wringing my hands together wondering if it will be strong enough. Can anyone let me know what they used on theirs.

Thanks.

Kev.

[Boatmik]

Howdy,

Lighter still would be perfectly fine. Promise.

This boat is 4mm ply with 2oz glass over the top. This shows that canoes and kayaks built with 4oz or 6oz glass are rather overbuilt.



You can always hit something hard enough to break it But if the Jarcat in the picture is OK and there are a few hundred built, the little Eureka canoe will be fine indeed.

There has been an "arms race" to build boats stronger and stronger but it has become crazy when some are saying that the inside and outside of light simple boats like canoes and kayaks have to be glassed ... and the weights keep going up too. In the "good old days" we used to glass tape the seams only ... no glass and the boats were fine in 3mm and 4mm ply.

Also you don't need to glass the whole thing on the outside. Bottom, bilge panels then one inch onto the topside ply.

Best wishes
MIK

[Flatdog]

Thanks Mik. 80gsm it is. I think I must be suffering from TMIS (Too Much Information Syndrome) I should stop reading about building canoes and get on with ours . That is when it gets warmer.

Thats a really nice cat.

Kev.

[Boatmik]

Howdy Kev,

Yes ... the Jarcat is quite famous in OZ. It is one of the few little cats to really embrace the idea of keeping the weight down but making the whole thing beautifully light and simple

Ross Turner the designer was quite innovative. While the upwind performance might not be quite up to modern cat standards it is not a slouch. And it is hard to compete with 10 to 15 knots dead upwind under different sized outboards!

Michael

[Flatdog]

While we're living in the cold down here in middle Europa ( up for the Aussies ) I've had a chance to scrutinize (good word) the canoe plans. With pre coating the panels, is it the same when you are going to glass the outside? Three coats? It seems to be a lot of added weight if I give three coats of epoxy plus glass on top. Have I answered my own question here or is it a structural thing?

Thanks.

Kev.

Have I got too much time to "scrutinize"

[Boatmik]

Howdy ... there is a LOT of labour to be saved if the inside of the boat is precoated and sanded. Not to mention the much easier clean up of every stage after assembly.

I wouldn't do the outside of the hull for the reasons you specify. It is a waste of epoxy and a bit of a waste of labour because the outside is so easy to do later. Especially with the 2oz (70GSM) glass.

Best wishes
Michael

[Cabra Loca]

Hi all,
after finished a GIS last year (very, very happy...), I just started to build another Mik's plan: an Eureka canoe with outriggers and a sail. Just for your info, here-whit a Blog (In Spanish but with pictures) about all the building process. Cheers
The Blog: Canoe Eureka - Daiquiiiri

[Shas Cho]

Michael,
In your article 'The Boat That (almost) Made Us Our Fortunes'
you mention developing small models of the Eureka
for Japanese kids to build.
I'm neither Japanese nor a kid,
but I'd love to build a model Eureka
to fondle and admire until I can build the full-sized canoe.
Heck, I'll even give you twenty five cents! :=)

Seriously, it's a shame to see your effort go to waste.
How about it-
are you interested in selling those plans?

- Shas

[Shas Cho]

Speaking of the inside of the boat...

Michael,

I'm a big fan of your Eureka canoe
If I am able to build future boats
I'm pretty sure my next one will be the Eureka.
The one detail that I find quite off-putting
is the butt-joint block running from gun'l to gun'l.
To me it downgrades the appearance
from "hand-crafted wooden vessel"
to "home-made plywood boat."
I believe it can be safely and properly eliminated,
and I'd like your opinion.

I've built boats with my kids for the past 20 years,
ranging from Phil Bolger's 5'6" Tortoise
to a 27' blue water cruiser with a 5,000 pound keel.
Our first six boats were made with Bolger stitch-and-glue plans
and 'Dynamite' Payson's excellent books.
Payson sent out a flyer
that changed the way we make butt blocks.

He simply butted the sheets or panels
and spanned the butt with six inches (as I recall)
of fibreglass and polyester resin.
After it cured he (carefully!) flipped the assembly
and glassed the other side in the same way.
He did a number of experiments with this method
and became quite confident in recommending it.

After the first time I used this technique
I eliminated a source of potential catastrophe
as well as a substantial waiting period
by glassing both sides of the butt simultaneously;
After doing a dry run to make sure everything lined up
I lay down a substantial sheet of waxed paper.
Then I lay down a six-inch strip of glass cloth,
leaving it a couple of inches longer than necessary
and saturate it with resin (I now use epoxy).
I prime the relevant portion of the sheets
and carefully lay the butted ends on top of the wet glass.
At this point I lay weights on the panels
well away from the joint to prevent any movement.
Then prime the upward-facing joint
and cover it with another strip of glass and wet it out
before laying more waxed paper over the assembly.
I lay plywood over the joint and add weights as clamps.
When it has cured the joint is smooth and strong.
A bit of sanding feathers the edges of the glass,
leaving a virtually invisible joint
whether it's to be painted or left 'bright.'

We used this tip on Bolger's 11' Pirogue and 12' Cartopper
and after more than 20 years of use and abuse
have found no flexing or cracking or delamination.
And that's with polyester resin!

Even though your plans do not call for the butts to be staggered
they are each adjacent to a longitudinal angle,
which provides substantial support.
I'm neither a designer nor an engineer,
but I don't see why disappearing butt joints
wouldn't work well on the Eureka.
I'm very interested in your thoughts on this technique.

- Shas

[tatolazo]

Hi Guys.
It seems I will be forced to use 6mm ply because 4 and 5 mm are now out of market. and 6 mm is going out of stock forever as well in my area. The main thing is I have being thinking about using copper wire or plastic ties to stitch the plywood sheets together. Wich material is best suited for the job??

in case plastic ties can be used as well eith the same final quality, wich size should be correct for a 6 mm plywood use, i was thinking about 4 to 5 mm wide to put enought strengh pulling itl without elongation of the tie wich coul mean poor fitting of the plywood parts.

Hope you can help weith your experience and inputs.

Thanks in advance.

Tato Lazo
Chile.

[Flatdog]

Hi Tatolazo.

I'm a bit busy at the moment but I'll get back to you as soon as I can and hopefully I can help.

Kev (Flatdog)

[colburge]

Hi Guys.
It seems I will be forced to use 6mm ply because 4 and 5 mm are now out of market. and 6 mm is going out of stock forever as well in my area. The main thing is I have being thinking about using copper wire or plastic ties to stitch the plywood sheets together. Wich material is best suited for the job??

in case plastic ties can be used as well eith the same final quality, wich size should be correct for a 6 mm plywood use, i was thinking about 4 to 5 mm wide to put enought strengh pulling itl without elongation of the tie wich coul mean poor fitting of the plywood parts.

Hope you can help weith your experience and inputs.

Thanks in advance.

Tato Lazo
Chile.

Hi

I used thin stuff (1.5mm maybe) on my 4mm and I broke a few of them, so I would go bigger on yours, maybe 3mm diameter. 5mm would be too big and hard to twist.

Col

[Flatdog]

Hi Tatolazo,

I used 5mm ply and used 2.5mm copper wire that I stripped down from 3 core eletric cable and drilled a 3mm hole with a new wood bit. Just the every day cable you find in houses. I had a pile of old cable. It worked fine and I didn't break any ties. I tied the panels together very loosely for a start and when I had it all together, starting from the butt strps worked my way to the stems or ends and tightened the ties up a bit at a time. I probably did this three or four times until the panels were together. If you watch the wires with the first couple you can see where they start to pull into the side of the holes and you can move the panels to fit as you go. I found that I didn't need them to be really tight, just firm.

Just a thought. When you drill the holes make sure you have a piece of scrap wood on the other side of the panel to stop the ply breaking out around the hole when the drill comes through.

See how you go. Have fun.

Cheers Kev.