Eureka Canoe

[Boatmik]

Warms the cockles of me heart!

Well done Col!

MIK

[woodeneye]

I wasn't sure where this should go. It's an original 1891 print of Baden Powell's that is for sale here.

[Boatmik]

His original JPEG?

It is hard to work out where it should go. I guess it is just fine here.

[Mezix]

Hello Boatbuilders,
Enthusiastic Hungarian boat-builders are bombarding me with questions about how to make the Eureka lighter. We discussed the option of not building the air-tank/transom/deck, but they seem to want more ... or less concerning the weight.
The next idea is balsa. My knowledge has run out at this point. What do you think? Can they build spacer blocks or the deck support using balsa? What are your experiences with this material?
Thanks
Best
Csaba

[keyhavenpotter]

Csaba, have you been through this article on MIK's site about building a lightweight Eureka?

Eureka Lightweight Plywood Canoes - more pictures and review - Michael Storer Boat Design

Or are you wanting it lighter still?

Brian

[Boatmik]

Howdy Csaba,

You need plywood - so making the boat lighter is difficult as the current lightest plywood is the Gaboon. The European made Gaboons are usually gaboon right through.

There is no balsa plywood.

The canoe already is reasonably light and the article pointed out by Brian is a good guide.

To do very light boats takes a consistent process where every decision about what to use and how to use it is thought about carefully. Just changing the plywood is not enough if the person is lazy about the timber selection for the other parts, the seat design, the glass weight chosen. How much epoxy is applied.

You can get down to 15kg with some effort to keep every aspect light in the build. The lightest available timber used to be Western Red Cedar, but now it is Paulownia from China which is slowly becoming available around the world. So either of these will help if chosen for the solid timber. You could use a combination of balsa for the gunwales with a thin strip of a stronger but light timber on the outside. The seats could be done of balsa with glass on the top and bottom faces. Any balsa would need to be epoxy sealed with three coats very carefully or it will soak up more water than the weight saved.

The gunwale and inwale size can be reduced.

Balsa is unsuitable for the inwales and the spacer blocks as these parts are already very small.

The knees in the end can be plywood.

Glass tape can be cut out of 2oz (70gsm) cloth.

If going down to 4mm plywood you need to use more frequent stitching and I would recommend glassing the bottom panel on the outside and overlapping 25mm onto the bilge panel.

Hope this helps
MIK

[nickpullen]

Build your seats like this... Then lace them up. Much more comfortable. and lighter. I used Paulownia 45x15 for the frames and 45mm wide 4mm ply for the surround...

[Mezix]

Thank you guys. I will digest your answers and the article, then transmit them to the Hungarians. I will make a research on Paulownia as well.
Happy boatbuilding.
Cheers from the snowy Budapest
Csaba

[Boatmik]

Craig dropped me a line

Hi Michael,

Please find a link to some photos of my Eureka, took me over a year but I got there in the end.

Dec 2009 055.jpg - Windows Live

And in the water,

Dec 2009 068.jpg - Windows Live

I found your PDF package for the canoe informative and more than sufficient for me to build my first canoe.

I need to build some seats but just had to get it in the water for my Christmas vacation just past.

Thanks for providing me and others with an enjoyable project.

Craig.

[AlexN]

Well, I think that, after seeing all the lovely Eurekas on this and other threads, I might switch the build-order of the canoe and the Goat and do the canoe first (after I've finished the 'Duck, thrown out all the rubbish in and around the workshop, rebuilt/finished the work area, redesigned the workshop, re-populated the workshop, etc., etc. etc.: in other words probably not before Christmas - next year ;).

All these boats have set a standard that is going to be pretty hard for me to get even close to, but I am determined to build this one light (unlike my 10-ton 'Duck). And I'm going to nick a lot of the ideas that I've seen on this thread and others, too ;). So thanks in advance, everyone!

And some canoeing might make me a bit fitter, so that I stay healthier longer :).

Cheers,
AlexN.

[Boatmik]

(and can drive the duck harder)

MIK

[AlexN]

Yep :). Not to mention the Goat!

Actually, I've just finished watching your Bob Bauze's Eureka Flickr set(not reading the "Sailmaker's Apprentice" as I had intended ;), There are some very useful tips in that one.

Still not worked out whether to glass or fillet the internal joins yet - I'd actually like to glass the joins after removing the stitches - if that can be done. I think BM and Nick did that, didn't they? Spot-glued the outside of the joints, then snipped and pulled the wire (carefully). Or did they fillet the joints after that? But think of the weight saving without all that heavy metal ;).

And definitely "4 mm" ply (the dimension is in quotes since the "4 mm" I used on the 'Duck was actually 3.6 mm - that's 10 % thinner!). Bob's gaboon looks lovely :). Well, all the gaboon that I've seen looks nice!

I'd thought to make the gunwales meet at the centreline at bow and stern, then discounted that idea because of a potentially vulnerable joint: but I notice that Bob had done that, and on further reflection the joint, i.e., the glue, isn't going to be weak at all. So I'm back to "Plan A" on that one. The "lightweight canoe's" non-slide, non-slip seats are going in, too. I thought that green plastic coated washing line would look really nice there <ducks ;>.

Cheers,
Alex.

[Boatmik]

You might have to check their threads for how they did it. I can't remember now.

I think the midge might have been the first to use fillets on the inside - even before I worked out that it was better to glass tape the upper join inside hte buoyancy tank only. That saves a lot of hassle.

The duckflat school starts in the next week or so - they will have a Eureka and a Goat. A small class this time with three or four other boats.

MIK

MIK

[AlexN]

OK, thanks. Looks as though Nick filleted the internal joins - without removing the "staples", as far as I can tell. I know I've seen it recently - someone used plastic-coated electrical wire, thought it was Midge but wasn't - wasn't Nick either.

Have to back-track a bit. Thanks for DFABBS info :). Or is it ADFBBS, or DFBBSA, or...

Cheers,
Alex.

[AlexN]

Ah ha! It was b.o.a.t., alias AJ! I knew I'd seen it somewhere!

Post 465, page 31

Robert, I use 0.9mm insulated telephone jumper (hook-up) wire on 4mm ply.
I leave the insulation on & after tack-gluing my edges, pull out the wires & glue & tape
the joints properly. It's quite a bit more work to do this, but it suits the peculiar order
of my mind to do so.

Are you building in 4mm or 6mm ? 6mm would probably need thicker wire at the turn
of the stems.

cheers
Alan J

Now, when AJ says "pull out the wires & glue & tape", did he mean that he glued the outside and taped it, and taped and resined the inside; or, did he mean that he glued and taped the outside and filleted the internal joint? I dare say I'd better PM him about it... My original solution to reduce the risk of the boat ends from springing was to use packaging and or duct tape, in order to avoid having to fill yet more holes (not my favourite occupation!).

There was an attached picture which didn't come over with the quote - here it is: