Thread: Lightest Ply

HI BOBBO,

I could not imagine a lighter or stiffer canoe built from clinker, glue lapped ply.

I have not seen the balsa canoe you speak of, but in my experience, as soon as you start composites the weight increases. I may be wrong here as I repeat I have not seen the specs.

I would stick with glued lap clinker. Just my opinion.

Paul.

BoatBuilder for 37 years.

Howdy,

Can anyone help me to go lighter?

What about a skin-on-frame canoe?

Many moons i built a Mosquito catamaran to race and Gaboon was the best i could come up with for weight.

You could try a balsa one and then give it a coat with thined PU resin to waterproof/strengthen it but youd have to watch the weight.
Another option would be balsa and then iron on laminating film.
Have alook here http://pldaniels.com/flying/balsa/la...aft-tails.html for some info on it.

Gaboon is the best way as far as plywood goes. Until someone starts making a paulownia plywood!

Composites can be lighter for some purposes but you cannot use much glass at all.

Lightweight boatbuilding is more about a consistent approach than anything .. and wood is the lightest of the boatbuilding materials apart from foams.

This is why you have to be very careful with glass ... which is 8 or more times the weight of wood and epoxy.

The polyurethane has very little tensile strength and may not bond adequately to the timber. It would also fail to prevent the timber from splitting along the grain. This can be ribs, plywood (as it has crossways veneers), cold moulding (same) or using glass on the inside and outside of a strip boat. Preventing timber from splitting encompasses most of the history of boat building and design.

The link the balsa canoe is here

Most skin on frame boats will be heavier (The geodesic ultralights used to claim to be the lightest type of construction ... but their wee lassie at 18lbs was a bit more than my balsa one 12lbs) and have the problem that the hull skin distorts reducing efficiency.

The question of course is whether the balsa boat is a true practical boat ... I think it is with some caveats.

Originally Posted by bobbo

In the pursuit of ever lighter canoes I have come to believe that Gaboon ply at around 7.5 kg for a 2440x1220x.004 sheet is about the best I can expect.
Does other forum members experience aggree with this?
Can anyone help me to go lighter?
I'm intrigued by Michael Storer's Balsa canoe but I dislike working with 'glass, and prefer the clinker ply method.

I can provide paulownia plywood, the weight is only about 3.7kg per 2440X1220X4mm sizes sheet.
But I am not sure if it is strong enough. If you like, I can send your some samples to test.

Best Regards
Danny

Does gaboon need to be pretreated against rot or is it naturally resistant like cedar or hardwood ?

If not what did you use to pre treat it ?