Epoxy and Cyanoacrylate (SuperGlue) on Plywood Boats

And you paid $150 ? - heres 7 kayaks for $100
http://www.gumtree.com.au/s-ad/blac...fibreglass-sit-in-kayaks-and-canoe/1042939527

Yeah, if i could find decently sized boats for $150, I would too. Even the top of the range plastic kayaks have a really low and constricted cockpit design.

When I bought the design (attached), I got one that would fit my - ahem, 'substantial physique'. Even so, the leg room and cockpit entry is like slipping into a suit of armour. For these tiny little glass or plastic jobs, it would be even worse.

When I started these things, I was thinking of my much younger, more flexible youth -


My hero is this guy

 

Back on topic.
IMHO there is no place for CA glues on any marine structures, for the simple reason that CA glues are not waterproof.
Epoxy rules,---- although not all epoxies are waterproof.
If you are building a wooden boat you should be careful to use a proven boatbuilding epoxy which has 100% solids thinners.

 

Watson,

Where did you get the information that superglue will be destroyed by moisture? I asked at work, and my materials guy said there is no way water will affect superglue.

Have you seen Nick Shades use of superglue for wooden kayaks? He only uses it for "spot welding" points together, not making the full joint. He also uses a "medium" viscosity CA glue - not the typical which just penetrates in to the grain and glues nothing. http://www.guillemot-kayaks.com/guillemot/blog/nick/repairing_damaged_strip shows repair of a strip, there are othere videos where he shows using the same glue to hole down a strip every 4" or so. His boats are pretty high dollar when he makes them. I don't think he would use CA if he thought it would come apart.

If you coat the CA with epoxy it probably will protect it just as well as it does wood.

 

I was going to address this too, but the thread moved, so I didn't bother. Cyanoacrylate is waterproof, though not all are. These CA adhesives are popular with aquarium makers and coral decorators & restorers, though care must be taken the additional compounds are included to make them waterproof (phthalic anhydride usually).

Viscosity is typically handled with silica and cure rates use oils (linseed is common). They do get some penetration, though considering it's cost, epoxy is more economical, not to mention has much better working times.

 

Hotmelt is a flexible option

I came across the below review by a BoatBuilder in Bridport.

An option we hadn't considered:

http://www.techsil.co.uk/press/GasTec600_Review/

 

Kate, welcome to BoatDesign.net. That gas-heated hot-melt glue gun is a great idea.

 

Adding dust to superglue makes it stronger and sets harder. Flour, corn starch, chalk dust, about any kind of dust. But the epoxy sounds better.

 

Staple removal?

Why take the time to remove the metal staple? Have you ever heard of RAPTOR composite fasteners? I started using them recently and I love them! They have incredible holding power and I do not have to remove them. They can be sawed and sanded without damaging tooling. You should check them out. I think their website is: www.raptornails.com - watch the wooden boat building video.

 

Yeah - but the price of the gun was the killer for me.

 

The gun is pretty pricey. However, they let me try the gun without purchasing it for 15 days to test how it would work in my application. Once I used it in my shop I knew I had to bite the bullet and spend the money on the gun. Trust me... it's worth it once you consider the time and money it can save you in the long run!

 

getting back to the original topic then -

At the stem I just glue a simple wood wedge on the stem edge of the plank, plane it to fit and glue it to the other plank - instant stem. For a bluff bow I'll put a wedge on each plank. The glue joint is a good fit so I can use Titebond III instead of epoxy to save time. To keep the planks firmly aligned I drill through the stem for a couple of BBQ sticks and tie the planks together with a simple figure of eight, then cut off the sticks with a flush-cut saw.

I've also replaced epoxy fillets from the chines by using chine logs; these are glued with Titebond III to the flat planks (sheer and bottom for a five planker) and planed to accept the bilge planks which are epoxied, as it's hard to get the perfect joint that Titebond III demands. Titebond III is OK for boats that are dry-docked, but I wouldn't trust it below the waterline if the boat is going to soak.

This method particularly suits narrow boats like canoes and is neater, cheaper, faster and lighter than poured stems and fillets IMHO.

 

superglue and bicarbonate of soda mixed, turn into a rock as hard as a chunk of glass

When I was younger and had younger friends, we carried superglue on boar hunts.
when a dog got disemboweled, stuff his guts back in,pick the leaves and twigs out, superglue the wound edges together, and frequently, the dog would run off and rejoin the hunt. Not kidding.

 

They do have a cheaper gun which I have been looking at, from what I can work out it works the same, but has a much lower output and is more for hobby type requirement rather than heavy use.

http://www.techsil.co.uk/tec-175-hm-hobby-glue-gun.html

 

I note several posts suggesting Titebond III. This material is a polyvinyl acetate based product, subject to creep under stress and is not a gap-filling adhesive. It is not recommended for structural bonding. See the Titebond website for more information. I don't think it's a good choice for s&g construction at all. At least not if you want your boat to last a while. And if you're selling boats, it might be prudent to check with your product liability insurance underwriter. (You do have product liability insurance, right?)