Marine glue for wood boat

Picked up a quart of 105 West System....let you know how it works for my application...

 

The boat is started...

 

New pics of progress

 

boat progress

 

New pics!

 

So, how much does it weigh ?

 

It weighs less than 300 at this time...

 

The 3M 5200 is a rubbery, polyurethane sealant and has a adhesive properties but sometime it can be used as a glue. Under water saturation it fails as a glue without high clamping pressure. it's not used as stand-alone marine glue.

 

Yes, 3M-5200 is used as a stand alone adhesive (it's not a glue) and it's elasticity isn't as flexible as most of the other adhesive/sealants available (it's surprisingly stiff). I agree it needs to be well clamped on wooden or porous substrates, as it will release if not (underwater applications). I've seen plenty of lapstrakes ruined with this stuff for this reason.

In this application, a traditional dory lap build, 3M-5200 will work, because the frames will do most of the work, while the goo just acts as an aggressive sealant. It has more than enough elongation (about 300%) to work in this role, though repairs will be a bugger.

 

I am using west 305 for my screw plugs(mixed with saw dust) ...is there something better? Anything like a putty?

 

Well I'm not sure about your "West 305", but West System 405 is a filleting blend, which is a combination of silica, balloons, some talc and a touch of wood flour, ideal for filling screw holes and other fairing duties.

 

OK,so will the 305 mixed with saw dust accomplish the same?....are do I need to get the 405?

 

The West site will tell you what these products do, though I don't know of a 305 filler material.

Adding wood flour to 405 will make the fairing compound much tougher to sand, so yeah, you can fill screw holes with it, but it'll be harder to fair out afterward. Unless you have a load bearing situation around these filled screw holes, I don't see the need for anything else in the mix, except silica to control situation dependent viscosity requirements, such as vertical surfaces.

 

I.m thinking about saturation of the cypress lapstrake,to counter rot...whats your take?

 

Cypress is a thirsty species and I'll bet it'll suck up a huge amount of weight in goo. Since you can't behind and under the frames and other areas now assembled, encapsulation isn't fully possible, so I'd think against it. Depending on the sub species, most cypress is fair rot resistant naturally and as a trailer boat, she can be permitted to dry out, so not as much a concern. My big concern with cypress planking like yours is, it looks to be flat sawn and pretty wide planks. With cypress, this means a lot of movement, testing each fastener and glue line, making a good argument for some sort of sealer.

The planking will only rot if standing water is permitted to stay in the boat, so if you take care of her, keep her paint in good shape, you shouldn't have worries. Use a good epoxy based primer and keep her clean and dry.