Interior Framing

[SkiprJohn]

My experience with Philippine Mahogany is that it rots quickly in freshwater. I wouldn't use either the timber or the ply for boatbuilding.
Regards,
JohnL

[Steve Rust]

Western Red Cedar is used quite a bit for cold molding and is readily available. Similar woods would be White Cedar and Juniper. Black Locust is great for frames and exterior trim also commonly used for wooden cleats. Spruce has little rot resistance but due to it's light weight is/was used for masts. Much of the mahagony on the market today is not true mahagony so the real stuff gets a bad rap. The real stuff is a great boatbuilding wood used for planking, cabin sides, and exterior trim. It comes from Central America. African "mahogany" may be okay but Philippine is crap. The domestic plywood(fir) is so poor here that you would need to find a source for marine grade fir or imported plywood like okume, merenti, mahagony,etc. Long leaf yellow pine salvaged from old buildings is excellant. I built a deck for my house 20 years ago with this and a scrub and clear sealer applied every few years make it look as good as the day I built it. Oak is used for frames, deadwood, keels and other structural members due to it's great strenght but I would not use it for exterior trim. There is white and red oak and I think white is prefered.
Wooden boats rot from fresh water leaking in from rain or whatever. Saltwater acts more like a preservative.

[glenn.225]

Thanks Steve

I have been surfing around a bit and if I ever do build and choose wood over steel, it would probably a something like Dudley Dix’sDidi 34. (A bit larger than 30 but it would have everything and space to spare)
I think I would use BlackLocust for frames and okume plywood, but top it off with a couple of layers of fabric and epoxy for extra strength.
If you started with the interior lay out and then frames and finally the sheeting, plywood will hold the shape to cover with fabric, making fairing easy.

Glenn

[delmarrey]

Originally Posted by glenn.225

BTW, how do you quote two people?

Glenn

Before replying, see that little quote icon in the lower right hand corner. Click that and edit out what you don't want.

Or, while in the Reply window, at the top of the reply box click on the quote icon (looks like a page with words in it), Copy and paste what you want in it. If it's a Members quote you can add "=members name" between the word QUOTE and the ]. e.g. ( [QUOTE=name] ). That will ID the member that made the statement.

Originally Posted by glenn.225

I think I would use BlackLocust for frames and okume plywood, but top it off with a couple of layers of fabric and epoxy for extra strength.
If you started with the interior lay out and then frames and finally the sheeting, plywood will hold the shape to cover with fabric, making fairing easy.

Glassing over ply is not good practice. It's commonly known that the wood retains moisture and rots.

[glenn.225]

Originally Posted by delmarrey

Glassing over ply is not good practice. It's commonly known that the wood retains moisture and rots.

delmarrey thanks for the help.

I understand some of the issues about glass over wood, but if done in same fashion as cold molding it would be completely sealed, and they for the most part don't have problems. The ply could be thin layers and used to retain shape without creating a mold. This would allow larger sections thus quicker construction.

note: Home and Article - Radius chine plywood boat building

Glenn

[delmarrey]

Originally Posted by DUDLEY DIX

An alternative method of finishing would be to cover the hull with a layer of glass cloth but I emphasise that it must be set in epoxy, not polyester resin for effective protection. This method will require some fairing afterwards to produce a smooth hull but will add surface hardness to resist damage from impact with debris, marinas etc.

Even with epoxy water can get on the inside. The wood should be sealed on both surfaces to be safe, like on regular GRP boats. And if it's rain water (fresh), rot is inevitable.

And with such a thin layer of glass I'd be worried about delamination as the hull twisted, being mostly wood.

Please refer to this thread...... http://www.cruisersforum.com/forums/...ces-12413.html

Don't mean to burst your bubble. Not everything you read on the net is correct. There are multiple threads on here discouraging glass over wood.

This vessel was bought and abandoned three times before it was finally crushed/scrapped.

[glenn.225]

Nice Post.

And as I have said still just kicking around the idea. Lots of time for research and sober second thought. But one of these days I may get the ambition to try.

Glenn