If it's any help to you, I did this on my T38. From working on a Rescue boat years ago, I remember only to well that most yachts had no lashing points on deck strong enough to withstand a tow in bad weather. I used solid timber all the way down to the keel. I was aiming to be able to pick the boat up by the stem or stern posts. Overkill? Maybe but I don't think it detracts in any way. But hopefully I'll never have to test it....
For a given thickness the strength of plywood is hard to beat.
I would hesitate to bury naturally grown wood in thick beds of epoxy (which you do at stem and stern) Rot can start from inside the timber, we just had a case with a tiller bar on one of our club boats. This does not happen with plywood becuse it is 'dead'.
Generally I find it unneccessary to make any changes to the design in order to improve on the strength of the boat.
Well built anchor/towing cleats on the cabin roof will be plenty strong.
Does rosewood "move" more than teak? Likely. The Gougeon Bros., makers of West System Epoxies, don't recommend encapsulation of solid wood sections greater than 1" square, if memory serves. Last spring, I used 3/4" Joubert Occume ply to build new rudders for my boat; I would bet that a lamination of of BS1088 Joubert would be an even better solution. Expensive stuff, but if just used for the important bits, like stems, quite tolerable.
I'll be using new guinea rosewood or northern kauri pine which is a bit different from the northern hemisphere stuff and very stable. Teak is probably to oily for epoxy.
Gougeons' book is a great primer and very relevant but now 30 years old!
Will more than likely just end up facing all the exposed edges with timber as good ply is very strong. especially with the stern posts.
BS1088 is only good if it comes out of Britain, joubert being the exception and AS is far stronger.. most of the BS stuff here is from asia and its crap.....
Will be using Australian standard in hoop pine for my construction. plantation grown, quality assured and sustainable forestry. bit more expensive, but hey thats my bent.
Have no intention from deviating from the original plans. Other than an aluminum mast and some king posts perhaps.
edit: West System has a relatively new epoxy out called G-Flex: absorbs more shock loads than the normal stuff, and works on oily stuff too. Longer open time as well. Not meant for wetting out fiberglass.
Lee i have been doing a bit of research on pywood available in oz and have also decided to go with hoop pine as the quality does knock the other crap on offer for six.what epoxy brand will you be using?
Gougeons Book was revised, reorganized and updated in 2005. It is it's 5th edition. The information inside is really helpful, IMO Joubert plywood is also really nice stuff to work with. I have built spars for tall ships by laminating lifts of 1 1/2" douglas fir into large enough pieces. they are all still holding up. David
My bad with the guogeon bros, Boatsmith, I have there first edition purchased in the 80's and had'nt even bothered to check....
Australia has one distributor of Joubert ply and is in Tasmania a little island of the bottom of oz about 4000 klm away
so will end up costing about $150 aus a sheet of 6mm as opposed to hoop being about $100.
Am going aluminium for the mast as its quicker, cheaper and readily available.
Paul will be using FGI R180 epoxy with slow hardener can get it for $17.50 litre/Kg.