[Public-List] Hull stiffeners and Yves Gelinas

[Don Lang]

Sounds like I'm on the right track so far.
I have installed the first bulkhead in my boat; The forward chain locker bulkhead.
I made it watertight from the cabin and put a platform in the bottom above the water line 
so it can be made self draining and an access hatch on deck
(well, the hole for one so far:)).

Here is a link for the stiffeners I am considering:
 http://www.tacomarine.com/cat--Hull-Stiffeners--cat_hull_stiffener.html

In my hull there is a wide bands of glass running fore and aft where I presume the liner and shelves were glassed in.
You can see them in the second picture down on my last blog entry:  http://alberg30.blogspot.com/
The lower ones run all the way aft to where the companionway bulkhead would be.
I was thinking of adding the stiffeners along those lines and bonding the bunks to the top of the stiffeners 
(keeping the bunks at least a half inch away from the hull) thereby avoiding hard spots in the bunk-hull-joint area.
As C.B. Currier mentioned in his post, my hull also flexes considerably in the area of the jack stands.
That was one of the reasons I was thinking stiffeners might be a good idea, the other was to have a strong but flexible joint
 for the bunks to sit on, and to re-enforce the hull when pounding to windward or heaving to in a gale (my preferred heavy-weather tactic).

The bulkheads between the cockpit and the salon when installed will be made watertight also.
I think we'll go with Goit toe rail in the spring and glass the hull-deck joint on the outside before bolting it down. 
We've prepped the hull-deck joint for tabbing every two feet or so inside the boat also.
Anyplace that we have wood adjoining the hull (bulkheads, platforms, etc)we have placed a 1/2 inch layer of foam between the wood and the hull
to keep them off of the hull and then glassed them in place with a radius fillet or a foam radius using west system epoxy and biaxial glass tabbing.

I noticed some bondo-like putty applied to the aft side of the beam that supports the mast.
When I ground it out I got down to the aluminum plate in places. 
The glass in the area was not thoroughly wet out when applied and there is a number of trapped air pockets within the glass as well.
I was going to repair this with layers of 3.5 oz biaxial glass.
Do beams with aluminum in them require further strengthening?
Do you think the area would benefit from a layer of Kevlar or carbon fiber perhaps?
 
Thanks again to all for the input!

Cheers,  Don #473



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Hi,

I've read Yves' book (in French) about his solo circumnavigation. 
He has an appendix about the upgrades he made to his Alberg 30.
  He did make watertight compartments out of the chain locker and 
the aft lazerette. He also had provisions for a further 
watertight door to be installed in an emergency at the main 
bulkhead under the mast. I think he also made the division 
between the saloon and the cookpit/lockers watertight as well. 
Easy for him, since he got rid of the engine. I didn't think he 
added hull stiffeners, but now I've just read his web site and 
talks about reinforcing the hull.

The biggest modification was replacing the mast. The new mast had 
a thicker section and double spreaders. He also replaced the 
rigging with a (slightly) larger gauge. He was, of course 
dismasted in the Southern Ocean. In the book, he attributes the 
failure to (initially) a weakening of the cross-beam under the 
mast during a capsize. The mast step dropped slightly. This led 
to the rigging being slightly loose, which increased shock loads 
on the rigging. The ultimate failure which lead to the dismasting 
was the failure of one of the chainplate bolts. He hadn't changed 
the original 1/4" bolts for the lower shrouds chainplates. 
Upgrading these bolts to 5/15" is the only structural upgrade 
I've made to my boat.


Stephen
#495 Quasar













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