Debating Stringer Construction

The ol' time boatbuilders say just use glass over high quality plywood and build it right. You'll never have a problem if glassed correctly.

Young punks like myself often shy away from wood. A large U-shaped stringer, carbon fiber reinforced and filled with closed-cell foam sounds pretty good to me. In a 46' sportfish with a 17.5' beam, the cross stringers are very important as well as a few elbows.

How would you do it?

http://www.boatdesign.net/gallery/showphoto.php/photo/9315/limit/recent

 

I don't think it is necessary by any means to have carbon fibre in stringers. But someone will correct me if I'm wrong.

 

Having spent many weeks picking out rotten one-time solid hardwood from encapsulated stringers, I'd say "never EVER use wood". Plywood would be even worse. All it takes is a small pin-hole to allow moisture in, which can never get out - and you've got BIG trouble a few years down the line. Stringers invite people to bolt deck fittings to 'em, and if the fittings or sealant works loose ....

For short stringers supporting a deck (say) or similar, I'd be inclined to lay down some old rot-proof trawl rope, simply as a means of filling the space, then glass over that. The rope won't add much strength of course (unless you soak it in epoxy first), so ignore it when deciding how much roving to lay down to form the stringer.

Colin

 

"The ol time boatbuilders" wouldn't think of using glass or epoxy. Try oak cedar and caulk

 

Most folks build the stringers to be strong enough by their shape alone , the core, foam , cardboard , ply is ONLY to get the stringer built.

Engine beds are different tho.

FF