sister framing comment bad repair technique?

[sdowney717]

http://www.macnaughtongroup.com/concordia_yawl.htm
I have always thought the same as well.
Also does sister framing reduce the potential value of the boat?

[George Roberts]

It is true that sharp bends in wood weaken the wood. It is poor construction to simply bend wood to suit the drawings. This goes for new construction or repairs.

So how does one get sharp curves? You bend to a reasonable curve and fill to the desired profile with blocking.

I can not afford a Concordia so I don't know if sistering is a price consideration. But if I had a Concordia that had frames in need of repair, I would repair them as I wrote above.

[Thad]

Sorry not to have read the whole link, but.... Like many other A&R productions the Concordia yawls had problems when first launched with broken frames/ribs. The breaks typically occured at the tight turns but were caused by the (too) tight planking working on the most stressed parts of the ribs. The Concordia Co. that was selling the boats went through a sistering program from the start.
It is true that it is better to replace broken ribs, but when this entails removing removing a whole interior, for example, and there has been no loss of shape, it may well be reasonable to sister. I'm not particularly congratulating myself, but I did just that on a Frisco Flyer a couple of days ago. Sisters were recommended by Paul Haley. Why? because it is a copper riveted vessel still having it's shape and the sisters will carry strength across the break. Certainly the boat is better off with the sisters than without (I say "certainly" but I know that there are good jobs and bad jobs, and cases where this is not so certain), and should be worth more for a surveyor, insurance company or buyer.