Sheer Strake question

[lesweeks]

My restoration project is carvel; Pitch Pine on Elm. So why is the top, sheer, strake mahogany? I've looked at similar old boats and they seem to be the same. Even though it's 100 years old (nearly) the Pitch Pine is rot free throughout. The mahogany, however, is so patchy rot wise where the rubbing strake and decking is attached that I think I'll end up replacing large sections of it and evidence suggests that some parts have been replaced before.
Anyone know why?

 

[Peterduck]

Generally, hardwoods [eg, mahogany] will hold screws better than softwoods [eg, pitch pine]. Don't forget that when the boat was built, 20 years was its expected lifetime, so the durablilty of mahogany was quite adequate for that length of time. There may have also been a matter of bright finishing the sheerstrake, if the commissioning owner liked that appearance.
Peter.

 

[grumpydog]

I'm no wood expert, but I've come across yachts that use a few different types of wood in their planking. Pitch pine is really a diva of planking wood, but mahogany is (or was until everyone found out it rotted like billy-oh) considered better for planking above the waterline as it's more stable than pitch pine and less liable to crack the paint off. Pitch pine is wonderful below the water because it's happy to flex around a little. My boat is pitch pine planked all the way and like yours, there has been not one iota of rot in 76 years. Other woods on the boat have suffered rot (particularly the elm in the keelson and deadwood).

 

[Seanick]

Yup, just because it looks nice varnished, end of.
Mahogany is pants!