Mahogany boat....drying out

[gary3029]

I have a wooden boat 24ft. Have just brought it out for 8 weeks to varnish and antifoul prior to season as I used it through winter. The hull is mahogany clinker planks on oak timbers and mahogany rudder. Does mahogany dry out quickly and is it prone to cracking when dried out. How durable is this type of wood in sea water as I noticed some exposed bare wood ?...does it rot easily?

 

[johnlilley]

Mahogany , like any timber ,will dry out eventually, but it would take longer than 8 weeks this time of year to dry out substantially,6 weeks in June/July will do more damage than 4 months November to March. It should take up naturally back to where it was before lifting out within 24 hours.
Mahogany is fairly durable below the waterline (seawater) but fresh water affects mahogany eventually over time, but not weeks. Best to prime any exposed area though.

Hope that puts your mind at rest.
John Lilley

 

[oldharry]

8 weeks shuld not make a lot of difference, though she is bound to take up a little in the first few hours after launching.

Timber is an organic material, and will deteriorate if not protected. Not ony will the surface weather and become cosmetically unsightly, but it will be more prone to attack from woods natural enemies - rot and fungus as well as insect and marine borers. End grains are particularly vulnerable. A good paint coat will always protect and extend the life of the material.

Also if there is bare timber showing, it will allow entry to moisture under the surrounding paint coat, and will lift it off.

 

[joliette]

Some good advice here already. Below the waterline make sure that any bare wood is protected with 3 or 4 coats of primer and a top coat of antifouling. Sea water "pickles" so the only rot you'll likely to see below the waterline will arise from electrolysis (where you get electrochemical decay from disimilar metals adjacent to each other in the mahogany e.g a copper boat nail and galvanised steel bolt). The wood will go black and soft if this is going on and eventually you'll need to put in a graving piece (a repair patch). With rain water you need to keep it out of the boat, so make sure that the decks are well sealed and the scuppers are clear. If rain water is getting in whilst she's ashore then take the drain plug out of the keel and / or put a tarpaulin over her.