Chalking lifespan.

[4nd7]

Caulking lifespan.

Just looking to take on a project and was wondering what the best guess lifespan would be to the hull planking caulking.
I appreciate there are many different factors that could effect this and a bit of "how longs a bit of string" question. But the basics are, neglected for 7 year, extensive restoration beforehand, pine planking with oak ribs, readily drying mud berth, probably 50/50 wet/dry, covered in Barnacles. Slightly salty bilge water present.

Any advice appreciated.

 

[Keith 66]

Its called Caulking! Not enough info, what sort of boat & what construction is she?

 

[4nd7]

Thanks, embarrassing spelling corrected hopefully.
The boats is a carvel built gentleman's cruiser, 40 foot, guessing around 12 ton.

 

[Ladybirdgaffcutter]

One thing to bear in mind:

Caulking is not just for keeping the water out of the boat by blocking gaps between the planks.

It is part of the structure of the boat, because it provides a controlled amount of rigidity.

Too free a movement of the planks with too-soft caulking would weaken the construction very quickly, it would just fall to bits.

Too-hard caulking will not allow the planks to expand and contract in different temperatures and levels of dampness. Wood expanding when it gets wetter is a very powerful force, easily enough to rip the fastenings out of the ribs.

If you look at a video, or get lucky enough to watch a shipwright caulking a boat, the exact force he uses on the mallet is very important, as well as what he uses.

So please be careful, don't rush in and start using sealant or sikaflex etc.

How long it lasts is as you say, a piece of string q..but it needs redoing sometimes..

 

[Kukri]

Agree with above.

If she isn’t leaking, the caulking is fine. The place where it may not be so good is in the topsides if the seams have opened and stayed open; rain water gets past the cracked putty and rots the cotton.

 

[Keith 66]

Hopefully she had a proper restoration but 7 years is a long period of neglect. Rot usually starts from the top down with freshwater ingress. If she has a raised foredeck & lower side decks the transition area is a common place for rot to be found in boats like this. Also check behind dead air spaces in showers or heads compartments.