Hull caulking

[cswan]

I am about to start re-caulking the hull of my 30ft carvel hull, as it has been out of the water for some time the seams have opened up (upto 6mm) it has been suggested that I soak the hull first to close up the seams is this a good idea?

As i have not done this before any advice would be good.

 

[Porthandbuoy]

Re-caulking just because your boat has been out of the water for some time is not a good idea. When you put your boat back in the water the planks will swell and the seams close up. It's a bit worrying at first watching the water pour in, but she will take up in time. If you'd closed the seams up with new caulking then you could easily be faced with broken frames and / or planks pushed out of place.

If the caulking is rotten, or has fallen out, then it will need to be replaced; in which case a few weeks in the water will tell you where the problem areas are.

 

[cliffordpope]

If the seams have 6mm gaps the boat will sink before they close up, unless you have extremely powerful and reliable pumps available for the next month or two.
There really does seem to be a problem here, and no one has come up with an easy answer. What's needed is some kind of simple way of pre-soaking a hull for a month prior to launch. I suppose if near a source of water (preferably salt) a pair of garden sprinklers would work. Just dowsing with a hosepipe isn't goingto be nearly long enough.

 

[boatbuilder]

I have used wet sacking in the past and it seemed to work, but it will take a couple of weeks. Try it before re caulking, as has been said a lot of damage could be caused when the planks take up on the new cotten.

 

[cswan]

I think I am missing somthing here, If I soak all the planks I am sure she will close up just leaving the original leaks. But if all the timber is then we how do i paint it and will it not then rot. also, should I paint her inside (bilge) as this has never been done. I should also say that apaert from the odd leak the reason for her to be out of the water is a lot of rotten frames that I am replacing along with the deck, several deck beams, wheelhouse, floors, sole, parts of the bilge stringer, and all the cabin fixtures lockers etc

Plastic boats must be less work.....

 

[pirate]

i am going through exactly the same dilema with a hillyard.
the boat is being reframed and so has dried out before even starting on fitting new frames.
unfortunaetly the boat had been overcaulked in past and has led to broken frames and the planking opening up.
all the books say to pull this back together but if i pull the planks till they touch i will generate a gap of about 5 inches and the frames would crack on taking up.
so i put a piece of dry 5 x 1 pitch pine in a bucket to see how much it expanded and guess what it grew by a total of 6 mm 1.e. 3mm from centre line so it would appear that when your hull takes up the planks will just touch.
it took this plank 4 weeks to swell to this size so if you could water your hull for this time it may help although the test plank was permanently in water.
i now have some pine planks with foam,sacking and newspaper on to see how quick they expand.
the only ideal way if the boat is stripped and you have a crane and sea is i'm told to sink hull for a few weeks take out fix in about a week and put back in!!!!!!!!!
some experienced boat builder out there must have another idea.
good luck

 

[mclark]

In the past when faced with planking opening while ashore I have just shoved soft putty in the seams and put her in the water - obviously dont go sailing but the putty temporarily will keep the water out whilst squeezing out as the planks take up. Adding sacking or carpet hung down over the sides into the water to wick up moisture will also help the topsides.

 

[cliffordpope]

Boatbuilder has a good point there. If a boat ideally is never allowed to try out, how is it ever repainted? Or is it OK to paint soaked timber on both sides?

 

[cswan]

I think the key to this is how much swelling takes place for a given timber. However, When boats are built do they use seasoned timber, which was caulked and painted and in theory or did not get wet, or did they use green stuff that was already wet?

Also, Do I then have to rivet the new frames in loose as If a plank gets wider will it not therefore also get thicker?

why is this so complicated.. Does the hose pipe ban cover making your planks swell.