Repairing caulking how to do it ? Help needed

[sallygreen]

Ive now after much effort stripped my maghony carvel planked diamond yacht down to bare wood, the hull is in good shape however some of the caulking is crumbled a bit in places, what should I do, Ive sailed the boat extensively for about 3 years with no leaks at all,
I need some help on what I should do ?

 

[EASLOOP]

Do you use conventional caulking or synthetic? If conventional then it will be cotton caulked backed up by red lead putty (below w/line) or white lead above.
I used a file tang bent over and sharpened. Carefully rake out the loose putty leavidng the cotton in place. Simply mix up a splodge of goop and press it into the spaces left from raking out. If cotton is worn out ( a lot of mine had turned into strands of black hair) it will need to be removed back to the good stuff and re-done. Don't overlap the cotton though as you could end up with a hard spot and persistent leak when she takes up.
If you are using synthetic then I 'aint got a bl**dy clue.
I completely recaulked my East Anglian, decks and all. She is mahogany on oak with a laid teak deck.

I am sure there are lots of other opinions out there.

Good luck

John

 

[joliette]

Yes, rake out the crumbling stuff. You'll find that some of the putty will be stuck to one side of a seam and broken away from the other. If you put red lead putty back in then don't rake out the side of the seam that's still intact, just leave it as is and push the new putty into the gap. I find that a narrow wire brush is a good tool for cleaning out seams.

You could also use Sikaflex 291. However, to get this to stick, the seams need to be clean, dry and primed. Blakes Woodseal works well as an alternative to underwater primer. Any dust or particles in the seam just glue to the Woodseal and as soon as the Woodseal goes tacky in the seam you can squirt in the Sikaflex. This method also works well on the seams of teak decks and is much cheaper then buying Sikaflex primer for 290DC!

 

[Porthandbuoy]

[ QUOTE ]
. . . the caulking is crumbled a bit ...

[/ QUOTE ]

First check just what is crumbling. If it is the stopping (read/wite lead putty) then carefully rake it out without disturbing the cotton caulking underneath.

Second, check the state of the caulking itself. On a yacht it is more likely to be cotton string than oakum (hemp fibres soaked in stockholm tar). If the cotton is still fibrous, stringy and intact, harden it up with a caulking iron and a mallet. 'Simply' hammer it back into the seam, but not so hard it protrudes on the inside. If your caulking has the consistency of potting compost, like mine did, you will have to replace it. Caulking irons and cotton can be obtained from Traditional Boat Supplies - 01502 712311. or you can improvise.

I am not a fan of synthetic caulking compounds for a variety of reasons:
1) They don't stick well to wet or oil impregnated wood. And I don't care what anyone else says.
2) It can pull away in long sections, which lets in lots and lots of water!
3) And most importantly. When your boat is launched and 'takes up', the planks will swell, compress the cotton, stop leaking, and the whole hull will stiffen up (well mine did, except for the leaks bit).

Third. Finish off by stopping the seam with red/white lead putty. Mix a fingernails size bit of grease with a fistful of putty to stop, or at least delay, it going hard. Squeeze it into the seam with a 1" scraper or similar. Purists will tell you to use red lead below the waterline and white above.

Best of luck

 

[Peterduck]

Be very careful about how you 'hammer' any cotton caulking back into the seam. A Y.W. Diamond will be very lightly built, and it will be very easy to overdo the hardening up of the caulking, thereby damaging the edges of the seam. I f you are just repacing the stopping, prime the seam with Red Lead before working the putty in with a spatula.
Peter.