Filling the seams again

[lesweeks]

Having removed all the caulking from the seams of my 1912 yawl (pitch pine on elm) I now have to decide what to fill them with.
So to set the scene; Some of the seams are very wide - 1/4" to 3/8" in places - and the original cotton was pushed right through here and there. The boat is very dry having been ashore for seven years or so and under cover for the past 12 months, but the big gaps were obviously there before as the gaps/cracks in the putty were small and there was lots of cotton. Many of the plank edges are damaged where, I guess, previous similar work has been done over the years. I'm about to start hardening up the fastenings, replacing those that need it.
The choices as I see them are:
1. Splining (only above the waterline), recommended by a number of 'advisors', glued with epoxy, which will give a tight, smooth and tidy hull, with no ingress of rain water and less maintainence. But will it burst the fastenings when she takes up? Pitch pine splines or something softer that'll give? Will the splines themselves shrink in time and tear away from the planks leaving a greater problem? And is it really in keeping?
2. Caulk traditionally - Cotton or Oakum. I know that 8 ply cotton is available and that would be replacing like with like, but some advise that for the big gaps oakum would be better as its grip is stronger. Someone suggested oakum with cotton on top as the cotton expands more and gives a better seal. I've never done it but with 1000 foot to, do I'll learn! Traditionally sound, but does that make it a better choice?
I'm changing my mind as often as I change my socks at the moment. Any views and suggestions welcomed. /forums/images/graemlins/confused.gif

 

[alan006]

I have not used the splinning technique so I can't really comment on that. If in doubt I always replace like with like. My guess is that you are right to be cautious about possible problems with movement.
Hope you get some more helpful comments.

 

[Peterduck]

Were the task mine, I'd be tailoring splines to the seams adjusting the thickness as required to bring the seam width back to a more acceptable one. Glue these splines to the lower plank only, and hold them in position with tiny wedges while the glue sets. These should ensure that the seams taper to a relatively tight fit halfway through the plank thickness. I know that it's a fiddly job but the boat is worth the effort. You can use this method for the full depth of the hull. In the case of the garboard seam, the most critical one, I'd glue the spline to the plank rather than the keel. I'd use Oregon Pine for the splines, as it will hold on to the glue better than Pitch Pine. The usual caveats about gluing to Pitch Pine apply, too. The first caulking should be done with a light touch; just enough to get a seal and to harden up the planking to a cohesive unit. You can harden the caulking after the boat has been afloat for a season, if you think that it needs it. To paraphrase an Old Saw, "if it don't leak, don't fix it!"
Peter.

 

[lesweeks]

Thanks Peter. When I sat down to compose my post I forgot the third option! Someone else referred to this as splinting.
There isn't a seam on the boat where the planks 'taper to a relatively tight fit.....' and so every seam would need to be done. The old putty has been cleaned out but the edges of the planks are very difficult to get clean enough to accept glue. I guess this is why cutting a new surface with a router or biscuit cutter seems an easier, practical idea.

 

[EASLOOP]

I'm with peterduck. This is the method I used and my carvel planked boat had been ashore under tarps for 14 years!! I now sit on her at her moorings blowing the dust from the bilges (well, apart from a tea cup full of water each week).
Good luck. It's quite a long job but one well worth getting right.

 

[sue_bagnall]

Have you thought of wetting her out from the inside? This will allow her to take up quite a bit. Use see water with old blankets soak the blankets and lay on the planks. If you cant do it in the inside try hanging the blankets on the out side hold in place against the planks soak with see water. You will be suprised how much she will take up. Then recaulk and pay up. I have done this in the past when our boat had been on the hard for a few years.
Rgs
Sue