Wooden boat caulking

[brownings1]

I have a 1965 27ft 6" carvel cabin cruiser which is kept on a marina mooring on the river.
It's a very good, dry boat but there are just a couple places where water seeps in. Although difficult to be specific, I think one is from the garboard seam near the bow and the other along 2 or 3 of the plank seams on the port aft quarter about one third way up from the keel. Total incoming water is averaging at about one third of a rubber bucket a day so nothing to be too worried about. The hull shape is very shallow so a pump won't suck it up and I therefore have to soak it up with a sponge, which is a bit of a drag .
My question is - why does the amount of average daily leakage vary so much? - between say up to over half a bucket a day at some times down to sometimes much less than a quarter at other time, for no apparent reason. The boat is entirely covered when not in use and the amount coming in is definitely not affected by rainfall, ambient temperature, or whether or not it has been used the previous day etc. Has anyone got any bright ideas?

Second question (possibly related?): I got the boat via a very professional and well known wooden boat repair yard. He says he caulks in the seams on wooden boats using a West epoxy resin/hardener/microlite filler mix and did so on mine. He says that Microlite has adequate flexibility. Has anyone got any views or comments on this technique? I have to say it appears to be very effective on 95% of my boat but I'd be interested in what others have to say.

Thanks

 

[ccscott49]

I wouldnt use epoxy filler for any seams on a boat, in fact never even heard of it before. I've heard and seen, cotton caulking and putty (red or white lead), cotton caulking and sikaflex, I would have thought epoxy would not be flexible enough.

 

[EASLOOP]

I have a 28' wooden sloop, circa 1962. She is carvel planked. I would never put epoxy in the hull seams. From what I have heard and read mixtures that set hard do not have enough flexibility and when the planks swell could easily crack the plank lands. I completely re-caulked my boat using twisted cotton with red and white lead putty.
Good luck

 

[Roach1948]

Microlight is a fairing compound as opposed to a filler. Its designed to be easily sanded and not for gap filling. Leaving aside the argument of whether epoxy should be used or not for trad boat caulking, I think your boat builder has used an inapropriate epoxy filler and maybe this is why it has failed in a few of your seams.

 

[Peterduck]

Are you sure about where the water is coming in? Is it possible that there is another, unsuspected, leak just above the waterline somewhere. When other boats pass and your boat rolls in their wake, such a leak would be immersed. This could give rise to a variable inflow. I concur with the views of other panellists, that epoxy should not be used in the seams of a carvel boat. At all. Caulking would have to be the most misunderstood aspect of classic boat husbandry. The traditional materials of cotton and glazing putty [with or without red lead] have been used for the last few centuries because they work, not because the world has been waiting for some industrial chemist to come along with something else. There is also a lot to be learned about the process of caulking. A good caulker is a true artisan.
Peter.

 

[old_salt]

If it helps re-do the job properly as explained above with:- this
The seller is a good ebay guy.
and welcome to the forum enjoy

 

[Blueboatman]

''I got the boat via a very professional and well known wooden boat repair yard.''
I wonder if they were using their newtech brew over the top of proper caulking cotton and as a replacement for more traditional 'Stopping' that has been used in the past in seams on top of the caulking?
If there is really no caulking in the seams(what can you see from the inside?) then I would have a word with a traditional surveyor/your surveyor...Just how many years and how much experience does the actual boatbuilder who did the work claim?
As others have said already,it seems odd.

 

[brownings1]

Thanks for all those helpful and well informed replies regarding the apparent caulking method. The suggestion that the microlite mix may have been used over traditional cotton caulking as an alternative to putty is interesting and one which I will investigate further both with the yard and when the boat is next out of the water. What would you (all) think if that was the case? The question was asked as to what can be seen from the inside. The answer is that the seams appear to be perfectly dry and tight in virtually all of the boat but in the one or two areas where some seepage can be seen they are clearly more open. What else should I be looking for? As I said before, one would normally expect to be very lucky to have such a dry boat. Finally, re the varying amount of seepage. Currently, the garboard bit has all but dried up to a spongeful. Curious!

 

[knome]

I know no one has said this, but I'll make the detail:

Caulking is not only something that keeps water out of the boat by stopping up the spaces between the planks.. it is also an important structural part of the vessels integrity. When you tap in the cotton caulking you are forming up the planks against each other a bit at a time until the whole boat is done. Caulking ALSO keeps water out of the boat when the planks dry out a bit, as it is supposed to be a bit flexible.

Seam compound put over the caulking seams is only there to do two things: (1) protect the caulking and (2) give you a smooth paint job. It is not, not supposed to keep the water out.

That being said, yards are indeed using epoxy filled mixtures as fairing and seam compounds for carvel boats. I imagine that on a boat that is painted with LPR by a pro shop, and well maintained every season, this wouldn't be too much of a problem. They also routinely saturate planks with thinned epoxy to keep down the expansion/contraction of the wood.

Personally, I'd rather use an old fashioned oil based seam compound, and just make sure she has sound frames, is fastened well and is well caulked.

 

[Forbsie]

I just started filling my seams this afternoon and was going to try the following recipe:

1 part Japan Gold-Size
1 part Best Turpentine
1 part Boiled Linseed

Mix and add to a mixture of

3 parts red lead powder
2 parts White Lead Powder
1 part Whitening (?)

I chickened out when I discovered that the gold-size was toxic to marine organisms, no white lead and what is Whitening? It can be replaced with Plaster of Paris.

I ended up just using a mix of putty, keenol and red lead powder with a dash of boiled linseed and turps. Here's hoping!

 

[brownings1]

Thank you for that - most helpful. I reckon that in my case the yard has indeed used epoxy/microlite as the stopping instead of putty. I have to say that the caulking/stopping method does appear to be very effective - apart from the one or two places where it was seeping but now, mysteriously, seem to have almost completely dried up, albeit perhaps temporarily!

On a different, but related, point I know that this particular specialist wooden boat yard often does a complete epoxy/microlite fairing 'skim' over the whole of the hull of older wooden boats (only above the waterline I should emphasize) and as a result achieves a very impressive hull finish when painted with a single pot polyurethane paint. Perhaps this isn't quite the 'done thing' but if it achieves the same result on a slightly 'tired' wooden boat that traditional seam-filling/fairing methods are laboriously trying to obtain, but is possibly quicker, probably better looking (OK, perhaps too much so), longer lasting, and certainly less future maintenance-intensive, is it necessarily 'wrong'?

Perhaps I have opened Pandora's box here!