View Full Version : Repairing split planks
09-28-2010, 10:06 AM
I have a 50 year old 17' Shetland yawl, larch on oak that has several splits in the planking, both below and above the water line. Additionally several seams are leaking.
This winter I plan to strip off the paint back to bare wood, dress the seams with Sikaflex and spline the splits.
I have the following questions:
-What proportion of the plank thickness should be routed out (planks are approx 12mm thick), and what width? Square section or triangular?
- Can I use square or rectangular section wood that can be bought in DIY store (such as used for beading), given that it will be sealed and painted? I read somewhere about a triangular section being used in a square channel.
- What would be the correct adhesive to use?
I would be grateful for any advice on the above, or pointed in the direction of a book which has this information.
09-28-2010, 10:18 AM
What is beading???
I do not think any wood from a DIY store is worth using on a boat.
Lets see what the experts on this forum say.
Why not just not stuff cotton in the split?
How wide is the split?
We need a photo.
09-28-2010, 10:24 AM
Shetland Yawl, this is a clinker boat?
A little (recent) history por favor. Pics too.
Why the splits, has the boat just dried out?
09-28-2010, 10:55 AM
I haven't got any photos to hand - I'm at work at sea for the next few days - however the attached link should direct you to the original advert with pictures.
The yawl is a double ended clinker boat with a small inboard diesel and a dipping lug sail. I acquired the boat at the beginning of this year, but have done very little to her, on the basis of using her for a season to see how things work.
This type of boat has widely spaced ribs - only 5 in total. I think one of the splits may have occurred due to a side impact at some time, and another because a couple of floor boards were resting on the planking rather than the ribs. They are not instantly obvious, being noticable because of the cracking in the paint and could probably be left, but as I am going right back to bare wood I thought it would be timely to address them.
The boat has been in the water continuously since April, so all planking has fully 'taken up'.
Beading, by the way is a thin strip of wood, can be square, rectangular or triangular, used to finish off edging in woodwork. I was thinking along the lines of 5mm square softwood bead - flexible and kiln dried.
09-28-2010, 11:41 AM
I believe that is the type of boat that Paul Johnson first sailed across the Atlantic. His was 18' and at the time , around '56, it was the smallest boat to do so. google, Paul Johnson Venus Ketch
09-28-2010, 12:07 PM
So far as the repair of your plank splits are concerned, the critical factor is whether or not the splits go all the way to the hood ends at the bow and stern. If this is true, then you are better off replacing the split plank. If it does not, splining is one choice. However, a simpler method would be to force Gflex epoxy into the splits either with a gun or by putty knife. a hole should be drilled complety through the plank at the end of the split in order to prevent it from cracking further. The Gflex epoxy will give a little and hold the plank from splitting further. The holes can be filled with a cedar peg that is also set in epoxy. Some modern seam fillers are not as effective for use on traditional planking as the traditional ones are. In your case, I would opt to use oil based seam compound rather than one of the modern sealants.
09-28-2010, 12:18 PM
Many thanks for all the advice.
The splits do not extend for the whole length of the plank - generally they are about 300 - 600mm in length. The Gflex epoxy mentioned - will it soak into the wood as the splits are almost hairline?
09-28-2010, 12:40 PM
She looks like an old Shetland Model racing boat, possibly Maid class. How many planks are split? The traditional method of repairing in the Shetland Isles was to fit a wooden tingle over the split on the inside. Peerie Maa has loads, like these http://i408.photobucket.com/albums/pp164/peerie_maa/Idiot%20proof/DSC01047.jpg
Use 10 or 12 mm larch for preference, but if you do not have a source of larch near you, marine ply will do just as well. Bed them on a flexible sealer, and screw or clench round the edges and along both sides of the splits.
09-28-2010, 12:53 PM
I understand from her previous owner that she was built for a Shetland fishing boat skipper as his run around, and have a photo of her loaded with creels.
Thanks for the advice on tingles - seen them before but did not know they had a special name. They would certainly beef up the strength of the sides.
09-28-2010, 03:04 PM
It's also worth noting that most epoxies require the wood to be fairly dry (below 12% maybe?) to soak in and get a grip on the wood, so that could be a problem, especially if the splits open more as she dries.
09-28-2010, 04:10 PM
Indeed, Bill makes a good point. The boat should be dried down to 12 or 14% moisture content for the glue to be effective.
09-30-2010, 09:30 AM
Gentlemen (and ladies if any),
Many thanks for all the sound advice, and highlighting different methods which I had not considered before.
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