Sprung planking.

[Biddy]

Having just aquired a 2 1/2 ton Hillyard I have a problem which I'm hoping the skilled amoungst you might be able to offer advice on.
The boat has sprung a couple of planks - above the water line - at her bow. They have sprung off the first rib and only slighly off the second rib - still attached from there on. She is due to come out of the water soon to be TLC'd and obviously 'unsprung' !! What is/would be the best way of resolving this problem, how best to fix it ?? I am confident enough to be able to repair her myself but just need to know the best way forward .... would love to have a pro do it, but like most 'yachties' have champagne taste with beer money only. Besides, I prefer the satisfaction of doing a good job myself !!

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[johnlilley]

When you say "sprung" do you mean the rivets have pulled through the plank or stretched allowing a gap between the plank and frame or are you perhaps meaning the hood end (front of plank) has pulled out from the stem as is possible with Hillyards as they are only copper dead nailed into the stem and can get loose if the stem timber is allowed to dry excessively. Is there any damage to the plank and or frame? Has she been overcaulked in the area recently? A bit more info might help. I am sure there will be plenty of forthcoming advice......all free!
Regards John Lilley

<hr width=100% size=1>John Lilley, John Lilley & Associates, Web site www.seasurveys.co.uk for osmosis /timber problems

 

[Biddy]

From what I understand the bow took a 'bump' as she was being towed, as a consequence a couple of planks have 'pulled' off the rib. I think, again from can be seen, that the heads have probably 'popped off'. Also the planks have come 'adrift' from the stem post - about 10mm.


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[Mirelle]

Here is what I would do. But be warned I am only an amateur!

First, look to see if any ribs are cracked in way of the damage.

Next (I know this sounds odd!) look for damage diagonally opposite the damage that you have found. (Think of a rectangle getting hit on one corner and getting squashed into a parallelogram and you will see why!)

If the damage is near the deck, have a good look there too.

If all is well, reef out the caulking in way of the damage and for one strake either side of the damage, pull the old fastenings out, cutting the heads with end cutters if you need to, then clean out any bits of paint and other dirt from the good end area, using the end of a broken hacksaw blade or whatever comes to hand.

Now apply copious amounts of bedding compound (not Sikaflex! You may need to get the plank off in the future!) pull the plank ends in with cramps (this can be very tricky - if no sucess - get a friend to lean on the strake!) and refasten with screws. Then refasten the rib(s) and finally recaulk and repaint.

<hr width=100% size=1>Que scais-je?

 

[Biddy]

Many thanks Mirelle, will take all 'onboard' ... sorry don't normally talk with puns but hey when in the boating world !!

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[Forbsie]

How are the topsides?

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[Biddy]

The topsides are all in 'good nick' no obvious signs of damage or pieces parting company ! All the damage seems to be centered at the front with an 'A' shaped piece of timber immediately underneath the bow deck/attached to the stem post having a split straight through it ... not sure if it split because of the bump or if it has been there a while ?

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[Peterduck]

The "A" shaped piece of timber is called a breasthook, and is intended to keep the two sides together. It is a fundamental part of the hull structure and will need to be repaired. Replacement would be a terrible business involving a lot of dismantling of the boat around the breasthook. I would think about boring a hole transversely through the breasthook and the planking outside it, clear through and open at both ends. Fit a length of allthread through the hole with triangular pads at each side on which to bed the nuts and washers. Bring the two sides of the breasthook together by tightening on the nuts before gluing and screwing a triangle of stout plywood upwards to the underside of the breasthook. If it is posssible to inject epoxy resin into the crack before closing it, so much the better.
When the epoxy has cured, replace the allthread bolt with a tight-fitting trunnel with long tapered wedges at both ends. Plane off the ends of the trunnel smooth with the planking. This is why the wedges need a long taper - so that you don't plane them away afterward. The further aft that you can place the trunnel [and still be in the breasthook] the more effective it will be. The wedges, of course need to be aligned across the grain of the planking so that they do not split it.
I would also get a shipwright's second opinion on the repair method. There is usually more than one way to skin a cat.
Peter.

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[Porthandbuoy]

Check the bolts holding the stem pieces together. Mine were all corroded through which allowed Mariposa to work so much that the planks simply worked loose. I've bolted the stem back together and am about to start screwing the planks back into place.

<hr width=100% size=1>"Mariposa"
This time next year; maybe.