Author Topic: clinker 12 construction clues  (Read 329 times)

PAR 12

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clinker 12 construction clues
« on: November 01, 2018, 03:52:34 PM »
Hello All

Vintage construction help

I am trying to cure an annoying leak in my 1967 Wyche and Coppock Mk14 around the garboard/hog joint

From underneath I can see damp timber in places along the keel/hog joint
I was planning on reaming out the solid timber CB case sides/hog/keel assembly by 6mm each side to a depth of 65mm and then line the widened area with marine ply and subesequently  seal the interior plank/hog joints.

Before I do this I'd like to know how others have approached similar issues. I'm concerned  I may  come across hidden screws in the original build.

Any ideas out there?   I really do not want to have to remove the whole cb case out of the boat.

thanks

Paul

martin 1262

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Re: clinker 12 construction clues
« Reply #1 on: November 01, 2018, 06:48:01 PM »
 Hi Paul
 As Someone who has owned three vintage Wyche and coppock national 12s I think Iím quite well-placed to understand the problems you are facing. From my experience the solid wood especially hog keel and centreboard case tends to be the weak parts in the boat. They are vulnerable to time in dinghy park and water getting in under the cover. I have found however that the plywood planking that was used seems to be of very good quality and was able to stand the test of time. You will find when you start peeling things back that the boats are held together with glue and steel screws!! so be careful if you start to cut away with power tools. Whilst it is tempting to patch the centreboard case and hog with new pieces of wood inevitably you will come across recurring issues over time and the only true way to overcome this would be to remove the keel and the hog as much as you can and replace the case which is not an easy job. Brian Herring is a good contact if you want some advice his number is in the book.  Good luck Martin Clarke ex 2306 2708 currently 2576
« Last Edit: November 01, 2018, 06:49:37 PM by martin 1262 »
 

PAR 12

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Re: clinker 12 construction clues
« Reply #2 on: November 02, 2018, 12:11:48 AM »
Hello Martin


Many thanks for the advice.


I feared the problem may need more extensive surgery as you suggest, but I was hoping to do the minimum disruptive work necessary to effect a watertight repair.
I'll see how  It goes


Thanks again


Paul




Chadders

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Re: clinker 12 construction clues
« Reply #3 on: November 03, 2018, 02:46:04 PM »
Just a thought and something that Donald Acklam did to my Starfish and on his own Starfish that seemed to work.  We removed the keel band and used a routing tool similar to a countersinking bit to cut into the joint where the plate case sits on the hog.  I think we cut in by around 6mm leaving a V shaped groove.  After through drying out this was wetted out with SP epoxy and then filled with a stiffer mix of epoxy and smoothed off.  It was perhaps a bit of a bodge but it worked!  As Martin says the screws into the bottom of the plate case and hog are often steel ones on the Wyche n Coppock boats and maybe others as well.  Hope it helps. 

PAR 12

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Re: clinker 12 construction clues
« Reply #4 on: November 04, 2018, 03:17:31 PM »
Hello there


Many thanks for your reply


Your description  is quite similar to what  I was thinking of. 


Its reassuring to know that your solution worked.
 
I'll proceed with caution - trying to avoid too many steel screws!


Thank you


Best Regards


Paul

Rod & Jo

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Re: clinker 12 construction clues
« Reply #5 on: November 05, 2018, 06:47:43 PM »
To add to what other have said. We had this problem almost 30 years ago with our 1965 W&C built Merlin, & subsequently discussed the issue at the N12 75th event dinner with the person (I now forget the name) who may well have built the boat, and confirmed as follows:-

At that time, the CB case was fixed to the hog with plain steel screws from below, then the external keel glued on over the screw heads. In time, the usual forces on the CB case open up the glued joint between that & the hog, water gets to the screws, and you can imagine the rest.

What I did was chip away the external keel to expose & remove all screws until I could lift out the case, clean up this & the hog, rebate in, reglue, & fix with s/s screws, & finally glue on & shape new external keeL

Yes, a lot of work & I appreciate you want to avoid that, but IMHO it is the only permanent solution, which has amply stood the test of time in our case,- the boat has been sailed a lot & remains bone dry. Fixing fillets (epoxy or wood) along the case/hog join is a quick fix which will work if well done, but I think condemns the boat in the long term, since the failed joint will always take on water from outside & rot further, away from sight.

Hope this helps.

Rod & Jo

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Re: clinker 12 construction clues
« Reply #6 on: November 05, 2018, 07:04:37 PM »
I should have added, Donald A both originally built & much later helped restore (with Tim Gatti) our N12 3109. I never met the gentleman, but he sure knew about woodworking  (see boat data base).

However, this does not alter my conviction that a fillet job is a quick fix but condemns the boat in the long term. Might be perfect justifiable,- depend on what you want!

R

martin 1262

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Re: clinker 12 construction clues
« Reply #7 on: November 05, 2018, 07:41:24 PM »
Hi just to add to what has already been said.  I know Howard looks after Triarda so well and as a result the work done will last a long time. I had 2306 Starfish filleted also by the hog and centreboard and sold her in tip top condition. When I had her back again 4 years later she was in a very sorry state and the water sitting in the hull destroyed the wood around the filleted pieces so in the boat was pretty close to being scrap. If you look after the boat and itís done well you might well get a good outcome. Hope it goes well whatever you decide !!
 

PAR 12

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Re: clinker 12 construction clues
« Reply #8 on: November 06, 2018, 08:28:48 PM »
Hello  All


Thanks for the further guidance.


I have today started


keel bands off
guides on
routed out  63mm deep  4mm approx extra slot width per side


the photos show  (hopefully)  not too much damage
A few steel screws bit the dust - which can be replaced with stainless.


Next after complete drying out will be sleeving the  slot and that should cure the ingress of water into the boat
Then I just have to sel the hog/plank joint inside the hull - which I'll probably use a dremel and let in a mahogany strip - then hopefull both sides of the leak will be fixed


Sounds easy in words -well see how it goes


I know it may not be the pure solution but as the case to hog joints are good  I am loath to remove the case if its not really necessary


thanks for all your advice.


Best Regards


Paul


 
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