Vintage Boat Advice

[benb]

I have recently bought N1851 which is my fifth twelve but my first proper 'old' boat. Having spent a bit of time having a good look at her I have concluded that she definitely is in need of some TLC - but nothing too serious. I'd appreciate any advice from those with more experience than me. I've listed out my main worries (for now).
 
1. The centre board case has signs of enough rot near the floor to warrant replacing. From what I can see without removing the case the hog and keel look sound though.  
 
Does anyone have any tips for replacing? My initial thoughts are to carefully remove, clean up the hog and keep, use the old case as a template for the new one, and rebuild from there.
 
Anything else I need to think about?
 
2. Quite a few planks have been sealed with bathroom sealant - to my mind this seems a bit strange but I thought I'd check that this is not a ‘vintage’ trick.
 
3. On the whole she feels a bit fragile / flexible and I think this may be as the joints between the planks are flexing more than they should. I think this is due to the fact the planks are not securely glued but also : -  

It appears a front bulkhead has been removed at some point roughly where a buoyancy tank would be in a more modern (four plank) boat. 
 
The side seat (I don’t know what you call it) has been shortened at the thwart and I assume it originally extending further aft. There is evidence of another set of knees about 2 foot forward of the transom which I assume would have been where the seat would have terminated. Or may have been an aft tank?
 
To my mind these things will all have an impact on the overall stiffness of the hull but have probably been done to save a bit of weight.

I appreciate this is a bit vague but any advice welcomed…  Especially in the order I should attack these issues?

Cheers
 
Ben
 
  
 

[Chadders]

Firstly congratulations on buying an older 12 not least because vintage 12 owners are the most helpful bunch you could ever wish for and I have no doubt you will get lots of feedback and advice for my part-
1  The man to ask about your plate case is possibly our Chairman Tim Gatti or boat builder and member Brian Herring whi has done lots of these, currently he has a similar job in hand and he is helpful with advice, even better if you don't fancy it you could cross his palm with silver and he will do it for you.  All contact details are in the class association yearbook
2  Bathroom sealant is not a vintage trick although duck tape works as a temporary fix but basically you need to do a proper job with epoxy but only after getting rid of all traces of sealant or it wont stick.
3 She should not feel all that fragile and vintage boats often have front tanks which may be half or full hieght, mine has a half tank in and in addition to stiffening things up it stops all the water which when full flows under the bow bag and causes all sorts of nose diving problems.  Side seats were again done to the front and rear of the thwart or sometimes just to the front.  This should not make too much difference to the fragility of the hull as long as the shell is basically sound.  I would start with what sounds to be quite a lot of sprung planks and see how she feels when these are all done.  The plate case is a fairly big job and I personally have not done the job. 
Hope that helps a little if I can point you towards more help give me a call again I am in the book.
Howard Chadwick Vintage Wing Representative (aka Chadders)

[benb]

Thanks Chadders - Im pleased to have a boat in the garage again. 
I remember Brian from past times in the fleet so may give him a shout.  I'm glad you have confirmed my suspicion on the bathroom / kitchen sealant.  Previous owners clearly had quite a selection as there's clear, white and brown in various locations!!  I thought the brown version was epoxy and microballoons until i touched it and found it was all rubbery! Unless it is and actually someone got the mix very wrong. At least it hasn't stuck to the varnish too well. Other than that and a bit of rot she is sound and has obviously been well cared for and fairly recently someone has spent a few quid on a very nice cover, decent strings etc. 
Annoyingly I cancelled my subscription to the NTOA last winter in a moment of supreme tightness - time to renew I think.
Here's to a winter of gluing, sanding, more sanding and maybe a bit of painting towards Feb if all goes well.
Cheers
 
 

[FuzzyDuck]

Just a thought if you are going to change the centreboard case. assuming you have a metal centreboard, it may be the ideal time to widden the slot and go with a wooden one. 

[benb]

Fuzzyduck 
I was thinking about that option as the current case is solid wood (metal plate) and I thought that it would be fairly easy to make  thinner replacement case out of an alternative material i.e. ply which would allow a thicker wooden board. My only issue which I havent really thought through yet is whether making the slot wider would end up requiring changes to the keel band also. I haven't looked at it with that in mind yet - thats a job for the weekend - but even if it did it shouldn't be too challenging.
So many possibilities!  

[Tim Gatti]

As Chadders suggests - might be worth having a word with Brian Herring as he is just in the process of rebuilding the case, hog and keel on N1833 Water Nymph - a Mk 9.  Have a look at the pics in the boat database to get an idea of the work involved.  If the hog and keel are sound then I'm told you can use a chain saw to widen the slot but that's always sounded a bit brutal for my liking.  Alternatively you could alsways replace the galvanised plate with an aluminium one and save some weight that way.  I did that on N341.  I've also got an alloy plate in N493. Bathroom sealant is definitely to be avoided but a selective use of marine sealant like Sikaflex 291 can often work wonders - particularly on a ribby where you don't want to start gluing it all together with epoxy. Post some pics when you can. Tim

[benb]

Thanks Tim
Thats really great as I have some how managed to miss the pictures of 1833 going up on the database but they will be a useful reference. Will try and post some photos tonight.
A chainsaw does sound a bit 'aggressive' but then I use to think that about angle grinders a few years back. I'm still not sure I'd trust myself with a chainsaw though...

[benb]

I've added some photos on the database section under 1851.
Any views on resolving delamination issues like this? Theres a few patches like this.
  
  
 

[johnk]

The seam sealant looks like a silicone one. You can get (from B & Q) a silicone sealant softener which might do the trick. Then clean out the joint and use epoxy. Wyche and Coppock would have used Aerodux (phenol-formaldehyde) to glue the joints originally.

If you are concerned about the state of the top veneer of the plywood, scrape the varnish off and dry properly. I would then coat with a low viscosity epoxy mix to fill and fix the crazing.

Others with much more experience may well give better advice.

[Tim Gatti]

Ben - I had similar 'rippling' on my Mk 12 earlier this year.  If you can summon up the courage to do so have a look at my posts on the Boat Database - N2255 - Purely Platonic.
It may just be top veneer that's the problem, but often the rippling is caused by damp incursion from the edge of the plank which softens and rots out the core sections of the ply. A problem that only becomes evident once the internal damage is done and the planking is terminally damaged.  Your only option is to investigate throroughly with a sharp instrument - a bradawl, corner of a sharp chisel etc to see whether the ply is solid under the top veneer.
For your sake I hope it is - but at least you'll have my pictorial guide to effecting a repair if it's not. Good luck. Tim 

[benb]

Gulp! followed by sharp intake of breath through gritted teeth. I'll get the chisel out and report back...
Fantastic photos though Tim what a great looking boat. If I can get anywhere near that standard of 'end result' I will be very chuffed.
 

[benb]

Good news (for me) the vast majority of rippling does appear to be cosmetic and just the top veneer - there are three patches that will require more dramatic action when the time comes and Tims photos will be useful then.