Firefly centrecase leaks...

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ACB
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Firefly centrecase leaks...

Post by ACB » Tue May 19, 2009 2:21 pm

I assume the approved technique is to clean up the area, get it well dried, warm it with a hot air gun and run warm epoxy into any crevices? Should the epoxy be slightly thickened? Is it prudent to mask off the inside of the c/b case?

F 3163 "Aquarius",
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I14 K377 "Mercury" - long term rebuild project

Rupert
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Re: Firefly centrecase leaks...

Post by Rupert » Tue May 19, 2009 2:49 pm

If you seal them from the inside, the water will still be leaking into the wood from the outside... Best to turn the boat over and take a look at the keel, then go and have a stiff drink before telling us what you have found...
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Ed
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Re: Firefly centrecase leaks...

Post by Ed » Tue May 19, 2009 4:58 pm

Yes, I am with Rupert on this one.

You have to really have a good poke around, especially from the outside - up into the case.

I have found that the damage is often worse than you think....or it looks and it can get quite bad 'before' it starts leaking.

If you just dry it out and often this is much harder than it looks (in other words it remains damp inside a long time after you think it is dry from external examination), then you simply end up gluing together two bits of rotten wood and this may work stop the leak for a short while, but actually speeds up the rate of damage out of sight.

The big question is "how long has it been leaking?" If it has just started....and it was caused simply by breaking one of the joints between hull/hog/case, then you may be lucky....but first:

have a really good dig around with knife and awl. If you can find any soft wood - dig it out and carry on digging till you get to good wood. When do you stop? easy - if it comes out easily - remove it. If it is hard-work to cut - leave it. If you can only find a crack, try pulling a hack-saw blade down it. You have to remove both any soft wood and also as much of the old glue as you can.

This 'can' be depressing work. The last time I did it on my Firefly, I started with a couple of small holes/crack caused by trailer bouncing off keel onto edge of hull/keel joint. In a couple of hours I had 4 holes and two I could push my hand up to the knuckles in.

This is still easier and better than trying to glue rotten wood, which just doesn't very well.

OK....there are ways you can try to stabilise rotten wood with epoxy/wood hardener/G4.....but honestly it is easier and works better if you do the job properly. If you have to....we can explain how, but honestly the best recommendation is to first find the extent of the damage.

cheers

eib
Ed Bremner
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PeterV
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Re: Firefly centrecase leaks...

Post by PeterV » Tue May 19, 2009 8:06 pm

Agree with the above. I spent ages trying to fix the centreboard leak on my Mercury. When I took the case out and the keel off the outside I found the leak was between the hog and the floor. It had spread so far by then that the hog was rotten from the forward bulkhead all the way to the transom, despite looking fine from inside the boat. So the rule is, always fix a leak on the side the water's coming from!
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Rupert
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Re: Firefly centrecase leaks...

Post by Rupert » Tue May 19, 2009 9:17 pm

I should have added that if you want to keep the boat going for a while without taking her off the water, bath sealent works pretty well, and will peel off when you have a gap in the sailing schedule. Of course, the longer you leave it, the worse it gets...
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Re: Firefly centrecase leaks...

Post by ACB » Sat May 23, 2009 9:03 am

This is F3000. She is off the water and F3163 is on it. All nice and dry. "last job" after replacing decks and bouyancy tanks... will get a photo.

Somebody - quite possibly the same body who screwed into the delaminating side decks using rawlplugs and who renewed the bilge stringers with steel screws has had a great time with glass tape and epoxy at the after end of the case, It looks OK from the outside...famous last words...

F 3163 "Aquarius",
IC K229 nameless for the time being
I14 K377 "Mercury" - long term rebuild project

ACB
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Re: Firefly centrecase leaks...

Post by ACB » Thu May 28, 2009 7:01 pm

You lot were quite right!

F 3163 "Aquarius",
IC K229 nameless for the time being
I14 K377 "Mercury" - long term rebuild project

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Ed
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Re: Firefly centrecase leaks...

Post by Ed » Fri May 29, 2009 9:23 am

We can claim no 'intelligence'

only 'experience'

how bad is it?

Photos?

eib

PS carbon arrived yesterday, will pack up this w/end so send address
Ed Bremner
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Re: Firefly centrecase leaks...

Post by Ancient Geek » Fri May 29, 2009 11:43 am

Sadly you will not be the first person to have steel screws rather than, brass, bronze or stainless steel, many racing dinghies in the 1960's built by "Household Name" builders had steel screws that were used to hold whilst glue set and were then "plugged2 over and a certain well known Ocean Racer built at Cowes, when wrecked the broken salvaged hull showed that the same was true of bigger boats too.
If cost is an issue use steel screws by all means but take the blighters out when the glue/epoxy has set, you can fill the hole with spare glue/epoxy, save weight and problems for your succesors.
Simples.

ACB
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Re: Firefly centrecase leaks...

Post by ACB » Tue Jun 02, 2009 7:07 am

Pictures:

Image

F 3163 "Aquarius",
IC K229 nameless for the time being
I14 K377 "Mercury" - long term rebuild project

ACB
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Re: Firefly centrecase leaks...

Post by ACB » Tue Jun 02, 2009 7:11 am

The worst affected area - a strip of something like bath sealant came out of the hole between planking and hog and there is a soft patch about the size of a 50p coin (which is bound to get bigger...)

Image

From below - the Y piece at the aft end of the slot is visible

Image

F 3163 "Aquarius",
IC K229 nameless for the time being
I14 K377 "Mercury" - long term rebuild project

ACB
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Re: Firefly centrecase leaks...

Post by ACB » Thu Jul 30, 2009 8:43 am

I now have two regular shaped holes each side of the hog just aft of the centreboard case (which does not seem to have been affected at all).

Before going further, I would very much like to know how the centreline is constructed at this point - I am assuming that the veneers are laid up over the hog, and then planed flat and the outer keel glued and screwed in place.

If so, it will be best to remove the outer keel before re-veneering.

If on the other hand the veneers are laid into a rabbet, it would be best to leave well alone and just slide the veneers into the rabbet.

Guidance most gratefully appreciated!

F 3163 "Aquarius",
IC K229 nameless for the time being
I14 K377 "Mercury" - long term rebuild project

Rupert
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Re: Firefly centrecase leaks...

Post by Rupert » Thu Jul 30, 2009 8:53 am

The keel, I'm pretty sure, was put on after. Reverse engineering can be tricky, so taking the keel off is certainly the most straightforward (if not quickest) way of doing things. If you are lucky, you can get it off in one piece...though I doubt you'll get the screws undone...
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Ed
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Re: Firefly centrecase leaks...

Post by Ed » Thu Jul 30, 2009 9:44 am

How big are those holes?

if only small - under palm-of-hand sized, I don't think it would be worth trying to go to all the effort of removing the keel.

I will have to think about this a bit....or find some photos....but I am pretty sure the keel is smaller than the hog...

so you have enough area to work to and for glue to grab to by veneering up to and on to the hog and flush up to the outer keel.

I don't think I have ever removed any keel (unless it was damaged) to replace veneer.

For me the golden rule is......remove anything that is rotten.....leave anything that it solid and build around or into the gaps.

So if the veneer is rotten, where it goes under the keel....remove it....but if not - leave it. If you have a gap left, push the veneer up into it....if not, then there will be enough hog for glue to bind to. Remember Epoxy is much stronger than the old aerolite used.

hope this helps.

do send more photos

cheers

eib
Ed Bremner
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Jollyboat J3
Firefly F2942
IC GBR314 ex S51 - 1970 Slurp
MR 638 - Please come and take it away
Phelps Scull
Bathurst Whiff - looking for someone to love it

ACB
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Re: Firefly centrecase leaks...

Post by ACB » Thu Jul 30, 2009 10:33 am

Thanks; holes are sub-hand-sized.

Absolutely no chance with the screws, of course.

Ed is correct; the hog is wider than the keel.

More photos tomorrow. Delay was due to wanting to get her really, really dry.

The puzzle is working from two sides at once - I think that if I leave the keel in place I should do the outer (fore and aft) veneer first and use small wedges in the rebate to force it against the keel, then work from the inside. The fear is getting lumps of epoxy setting in the wrong place inside the rebate.

Robbins sent me (and I kid you not!) an 8 x 4 sheet of Agba veneer sandwiched between sheets of ply!

F 3163 "Aquarius",
IC K229 nameless for the time being
I14 K377 "Mercury" - long term rebuild project

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