Topic: Crackle in decks?

Mine basically sounded out as one big void.....  After pulling the deck  apart from the inside (gettin the old plywood out) I'd say that maybe 80% of the surface area of the foredeck wasn't bonded to the upper skin.  The edges were bonded, but in the centre it was not and never was bonded.  Not enough resin?  Probably not.  I'd say that the decking was installed after upper skin cured.  Probably even after they popped the deck from the mold they put the plywood in, and then covered with 1 layer of chopped strand.  So, if you're trying to bond a flat peice of plywood to the forward deck which is sagging in the middle a bit (don't forget, the deck is still inverted at this point), then she aint gonna stick.  Anyways, the wood is now all out from the chainplates forward, and I'll replace it with smaller sections and stagger them like a hardwood floor (so to have no continuous gap running fore and aft...  stiffer...)

Re: Crackle in decks?

Any reason why you are not using end-grain balsa and vacuum bagging?

Re: Crackle in decks?

time, money, simplicity, the area in which I have to work, the fact that if balsa ever does get wet it turns to mush, etc etc

Re: Crackle in decks?

If it's done correctly, it doesn't turn to mush.

Re: Crackle in decks?

As long as it doesn't get wet.  Which is why I'm at this point anyways.  As long as I own the boat, the core will stay dry. 
The big factors are simplicity, and simplicity.  It'll be better than any other Contessa that has original coring in the decks...

Re: Crackle in decks?

Anyone else have a foredeck that makes crackly noises when walked upon?  I suspect a dry layup (insufficient resin) but am avoiding drilling holes to find out.

Re: Crackle in decks?

It seems everything I have read has been about deck repair from below. Why not cut from the top?
Cut down thru the f/g to the core, remove the core, replace the core and glass and epoxy from the top not from below and above your head in very ight places. Not to mention the cutting out of the interior. Cover the repaired deck with one of the several non-sid deck materials that are glued on (see Practical Sailor). I have not done this but in theory it seems a much better approach.

Re: Crackle in decks?

For most boats this would be the way to go - seeing as you're going to paint the deck anyways.  The construction of the Contessa side and fore decks is a bit different - the top skin of glass is about 1/4" thick ++ in some places, then the plywood, then the liner on the inside.  The liner is only 2 layers of CSM and then gelcoat.  This isn't enough to support the works if you remove the top skin and decking.  Think of the entire cabintop like a 1/4" thick eggshell and not so much like a sandwich construction.  The plywood underneath is really just bonded up to the top layer of the sandwich, and the bottom layer is just the liner to cover everything up.

As far as delamination in the cabintop decks go - I've just finished squeezing in about a half-gallon of west system in a dozen or so voids that I tapped out.  She's rock solid now.

Re: Crackle in decks?

I have just brought a Contessa that has been out of the water for over 4 years – although not covered and is in need of TLC. The inside cabin liner has delaminated itself just behind the mast support, as far as I can see the rest looks okay. How can I check for more delaminating/failure of the plywood and what’s the best repair for the delaminating if that’s all it turns out to be?
Also when I walk on the cabin roof area there is some ‘bounce’ in the fiberglass, I would expect this as normal (I’m 220lbs), although the guy at the fiberglass repair shop says there should be no deflection, and a structural repair is required, which is true?

Re: Crackle in decks?

agrobbi,

I actually remove the fiberglass on the deck, my deck was bouncy and the fiberglass guy told me to redo the laminate. Well!!!, it was not a good idea, the laminate at the deck is (from inside to outside) a small fiberglass liner, a sheet of plywood and 1/4 to 3/8 inch of fiberglass.

The problem was not the infiltration of water but the outside fiberglass was not laminate (glue) to the plywood. A costy repair for nothing. My advise is remove all the hardwares at the deck, look if the core is good, the water can only come there, repack the hardwares with sikaflex 295 or 3m 4200 and leave the deck like it is, if you can't tolerate a bit of flexing if i was you, i will drill somes holes around the flex area deck and fill them with epoxy.

Marc

Contessa 26 #158
Sun Wave
Montreal QC

Re: Crackle in decks?

Yes, we are going to cut into our side decks as well to repair from the top, as if one has to redo some non-skid, may as well cut along the inside of nonskid and clean out the rotten plywood underneath.   But you are right, the boldness is actually making the first cut!  The boat has been dried out for several months, so it won't be so messy, but we can still see the damaged plywood...also makes you realize that it is simply...water getting in that wrecks things...I mean, if the items weren't screwed into the deck incorrectly the first time, grrrr!!!  And...you can see that it is simple to rectify...prevent water from getting in there in the first place, as smh said: do it right...  The deck will flex a bit with 220 lbs on it, the key is the crackling sound....if you hear it, there are multiple layers crackling...and from water or just weak layup, you will want to fix it.   And being brave and cutting the deck is part of it, heh heh........

“You get a boat for only one reason, because you want one.  If you’re worried about being practical, forget boats.”

Re: Crackle in decks?

i would (did) work from the inside.  the top skin is the meat of the deck - once you cut the top skin out theres nothing really holding the deck together as the bottom "skin" isnt really a skin, just cosmetic.

Re: Crackle in decks?

In another month or so Tim Lackey will be cutting into my decks, from the top, to ":fix" the crackling. I mentioned the comments on this sight as approaching the problem  from above vs from below. We'll see what happens.
This is his first Contessa refit.

Re: Crackle in decks?

i would have a closer look at this bfore cutting the top out.  i have some pictures that i can pass along or post up once i find them on my computer.

Re: Crackle in decks?

I totally agree with Stefan on this one -- although it is easier to work from above, the outer skin (or the top layer of the sandwich) is perhaps 80-90% of what makes the structure on our boats.  Cut through the deck, remove the core and I would think it very unlikely the boat would go back together again neatly.  I would be very concerned about deformation of that remaining thin skin before the repair can be completed. 

I discovered soggy plywood in the poop deck on my boat a few seasons past.  My strategy was to remove the offending fittings (in my case the vents for the engine) and stick an electric space heater in the lazarette for a few days.  It was probably not the safest way to dry the deck but the low setting provided sufficient heat to dry out the wood.  The wood itself was not rotten, but frost had done its work such that it had been weakened and was no longer bonded in the 'sandwich' of the deck.  I chose to leave the weakened wood in place and did my best to saturate the wood with epoxy before adding filler and restoring the sandwich of the deck.  Two things made me confident of the repair -- one was the 1/4"+ of glass above the wood, and the second was the short span.  Engineers look at deck structures like beams with the span in this case being the shorter dimension.  That is, the poop deck is about 8"x 48" so as a beam the deck structure needs only to support my weight over an area that is less than the length of my shoe.  Structurally, I just did not see the need to replace the weakened wood.

Last season I replaced the deck fills on my boat and again found a spot of damp wood in the deck.  The wood was exposed to the weather, BUT was largely dry because the Taylor people had not installed the wood properly.  The inside layer of glass was a singly ply of 'glass that passed over the wood and was then bonded to the upper deck surface at either end.  For some reason they left two of the four edges of the wooden piece exposed (picture laying a piece of paper over your keyboard and taping only two of the four edges to your desk).  This was beneficial for me because the exposed edges allowed the escape of any water that entered the wood.  For those contemplating side deck repairs, look closely -- the wood may not be as bad as you think.

For my crackly foredeck I intend to do the same repair that Stefan did with his cabin-top:  drill a few holes and pump the area full of epoxy to saturate the dry laminates and to re-bond the plywood in the foredeck.

However IF I KNEW that I had bad wood in the area, I would first dry it out and then try injecting a product like Git Rot into the wood to consolidate it, followed by epoxy to rebond the wood core to the surrounding fibreglass.  Dry, decayed wood LOVES soaking up epoxy.  The deck would be heavier because of the weight of the resin, but I expect that I would use even more resin in any other version of the repair.  And the time/effort savings is obvious.

If anyone does decide to tackle a deck repair from above, please let us all know how it goes.

Re: Crackle in decks?

Christofer,

When you said :
"Cut through the deck, remove the core and I would think it very unlikely the boat would go back together again neatly.  I would be very concerned about deformation of that remaining thin skin before the repair can be completed."

I agree with you that if you don't pay attention when you redo the fiberglass work you will end with a deformation. I did the recore by removing the top layer of fiberglass, i (we) just finish to laminate the fiberglass. If someone want to do it(I discourage them, i think the epoxy filling can do the job) the key to succes is to take your time. My sequence was: Remove the top layer, remove the wood, grind the remaining of wood, put at most two layers of mat, wait until it's dry, THEN in my case i put a layer of corecel glue with polyester resin, wait until dry, then 2 layers of mat, 1 layer of roving, 1 layer of mat, 1 layer of mat, 1 layer of roving, 2 layers of mat. All 8 layers was put 1 after 1 after one in the same time, we worked ( me and my helper) fast. We rolled only when all layers was put on the boat. I can confirm that it's a doable job BUT I did it only because i hired a specialist, my helper is a professionnal and i'm the amateur.

Even if you recore the deck with the epoxy way, take your time, don't go too fast because you will for sure deform the liner inside the boat, the skin is so thin, it's unbelievable.

I have a lot of pictures of the work, i will try to take the time to send it on the pictures gallery

So the key to succes is patience, take your time.

Marc

Contessa 26 #158
Sun Wave
Montreal QC

Re: Crackle in decks?

When I drilled holes and filled the voids on Branwyn, I had epoxy leak in the cabin from the side of the liner.
It would be an easier cleanup if you have someone in the cabin while you inject the epoxy,
Just a thought.

Re: Crackle in decks?

Mine leaked out the liner as well. Try some masking tape between the hull and deck liner to seal the gap and prevent the drizzles.