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Gman13

Crack in bilge 2008 chapparal 224 Sunesta

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The hardest thing to control during fabrication is the application thickness of the gelcoat. When you see "stress cracks" in the hull exterior, it has little to do with a structural failure. The substrate flexes and gives with the pounding a boat experiences. The Gelcoat can follow the deflection profile pretty well, and typically survives. Where cracks appear it is as a result of areas where the super hard, brittle gelcoat material has accumulated in mold areas that allow puddling. My feeling on your failure is a similar situation where the spray in bilge liner final finish coating puddled at the 90 degree corner between the interior hard chine and hull. Nothing structural happening there, but I would grid out all the loose, flaked material, and re-coat the area with vinyl ester resin to prevent water infiltration into the substrate. Be sure to expose the freshly ground repair area to a heat lamp ensuring that the underlayment is totally dry before applying the repair material. West Marine "West Systems" has the products you will need.  W

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Yup, open it up and examine the fiberglass below. Hard to say if that is cosmetic or structural crack without knowing what's happening under. Was the boat stored outside in below freezing temperatures? In any case, this needs to be examined, dried, repaired as needed, and made to be watertight.

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On ‎6‎/‎3‎/‎2018 at 11:18 AM, Wingnut said:

The hardest thing to control during fabrication is the application thickness of the gelcoat. When you see "stress cracks" in the hull exterior, it has little to do with a structural failure. The substrate flexes and gives with the pounding a boat experiences. The Gelcoat can follow the deflection profile pretty well, and typically survives. Where cracks appear it is as a result of areas where the super hard, brittle gelcoat material has accumulated in mold areas that allow puddling. My feeling on your failure is a similar situation where the spray in bilge liner final finish coating puddled at the 90 degree corner between the interior hard chine and hull. Nothing structural happening there, but I would grid out all the loose, flaked material, and re-coat the area with vinyl ester resin to prevent water infiltration into the substrate. Be sure to expose the freshly ground repair area to a heat lamp ensuring that the underlayment is totally dry before applying the repair material. West Marine "West Systems" has the products you will need.  W

My wife and I are really hoping it is just cosmetic, but the crumby thing is its location. it is smack dab under the engine, which makes it very very difficult for me to investigate. We had our marina's fiberglass guy try and look at it but said we'd need the engine pulled to do so. I believe our boat, 2008 Sunesta has encapsulated wood stringers, and that makes me think they are more resilient to moisture. If I can chip away the flakes what should I look for as far as structural damage? I think it would be obvious signs of cracks...

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11 hours ago, Gman13 said:

My wife and I are really hoping it is just cosmetic, but the crumby thing is its location. it is smack dab under the engine, which makes it very very difficult for me to investigate. We had our marina's fiberglass guy try and look at it but said we'd need the engine pulled to do so. I believe our boat, 2008 Sunesta has encapsulated wood stringers, and that makes me think they are more resilient to moisture. If I can chip away the flakes what should I look for as far as structural damage? I think it would be obvious signs of cracks...

I bought a USB camera on line for 20 bucks, and it comes with software which allows me to view and even record video in color. It has a 15' cord, is moisture proof, and smaller in diameter than a pencil. It has a fixed focal length of around 12", but they do have ones that can be focused from the lap top keyboard. Can't tell you how many times I've used it. Oil leaks, engine combustion chamber inspection, and even within walls of a house. It has it's own internal light so you can push it into a black hole. Cell phone photo works too if your arm is long enough.

As far as the flakes go, think of it as thick, hard paint. If it flakes off clean, and the cracks you see go no deeper than the coating itself, the it's a coating failure. If the cracks are in the substrate and seem to emanate outward from there, then that is likely where they began. Impregnated wood stringers can be characterized as moisture resistant, not waterproof so if you discover that the cracks go deep, beyond the surface layer, you will need to grind until the cracks are gone to see what type repair you are looking at. Cant tell much from your photo, but I will say that surface cracks in the bilge coating are common and relatively harmless if addressed.  W

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On ‎6‎/‎13‎/‎2018 at 7:53 AM, Wingnut said:

I bought a USB camera on line for 20 bucks, and it comes with software which allows me to view and even record video in color. It has a 15' cord, is moisture proof, and smaller in diameter than a pencil. It has a fixed focal length of around 12", but they do have ones that can be focused from the lap top keyboard. Can't tell you how many times I've used it. Oil leaks, engine combustion chamber inspection, and even within walls of a house. It has it's own internal light so you can push it into a black hole. Cell phone photo works too if your arm is long enough.

As far as the flakes go, think of it as thick, hard paint. If it flakes off clean, and the cracks you see go no deeper than the coating itself, the it's a coating failure. If the cracks are in the substrate and seem to emanate outward from there, then that is likely where they began. Impregnated wood stringers can be characterized as moisture resistant, not waterproof so if you discover that the cracks go deep, beyond the surface layer, you will need to grind until the cracks are gone to see what type repair you are looking at. Cant tell much from your photo, but I will say that surface cracks in the bilge coating are common and relatively harmless if addressed.  W

That's a great idea, I was thinking about looking into a small camera like that. I think that should be our first step, before making a mountain out of a mole hill. Thanks!  -- ofc hoping for the best but expecting the worse. We're not looking to take the path of least resistance and a major repair if needed is not off the table. Arming yourself with as much information as possible before handing it off to a repair shop is essential nowadays...

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On ‎6‎/‎3‎/‎2018 at 2:01 PM, Richard W said:

Yup, open it up and examine the fiberglass below. Hard to say if that is cosmetic or structural crack without knowing what's happening under. Was the boat stored outside in below freezing temperatures? In any case, this needs to be examined, dried, repaired as needed, and made to be watertight.

Hello,

It is stored in a four wall building (Rack Storage), and we make it a point to have the bilge dry before winterizing it. I'm going to follow WingNuts advice with the camera -- if okay would sealing it with 4200 be acceptable?

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If there was water ingress into the fiberglass or wood inside, the bilge could have appear dry but the water contained inside the structure still could freeze and expand ... something to keep in mind while you are inspecting the cracked area.

Clean it up, let it dry, and seal it with the original material, namely gelcoat. The sealant like 3M 4200 or 5200 will make it work but will not make it right. Beside being a patch job, the sealant will obscure the visual clues if the problem continues to develop.

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10 hours ago, Richard W said:

If there was water ingress into the fiberglass or wood inside, the bilge could have appear dry but the water contained inside the structure still could freeze and expand ... something to keep in mind while you are inspecting the cracked area.

Clean it up, let it dry, and seal it with the original material, namely gelcoat. The sealant like 3M 4200 or 5200 will make it work but will not make it right. Beside being a patch job, the sealant will obscure the visual clues if the problem continues to develop.

Thanks for the reply, your information is helpful. We'll inspect it with the camera first, and if it looks okay we'll try and look into resealing. This whole thing is a huge learning experience for us so we really appreciate the feedback.  If we have any doubts well have it professionally looked at. Any tips for removing the loose gel coat in the area? We'd ideally like to remove a nice section around the visual crack, but lack any ideas on how to do that...

 

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If this is just a stress crack and there is nothing else going on under the gelcoat, you would remove any loose gelcoat bits, even the rough edges and sand the edges a bit so the crack is easier to fill and the surface near it is easier to "paint" with gelcoat. Often Dremel is your friend while preparing and shaping the cracks. Just use it on edges to the depth of the crack, do not go any deeper.

If there is more going on ... let's wait and see what you will find out.

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5 hours ago, Richard W said:

If this is just a stress crack and there is nothing else going on under the gelcoat, you would remove any loose gelcoat bits, even the rough edges and sand the edges a bit so the crack is easier to fill and the surface near it is easier to "paint" with gelcoat. Often Dremel is your friend while preparing and shaping the cracks. Just use it on edges to the depth of the crack, do not go any deeper.

If there is more going on ... let's wait and see what you will find out.

Thanks for the tips; we ordered the camera that WingNut had suggested and we'll post some pics of the progress.

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On 6/15/2018 at 1:50 AM, Richard W said:

If this is just a stress crack and there is nothing else going on under the gelcoat, you would remove any loose gelcoat bits, even the rough edges and sand the edges a bit so the crack is easier to fill and the surface near it is easier to "paint" with gelcoat. Often Dremel is your friend while preparing and shaping the cracks. Just use it on edges to the depth of the crack, do not go any deeper.

If there is more going on ... let's wait and see what you will find out.

Hi, we did some digging around and took some samples while we lightly chilled the edges. 

The one half is the upper surface but what is the pink stuff? And how serious does it look if that is what’s protecting the stringer?

081F7B5C-93D3-4AE6-A7E4-D7A4A5C99F8E.jpeg

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On 6/3/2018 at 11:18 AM, Wingnut said:

The hardest thing to control during fabrication is the application thickness of the gelcoat. When you see "stress cracks" in the hull exterior, it has little to do with a structural failure. The substrate flexes and gives with the pounding a boat experiences. The Gelcoat can follow the deflection profile pretty well, and typically survives. Where cracks appear it is as a result of areas where the super hard, brittle gelcoat material has accumulated in mold areas that allow puddling. My feeling on your failure is a similar situation where the spray in bilge liner final finish coating puddled at the 90 degree corner between the interior hard chine and hull. Nothing structural happening there, but I would grid out all the loose, flaked material, and re-coat the area with vinyl ester resin to prevent water infiltration into the substrate. Be sure to expose the freshly ground repair area to a heat lamp ensuring that the underlayment is totally dry before applying the repair material. West Marine "West Systems" has the products you will need.  W

We removed some of the loose material, and found some pink stuff on the underside of the gel coat? 

How serious is it from the initial looks? We thinking it s pretty serious. IF we were to wait until the end of the season the get it fixed what is the best way to protect the area from water? 

6DE69143-15E3-4FD8-A75D-247D11FD4ED6.jpeg

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While those are some good sized chunks, I don't think that is too critical. I think the thing to be concerned with is the water intrusion. Hopefully you will be able to dry everything out and re-gelcoat or resin everything up and be good to go.

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The concern is never what chips off, but what is left behind. The loss of the barrier coat exposes the substrate to water intrusion. The remaining surface must be ground in order to see how deep the issue goes, and also to prep the surface giving it teeth so the new material will bite. Dry out the ground area and clean with acetone, followed by several coats of either polyester or epoxy resin. Poly is stronger, and epoxy is more flexible but both can be applied full thickness without fear of cracking. If the void is deep, a layer of fiberglass cloth will help fill the void and add structure. A final gel coat application can be rolled on for esthetics, or the repaired area can simply be painted with a good epoxy as your resin repair has re-established watertight integrity. Looks like a small area and minor repair so I would net wait.  W

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2 hours ago, Wingnut said:

The concern is never what chips off, but what is left behind. The loss of the barrier coat exposes the substrate to water intrusion. The remaining surface must be ground in order to see how deep the issue goes, and also to prep the surface giving it teeth so the new material will bite. Dry out the ground area and clean with acetone, followed by several coats of either polyester or epoxy resin. Poly is stronger, and epoxy is more flexible but both can be applied full thickness without fear of cracking. If the void is deep, a layer of fiberglass cloth will help fill the void and add structure. A final gel coat application can be rolled on for esthetics, or the repaired area can simply be painted with a good epoxy as your resin repair has re-established watertight integrity. Looks like a small area and minor repair so I would net wait.  W

I have never seen any test data showing poly resin to be stronger than epoxy resin. 

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Poly is stronger, and epoxy is more flexibl...

Feels like an unintended transpose ... should read ... Epoxy is stronger, and poly is more flexible ... at least that is my understanding.

@Gman13

The pink/orange stuff could be simply mold and grime but most likely some exposed fiberglass leaching. Just follow what Wingnut said, get all affected/weakened fiberglass out, if not too deep fill it in with poly resin, sand lightly, and paint with gelcoat to finish.

BTW, poly resin and gelcoat which is based on poly resin are compatible. The epoxy resin and gelcoat are not. Poly resin and gelcoat bond together chemically. Gelcoat on top of epoxy resin only adheres mechanically, similar to painting the metal, and does not create a strong bond. Some brands of epoxy resin are not suitable for gelcoat application no matter how well you prepare the surface.

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