minor deck core repair help

[firedreamer]

OK, the pole davit opening in the sundeck roof that is pictured is 3in. in diam. the top and bottom surfaces look to be a fiber impregnated fiberglass. Very solid ! The top is about 1/4 in. and the bottom is about 1/2 in. thick, they both ( top & Bottom) are sound, not wet or damaged in any way that I can tell. The wood inside between them is bad out to about 3-4 inches. It was pretty soft and wet. I dug that out and was told from a all around structural strength stand point I could just fill the void with a spray-foam and call it good. I was wondering what you all thought? is there a spray-foam out there that would work, I see the local online marine supply dealers have "Evercoat" but I was hoping I could find some kind of maybe an epoxy type or something that would be strong and waterproof. your suggestions are much appreciated. I will need to cut out the material, whatever it is to put the pole back down through it. 2.jpg3.jpg4.jpg2.jpg3.jpg4.jpg

[Boatsb]

OK, the pole davit opening in the sundeck roof that is pictured is 3in. in diam. the top and bottom surfaces look to be a fiber impregnated fiberglass. Very solid ! The top is about 1/4 in. and the bottom is about 1/2 in. thick, they both ( top & Bottom) are sound, not wet or damaged in any way that I can tell. The wood inside between them is bad out to about 3-4 inches. It was pretty soft and wet. I dug that out and was told from a all around structural strength stand point I could just fill the void with a spray-foam and call it good. I was wondering what you all thought? is there a spray-foam out there that would work, I see the local online marine supply dealers have "Evercoat" but I was hoping I could find some kind of maybe an epoxy type or something that would be strong and waterproof. your suggestions are much appreciated. I will need to cut out the material, whatever it is to put the pole back down through it. Attachment 14234Attachment 14235Attachment 14236Attachment 14234Attachment 14235Attachment 14236

what bayliner engineer recommended spray foam?

the strength of that area is dependent on rebuilding the laminate and bonds. Balsa core is pretty strong but other materials like plywood can be stronger. Do it right and do it once.

[jim rosenthal]

Spray foam is a bad idea and I think whoever gave you that advice doesn't understand what this area does on your boat. Actually I can't think of ANY area of a boat that should be fixed using material like that.

The decayed area needs to be absolutely dry; which usually take a while. Putting a fan on it for a few days may help. It looks like this is a high-stress area, so you should rebuild it using marine plywood, or possibly Coosa board- one of their heavy laminates which has several layers of glass cloth in it.

This is not a simple repair. I am very much in favor of our doing our own work when possible. But this might be one of the instances in which you should get a professional to do the repair, and you can do the cleanup afterwards.

In order to get a structurally sound repair that will hold up, you will have to restore the coring out to a distance of seven or eight inches around the opening, at least, I would think. Then you have to compress the two outside layers to get them to bond to the replacement coring, using epoxy or vinylester resin to glue them all together solidly. I suppose the way to do that is a lot of support from underneath and a lot of weight on top, using release fabric so you don't glue the support to the underneath panel, nor the weight to the top panel. I'd also suggest dry-fitting everything and working out how you are going to compress everything well in advance. This seems to me to be a complex job.

[carolinacoast]

I am going through this same issue right now. What Scott said. Any damaged area that is accessible has to be opened up, removed, dried out and the core replaced. Then, re-bed everything up there to make sure there is no future water intrusion.

There is likely to be a surveyor involved when you sell her and the spray foam concept probably will not work out very well. My $0.02.

[bobk]

There are higher density foams that can be used. This link will take you to density of almost 40lb/cu ft. That would be adequate for reinforcement. Dig out the bad wood, dry the area and clean it. You could prime with a fluid epoxy mix and then pack in the foamable epoxy. Trim back and paint the end area with thickened epoxy and you are good to go. This is what Hatteras should have done with these penetrations to begin with. My sundeck top was fixed with this method seven years ago. Now you will bolt the upper and lower flanges to solid, almost non-compressible structure.

http://www.corecomposites.com/compos...foaming-epoxy/

Bobk

[SeaEric]

Pettit makes epoxy repair products called "Splash Zone". It comes in a tube that mixes epoxy and hardener in the tip, or it comes in cans like putty that you mix together and apply by hand. With the amount of space you have with the open hole to access the area, you can probably make a nice repair without opening up the deck. I believe that the Splash Zone stuff does not require absolute dry conditions to cure.

[Capt Paul]

Spray foam is a bad idea and I think whoever gave you that advice doesn't understand what this area does on your boat. Actually I can't think of ANY area of a boat that should be fixed using material like that.

The decayed area needs to be absolutely dry; which usually take a while. Putting a fan on it for a few days may help. It looks like this is a high-stress area, so you should rebuild it using marine plywood, or possibly Coosa board- one of their heavy laminates which has several layers of glass cloth in it.

This is not a simple repair. I am very much in favor of our doing our own work when possible. But this might be one of the instances in which you should get a professional to do the repair, and you can do the cleanup afterwards.

In order to get a structurally sound repair that will hold up, you will have to restore the coring out to a distance of seven or eight inches around the opening, at least, I would think. Then you have to compress the two outside layers to get them to bond to the replacement coring, using epoxy or vinylester resin to glue them all together solidly. I suppose the way to do that is a lot of support from underneath and a lot of weight on top, using release fabric so you don't glue the support to the underneath panel, nor the weight to the top panel. I'd also suggest dry-fitting everything and working out how you are going to compress everything well in advance. This seems to me to be a complex job.

I would think that you could just clamp it together instead of the support and weight concept if you go with that approach.

[Colwyn D]

As said you have reasonable access. If you are sure the area is localised and you have removed all the damaged core then dry out whats left, may take days even with a fan heater. Brush inside the repair area with neat epoxy, coat everything. Mask off underneath and start filling with thickened epoxy, 1/4" max at a time or it will overheat. The final layer I like to inject the epoxy with a fillable caulking cartridge and tube and start at the back of the repair, this stops air locks at the back of the void and the pressure of the epoxy keeps it in contact with the upper skin as it finds it's way out. Re drill your holes. West system epoxy and their 407 filler work well.
Expanding foam, no way. Other option as mentioned is to remove a skin and rebuild the area. This would leave no doubt as to the extent of the rot and be a 100% repair.

[jim rosenthal]

As far as moisture goes, it's not an issue of curing so much as an issue of bonding to the inside of the two fiberglass layers. I don't think a repair will bond to them if they are still damp, although I like those Pettit products, too.

And if you're going to use plywood or Coosa, you'll have to cut either the top or bottom out to get it in there, won't you? How will the replacement core get inside without removing enough FRP to lay the pieces in there?

If there's a foam that will work- be strong enough, water resistant, and bond to the top and bottom layers, great. There are a lot of products I don't know.

Let us know what you decide and post photos, please. You are not the last Hatteras yachts owner who will confront this problem, I betcha.

[rrrestorer]

Why not jam a bunch of resin soaked fiberglass matting in there. You would get a strong and waterproof repair, and you wouldn't have to cut up the deck. Jam the mat right trough the hole you have now, clean up the inside of the existing glass and rough it up as much as you can, it'll stick to both sides and hold them together. Seams like the simplest way to fix, unless I'm missing something.