1979 19 ft Sea Ox rebuild

Questions about boat repairs with our resins and fiberglass: hull patches, transoms and stringers, foam, rot etc.
Mr Pamlico
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Re: 1979 19 ft Sea Ox rebuild

Post by Mr Pamlico »

So could I laminate the coosa before or after glueing in to add the strength needed? That would put me over 3.5 inches thick where the jack plate and engine would mount

fallguy1000
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Re: 1979 19 ft Sea Ox rebuild

Post by fallguy1000 »

Mr Pamlico wrote: Sat Apr 03, 2021 11:29 am So could I laminate the coosa before or after glueing in to add the strength needed? That would put me over 3.5 inches thick where the jack plate and engine would mount
Well, I don't think 5x1700 is enough. I don't think the coosa is a great idea. I, personally would add 5 layers of glass inside and then knee.

But I can't really understand how you are planning to get cables to the thing even.

If you post over on boatdesign.net, someone might tell you a laminate schedule for no well. I'd say that 170 ounces a side is probably close.

For the additional 5 layers, I'd recommend laying them 10",8",6",4",2" over the top and same on the sides.
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Mr Pamlico
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Re: 1979 19 ft Sea Ox rebuild

Post by Mr Pamlico »

That sounds like a good plan. I will add those 5 layers as suggested and knee. I was planning on building two small corner boxes that follow the contour of the cap and was going to run my rigging from the back right corner. Just a diagonal piece of coosa across the corner. These would also be where the bilge pumps on either side of the tunnel pump out on either side. After I get the knees finished I will decided for sure. I could box in between the knees and run my rigging up from that and have the bilge pumps pump through the back of the transom maybe and those small corner boxes would not be necessary. That would also give a small box in effect without taking up a lot of room in the back. I just would like the back as open as possible

fallguy1000
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Re: 1979 19 ft Sea Ox rebuild

Post by fallguy1000 »

The top at 5 layers is a little weak here, but it would be a good telltale. If the top gets stress cracked, you'll know its too light.
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Mr Pamlico
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Re: 1979 19 ft Sea Ox rebuild

Post by Mr Pamlico »

What is everyone’s opinions on flotation foam? My original thought was that I would have drains from the tank back and would seal everything else off completely. That way if I took on a lot of water it would not be able to fill the bottom of the boat completely. Or if I had something puncture the hull it would just fill up that one compartment. I’ve rethought that bc if water ever does get in one of those compartments for any reason it won’t be able to drain out. So I think I’m going to put drains in each bulk head to allow them to drain to the back of the boat. I would like to have some sort of flotation just in case something happens the boat won’t go down completely, especially in the winter time. My worry is the foam soaking up water over time, as I plan on this boat sticking around for a while even when I upgrade one day. I’ve read that if the two part closed cell foam isn’t mixed just right it will soak up water. Any other options? Or just leave it out and don’t worry with it

Fuzz
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Re: 1979 19 ft Sea Ox rebuild

Post by Fuzz »

If it were me I would put limber holes in all the bulkheads so water could drain to the stern. I would run drain pipes from between the stringers so I could drain each section between the stringers to a bilge sump. I would make the drain pipes so they could be plugged. This way any water can be drained but if you hole one section it will not flood the other ones.
I like fairly wide gunwales and would try to build them so I could get enough floatation there to hold the boat up and keep it upright if swamped. Part of my thinking is this keeps the foam well above the water line so the debate over absorbing water should be a moot point.

fallguy1000
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Re: 1979 19 ft Sea Ox rebuild

Post by fallguy1000 »

I'd foam it for safety.

Build a set of limbers. The trick is always making a path for water. A sacrificial piece of plastic or fiberglass along the bottom spot glued with nylon could work. Plastic laid over the top of that makes a simple path. You just need to make sure the foam doesn't seal off the limbers!

Fuzz' drain pipes idea with holes in the pipe and plastic above can also work, but if you have a vee, a flat thing above it can work and unsealed edges can allow seep.

A dry bilge can be built with a piece of lexan over it. The lexan will fog or condense water if the boat gets wet and so you'd know. Seal the lexan down with butyl tape, add a bilge pump if you want. It can be under the lexan.

My thoughts.

My boat is designed with watertight boxes; the tops are sealed with pvc caps. Last summer, I did not seal the caps with teflon tape and had quite a bit of water enter a few of them. We had like 8" of rain in on month. I spent quite a bit of time dewatering. Now this summer, I plan to run the shopvac in reverse in each chamber to dry them. No system is perfect. I have 17 sealed chambers! Probably gonna need to do annual inspections of them before freezeup. If you have a single inspection spot; that'd be better.
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Mr Pamlico
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Re: 1979 19 ft Sea Ox rebuild

Post by Mr Pamlico »

I really like the idea of running drains that I can plug from each compartment to the bilge. I have not thought about that. I think I will go with that idea as well as the pour in foam. I am going to use the same cap that is on the boat and I’m not sure if there would be enough room to add enough flotation under there. Hopefully I can build the compartments water tight and keep them plugged so there will be no chance of water getting to the foam unless something is leaking or something bad happens. I will leave the tank and the back center compartment without foam and have everything drain to that back compartment where the bilge pumps and thru hull will be. I’m still trying to wrap my head around how to pour the 2 part foam in and not block the drains. I think I understand what you are saying fallguy about about putting something angled in the corner allowing a drain path to the limber hole. But if water somehow got on top of the foam or say came in to the compartment on the other side would it be able to reach the drain? I might be over thinking this and it could be one of those it is what it is scenarios. I just want to make sure I prevent as many future problems before the floor goes down

Fuzz
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Re: 1979 19 ft Sea Ox rebuild

Post by Fuzz »

Take your pipe with holes in it and fill it with sand. After pouring the foam you can wash the sand out. If needed a small drain snake will clean the sand out.

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Re: 1979 19 ft Sea Ox rebuild

Post by OneWayTraffic »

I'm going through the same thought process with my build. Two part foam doesn't seem to flow much before it starts to rise. You could build a dam in the centre of a compartment from plastic and cardboard, pour some foam into it, and then remove the dam. I managed to get some higher density polyurethane block foam offcuts from an industrial supplier at a good price. I am thinking of using these glued to the hull at the bottom to form a path for water and for the higher resistance to vibration. Then some pour foam on top, to lock it all in.

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