Panga 20 Concerns

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newavacado
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Panga 20 Concerns

Post by newavacado » Thu May 03, 2018 1:17 pm

Hi all. Bought plans and ready to start on a Panga 20 but am a little concerned about durability. I've built a open Glen-L 19' in the past so I have some experience. It looks like the between the deck and keel are completely sealed compartments. To me, I was always taught this is a special invitation to collect water and rot. I know this is "sealed" with epoxy, but that is only water resistant not impervious. I assume the other designs are like this also? Any thoughts. I will be spend most of it life on a trailer so that helps. Thoughts?



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Re: Panga 20 Concerns

Post by narfi » Thu May 03, 2018 3:54 pm

Most of the boats here are filled with foam and sealed.
Sealing prevents water from getting in, If something terrible happens and water does get in, it has no place to go since the foam is already there.

Most of the boats here are self bailing, The sole is above the water line and the drains can be left open. This means no standing water when stored in the rain, etc.... so much less chance of water finding a way by your sealed sole.

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Re: Panga 20 Concerns

Post by Fuzz » Thu May 03, 2018 3:56 pm

First welcome to this bunch. You will find us to be a friendly bunch.
To foam or not is the big debate.
You need positive floatation in any boat under 20 foot. How you go about getting it is up to the builder.
The foam in WELL sealed compartments does this and adds a huge amount of stiffness at the same time. If you hole the hull you will still float and that is a good thing :D
You can limber hole every thing and not foam. No chance of trapped water but the boat can flood and maybe sink.
I will say there are a number of boats built the the foam they sell here that are getting old and have shown no problems.
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Re: Panga 20 Concerns

Post by seaslug » Thu May 03, 2018 10:16 pm

I may be wrong, but as far as I know epoxy is completely impervious to absorbing water, so you don't have to worry about water getting into the wood core if properly sealed, or water getting into a properly sealed and foam filled area below the waterline.

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pee wee
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Re: Panga 20 Concerns

Post by pee wee » Fri May 04, 2018 8:45 am

I like the foam filled and sealed compartments, but this discussion has come up before and one option talked about that is workable is to drain all the compartments to the rear and fit a plug in the final opening. You can pull that plug from time to time and check for water. If you were to completely seal a large compartment but not fill it with foam, it can expand like a balloon under a hot sun, in extreme cases causing something to crack.

The foam does a few things for you: it prevents a compartment from filling with water and possibly the boat from sinking in the case of a hull breach. It also provides support for the sole if it's trimmed off flush at the top. It will also makes the boat feel more solid and quiet.

Cons to the foam are few- it costs money, adds a little weight and it takes time and effort to install. For most designs here the recommendation is to fill enough compartments to assure the boat has positive upright flotation, and leave the rest without foam.
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Re: Panga 20 Concerns

Post by newavacado » Fri May 04, 2018 9:36 am

Ok thanks guys! Probably going the foam route. I was wondering about the air expansion too, so it looks like foam addresses that also. The boat will probably never spend more than a week in the water before going back on the trailer so I think it'll be OK.

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Steven
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Re: Panga 20 Concerns

Post by Steven » Fri May 04, 2018 6:02 pm

I accidentally drilled a hole in my sole when I was repositioning the batteries in the console. Air was expelled under pressure. Nothing extreme as I foamed under my entire sole. But it confirmed to me that those foamed, sealed compartments won't be taking on any water.

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Re: Panga 20 Concerns

Post by TomW1 » Fri May 04, 2018 6:47 pm

newavacado these boats will last you a life time properly built and maintained. There is a C19 built in the mid 90's that is still going strong. I have a Mirror dingy built by her and her dad in the late 1960's. The Mirror was one of the very first stitch and glue boats.

Just follow the build instructions and ask lots of questions. This system is a lot different than a Glen-L. But you will get an excellent boat. Some guys cover all the wood for extra strength, not really needed. Some do only bring the fiberglass up on the outside for protection, not a bad idea. But everything gets covered with epoxy and since we use marine mahogany will never rot.

Tom
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Re: Panga 20 Concerns

Post by jacquesmm » Tue May 15, 2018 11:22 am

More: the USCG accepts sealed compartments as buoyancy volume. This means they trust them to stay sealed.
For peace of mind, you can always install inspection plates.
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Re: Panga 20 Concerns

Post by TomTom » Wed May 16, 2018 2:14 am

Steven wrote:
Fri May 04, 2018 6:02 pm
I accidentally drilled a hole in my sole when I was repositioning the batteries in the console. Air was expelled under pressure. Nothing extreme as I foamed under my entire sole. But it confirmed to me that those foamed, sealed compartments won't be taking on any water.
Question for Jacques ... is there ever a concern that large sealed compartments can build up enough pressure differences with the air inside them from expansion due to heat (or changes in elevation when say towing the boat) that you can crack the joints...

I know epoxy is strong, but the pressure changes must be fairly large especially in places with high temperature variations... I think back to high school geography and "freeze-thaw fracture" and can't help but wonder whether a similar thing is happening in large sealed compartments on a boat...

Are there pressure valves for such applications? Or is this another good reason for sealing>

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