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Old 21-03-2013, 23:32   #16
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Re: Construction methods??

Interestingly, on another forum, one of the balsa bashers when presented with evidence of a piece of balsa cored Duflex which had been kept in an inter tidal area for several years, with only minimal water penetration and NO rot, commented that it wasn't a valid test because seawater PRESERVES balsa!

So I'd have thought that would make it perfect for use below the waterline!
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Old 22-03-2013, 02:12   #17
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Re: Construction methods??

None of the models Kita asked about are of Duflex construction so 44c's comments are not valid.
Duflex is a panel that has either foam or balsa laminated between thin epoxy glass skins. None of these boats are constructed using this or remotely similar methods.
Yes, the most common form of timber rot found in boats, is fungal "dry rot". A bit of a misnomer as it is favoured by fresh water and inhibited by high concentrations of salt, which dehydrates the fungal hyphae. Old sailers knew this and sluiced decks with salt water to slow rot and swell timbers to stop leaks. But their boats STILL rotted. This is historical fact.
A balsa core below waterline soaked in seawater would probably rot much more slowly than if was soaked in fresh. Just because it is below the waterline is no guarantee that water in the core will be salt!
I would prefer neither. Solid glass below waterline and dry core above, preferably high density foam.
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Old 22-03-2013, 02:36   #18
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Re: Construction methods??

Comments about balsa cored fibreglass aren't relevant to a discussion about balsa cored fibreglass? OK, if you say so sir.
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Old 22-03-2013, 03:52   #19
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Re: Construction methods??

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Originally Posted by 44'cruisingcat View Post
Comments about balsa cored fibreglass aren't relevant to a discussion about balsa cored fibreglass? OK, if you say so sir.
When ever the topic of rot in balsa cores comes up in this forum, as it has many times, you are at pains to distinguish between "any old balsa" core and your favourite "Duflex". You obviously have a vested interest as you own a boat constructed of that material. If you wish to believe that Duflex doesn't rot, as you assert, then fine, but these three models are not Duflex boats.

That being so, as I have stated, the balsa cores in Lagoons and Leopards are not particularly prone to rot. Except for water ingress due to poor post-production fitting of screws and through-hull fittings, the thick laminate seems to protect the core.
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Old 22-03-2013, 04:21   #20
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Re: Construction methods??

"Balsa basher" I like that!

Here's a real Balsa Basher at work:

Polycore Independent Impact Tests - YouTube
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Old 22-03-2013, 05:03   #21
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Re: Construction methods??

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That being so, as I have stated, the balsa cores in Lagoons and Leopards are not particularly prone to rot. Except for water ingress due to poor post-production fitting of screws and through-hull fittings, the thick laminate seems to protect the core.
I have seen dozens (at least) of boats with balsa rot due to production flaws. On a recent survey of a Lagoon I found an area of the hull skin that was 3mm thick ! A few hours of flexing and it won't take long for water to get through that skin.

PS. There is no such thing as "dry rot" in wood according to US mil.specs.
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Old 22-03-2013, 06:42   #22
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Re: Construction methods??

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"Balsa basher" I like that!

Here's a real Balsa Basher at work:
That doesn't look like balsa to me?
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Old 22-03-2013, 06:48   #23
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Re: Construction methods??

Just like anchors, and blisters, everybody has an opinion on Balsa. Here's mine

Balsa Core = Compost
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Old 22-03-2013, 14:12   #24
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Re: Construction methods??

Quote:
Originally Posted by tuskie View Post
"Balsa basher" I like that!

Here's a real Balsa Basher at work:

Polycore Independent Impact Tests - YouTube
Yeah, build a boat of rubber. That'll work.
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Old 26-03-2013, 08:23   #25
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Question Re: Construction methods??

Quote:
Originally Posted by boatpoker View Post
I have seen dozens (at least) of boats with balsa rot due to production flaws. On a recent survey of a Lagoon I found an area of the hull skin that was 3mm thick ! A few hours of flexing and it won't take long for water to get through that skin.

PS. There is no such thing as "dry rot" in wood according to US mil.specs.
Ok I am reading all this & am just loving all the info, I need to ask something here, It seems as though you are doing survey`s. How do you tell the thickness of hull skin without cutting open the hull?
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Old 26-03-2013, 09:05   #26
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Re: Construction methods??

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Ok I am reading all this & am just loving all the info, I need to ask something here, It seems as though you are doing survey`s. How do you tell the thickness of hull skin without cutting open the hull?

you don't (unless you are doing audio gauging) If you look at the two photos posted you'll see I inserted a dental probe with a hook in it, then applied a piece of black tape against the hull and then measured the the distance between the hook and the tape (3mm). I punched the hole with my finger.
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Old 26-03-2013, 10:14   #27
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Re: Construction methods??

I have so many questions, How do I find someone to do a survey that knows what he is doing? Seems like someone can just say, hey everyone I am a surveyer!!! How would I know otherwise? I am making a LIFE CHANGING move here & know alot about the mec. side of things but not much about hulls, I have lived on a lake all my life & worked as a mec. / welder/machinest forever & am not that scared of nuts & bolts & have done some glass work. I once made a glass fenderwell for a lifted 4X4 & it looked & worked great & I found that I kinda have a knack for it but I HATE that stuff, point is I can fix things but if I am going to move my entire life to a catamaran I don`t want to fix the hull, so a good survey is going to be VERY important for me, even more so because I have alot of time with power boats & next to nothing with sailboats & here I am selling EVERYTHING to go sailing. The only thing on my bucket list is a circumnavigation. I am 53, Now I don`t plan on going off unschooled & have been researching things for a long time & plan on a year or two close to home (south FL & the Bahamas) but once I get it sorted out,why stay in FL? Been here all my life & want to go walkabout, or sailabout I should say. So I guess after reading the Bumfuzzle log It hit me, man if they can do it, I KNOW I can!!!! I also know I will catch some flak about being a rookie & all but,,, there are fokes out there that don`t know half of what I do doing it & it beats sitting home..
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Old 26-03-2013, 10:44   #28
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Re: Construction methods??

[QUOTE=Kita;1195090]I have so many questions, How do I find someone to do a survey that knows what he is doing? Seems like someone can just say, hey everyone I am a surveyer!!! How would I know otherwise? / QUOTE]

My own highly biased opinion on How To Choose A Surveyor
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