Cored hull???

[klos]

How can you tell if a hull is cored, I admit Idon't know much about this topic.
If I am understanding this correctly there are hulls manufactured whith a balsa, foam, etc. core?
does that mean that there is an inner and outer fiberglass hull? All the boats I have restored are glass all the way through. I
Is there an advantage to this or is this just another way of building a cheaper boat?
Also when I'm looking for project boats is there an easy way to tell or do you just have to start drilling?

Thanks

 

[tommays]

Re: Cored hull???

If its done "right" its really costly and gives a light stiff hull

If its done wrong its a nightmare that can NOT really be repiared very easy

I think you find it the most on High performance sailboats like this

The core is END GRAIN balsa blocks and each piece is pre-sealed in expoy before it is installed to stop any water migration

Tommays

 

[Bondo]

Re: Cored hull???

The Bigger Bilgeliners,+ Searays are all Cored Hulls,........

It Works,......

But as Tommays says,......... When things go Wrong,........ It's Really Wrong........

 

[ondarvr]

Re: Cored hull???

Normally you can see the foam or balsa blocks in the unpainted areas of the bilge, sometimes you can see the pattern even if it is painted.

What brand, size and model of boat is it? somebody here may know if it is.

 

[tommays]

Re: Cored hull???

This a core from my boat when i installed a Knot Meter fitting

Its 3/4" thick about 1/8 glass 3/8 balsa and 1/4 of glass to finish the sandwich

A 24' hull with a 8'9" beam only weights 2200# and has as close to ZERO flex as i have ever seen in a boat


Searay does everything they can to do cores REALLY WRONG and give balsa a bad name :devil:

Tommays

 

[Old Salt Oz]

Re: Cored hull???

How can you tell if a hull is cored,

Tap it, it has a softer more hollow sound than solid glass.

does that mean that there is an inner and outer fiberglass hull?

Yes, but it also applies to the deck and some internal fittings.


Is there an advantage to this or is this.

Yes, stiffer boat for less weight, also better sound and thermal insulation.

when I'm looking for project boats is there an easy way to tell or do you just have to start drilling?

Tapping should be enough.

Note: Avoid any boat that has a composite / sandwich hull below the water line, the risks are high that repairs will be very costly and time consuming.

Hope this helps

Avagoodweekend......

 

[klos]

Re: Cored hull???

Thanks for the replies, that clears things up a bit. The boats that I'm interested in are the older power boats. Formula, Donzi, Baja, etc. Is it a pretty safe bet that these none of these were built with cored hulls?

 

[Solittle]

Re: Cored hull???

If you get any water in the core you have rot that it is almost impossible to fix.

 

[threedeesmax]

Re: Cored hull???

Some runabouts and small cruisers of the late 1950s and early 1960s had balsa cores. My 1961 Red Fish Shark is built that way, with balsa pieces that measure about 2 1/2 inches by 6 inches, individually shaped to fit the floor's contour.

 

[threedeesmax]

Re: Cored hull???

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