Core materials

[Jeffrey]

I will soon be building single and twin engine outboard tunnels hulls. The boat in question is 21 feet long 7.5 feet wide and I want it to weigh around 1200#'s. I will be subcontracting out the construction and I am looking for recommendations on the Hull, deck, transom and bulk head coring materials. All of the boats in question will be powered to run 100 to 125mph. Maybe even glass recommendations as well

Thanks
Jeff

[Henry Nicholson]

Jeffrey,

The massive slamming loads that a boat like this would recieve means that you need a core with an immense amount of toughness and elongation, Core-Cell is a market leader for these type of applications and is commonly used in powerboats and racing yachts where other PVC foams tend to break down or suffer from Core shear. Plywood or a 200kg foam would be required in the transom to support the engines, though make sure ply is well sealed before use to stop any moisture ingress.

Core cell can be used with epoxy or polyester and can be 'thermoformed' to hull s which is handy

Hope thiis is useful


Henry Nicholson
Henry

[Keith Burnham]

I am look for a material that they us for a transom that has on wood in it compoust.

[Buckle]

Think outside the circle.

A sandwich concept is great. But if you are aiming for the higher end of the performance scale. Move towards carbon for your skins. The increased stiffness would help transfer the loads into your bulkhead. Thus stressing your core to a lesser degree.

Long-grain and endgrain balsa has high shear properities.

Buckle

[Herman]

For boats running 100-125 mph, I would certainly advise to look for a technician with at least the experience in that business. Or at least unveil some general drawings, so people can make some more specific recommendations.

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To be more correct about Core-Cell:

This is not a PVC foam, but a SAN foam. It characteristics hold middle between cross linked (more brittle) and lineair (more ductile) PVC foams.
Nowadays there are more types of Core-Cell, with higher compression strength, higher stiffness, and temperature. Please check out their website and take a look at the datasheets for more info.

You can also contact SP North America, and see what they recommend.