Carbon Fibre Masts

[freedom44]

Can anyone suggest how one checks the integrity and future lifespan of a carbon mast?
I think it was the Hugo Boss boat whoses carbon mast just shattered. How does one prevent/anticipate this, or is it because of the stress and strains such a boat suffers and a normal cruising boat hopefully will not.
Any contacts in the trade to talk to would be most welcome.
Thanks

 

[AngusMcDoon]

Big ones? Talk to Marstrom...

Marstrom Composites

Ickle ones? Talk to the manufacturer/importer of Dragonflies. They all come with CF masts as standard.

There are not many normal cruising boats with CF masts. Dragonflies have used them for a while, and they don't cause problems.

 

[William_H]

The standard test for integrity of any fibre reinforced plastic and especially CF is known as the coin test. tap the mast all over with a large coin looking (listening) for a hollow or dead sound indicating delamination.
Other wise just check for surface condition indicative of UV damage to epoxy. If it is not epoxy even that is not a problem. olewill

 

[Lakesailor]

Why would you use a CF mast. Does it reduce weight aloft, or is it to do with strength, or maintaining sail shape?
Someone on the lake has just fitted out a Bennie with one for racing. I was a bit perplexed as to the cost/benefit.

 

[[2068]]

Don't know about sailing yachts, but they've been CF on Windsurf masts for years.

Major advantage is you can bend them quite a lot and they'll spring back to the original shape, so the mast can maintain the sail in a very particular shape if you rig it right. Also light, stiff as you want, very easy to make as a "round" mast. Not sure how easy to make as a more complex shape with spaces for rigging etc.

When they break, it's pretty sudden, and normally due to overload as the sticky stuff holding the layers of fibres together comes apart, and the whole lot just goes crunch.

dv.

 

[AngusMcDoon]

The main reason for using a CF mast is weight reduction aloft. A CF mast weighs about one third of an equivalent alloy mast. 1kg at the top of the mast requires 5-10kg at the bottom of the keel to counterbalance it. Synthetic fibre rigging can reduce this further.

Another reason for their use is that they can be moulded into a greater variety of shapes than an alloy mast can be, and strength at particular areas can be better controlled by increasing laminate thickness and fibre orientation. An example of this is the foil section masts used by many performance multis.

They don't have particular reliability problems. If they break, they go suddenly, but then so do pretty much all mast types when they fail. Cruising boats can be made with long lasting reliable CF masts, for example Farrier/Corsairs and Dragonflies. The downside is cost.

 

[freedom44]

Thanks for your input.
To answer lake sailor, my boat has 2 un stayed CF masts, which are remarkable. they are designed to bend 1 mtr at the top if necessary!
There is nothing wrong with them to my knowledge; its just that I would like to understand if there is any method to check their integretity during their lifespan. I suspect that they are hugely over specked compared to modern ones, as they were built 20 yrs ago in CF technology infancy.
They at least have a lifetime guarantee ( for the first owner!!!)