Read TJD's comment carefully re
lightning strikes. A large nearby
catamaran on which much
money had been spent took a mast
head lightning strike. The carbon fiber mast was severely damaged where metal tangs etc. exited. The lightning hit a
VHF antenna and the mast may now be a total write off.
I have seen lightning strikes on alloy masts and beside the usual instrument losses etc. the masts invariably survive or can be easily repaired.
Alloy has extremely low
electrical resistance and thus minimal heat generated at large
current flow areas. Carbon fiber has "medium " resistance leading to extreme temperatures at high
current flow areas - although it is a bit more complicated than this. The carbon fiber damage seen on the local mast was mainly where
wiring and metal fittings exited. The carbon fiber damage was most extensive around load bearing spots such as spreaders and the base. Cheerful eh?
Also, it seems that the damage on the cat to ancillary
electrical components was greater than expected. Starter motors, alternators, air conditioners,
washing machine etc. as well as
electric winches. Everything electrical. A local electrician observed that with an alloy mast connected to the earthing system there would have probably have been less damage to ancillaries.
If weight saving is your main issue, try the relatively more cost effective process of replacing SS
rigging with Dynex etc. This material can be readily stored and is very user friendly.
If a mast is mechanically damaged, I would rather have to deal with aluminium than high tech carbon fiber.
The cost of the carbon mast referred to above cost more than most of the complete cruising sailing craft in our marina. It is seriously very, very expensive and you could
cruise for years on the cost savings of using standard well understood aluminium.
TJD's comment about
insurance says it all. What was not mentioned was the increase in insurance premiums required to cover carbon fiber mast replacement. I would certainly check this out. Lightning may be excluded.
However, if you are loaded with
money and want to win races go ahead. But consult the real experts as you could be simply wasting money. Fiber masts are usually designed and engineered from the ground up to suit the particular vessel requirements. Generally you can't obtain a uniform extrusion as they have wound in extra (engineer determined) reinforcing at load points and some fiber orientation/quantity may be variable as well. A mast is important but there are many other considerations in
racing.
If cruising and you need to add something onto the mast, alloy allows riveting, thread taping, welding, sleaving etc. Alloy is also malleable.( i.e. a "dent" may lead to minimal strength loss). Not so for carbon fiber.
Another issue to consider is that many
epoxy materials don't like UV. I would be asking the providers about certified data on the longevity of the material. It is also usually left black which means that in the tropics it gets cooked, which seems a negative as well. It has lower thermal conductivity as well possibly leading to different thermal stressing issues. e.g. baking hot on one sunlit side, cold on the other.
Finally, can anyone list any current production cruising sailing boats that use carbon fiber masts?