size on unstayed carbon fiber mast for tri-star 42 ?

[vuilbaard]

Hello.

having a hell of a time figuring out how big a diameter and wall thickness i need for an unstayed carbon fiber main mast holding a junk sail (of 700 sq ft M/L at 42 feet on the mast and 18feet at the battens) for my newly acquired, never floated, started building in mid 1980's Ed Horstman Tri-Star 42 that i am finishing out.

it came with a self furling main (kenyon brand 55 feet long) that i am selling as i am old and like junk rigs for easy of single handing and no damn clawing of wet cold fabric to reef.

So how large a diameter tube? all the sources i used to go to are now 404...

any ideas on where to start?

i am going to use an aluminum tabernacle and industrial carbon fiber tube (no taper needed) at 20 feet and join with internal ferrules for strength.

thanks for any assistance....

[Redreuben]

Go to Harryproa website and contact Rob Denney, he works with unstayed carbon masts with a company that builds masts for his boats. He is very helpful and should be willing to do the engineering.
http://etamax.com.au


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[nuvaslacker]

Sounds a really interesting project. Good fortune in your endeavours!

Would love to see some photos. There are quite a few "traditional" trimaran fans on CF.

[atoll]

you might try looking at the spec's on some of the freedom yachts masts

https://en.wikipedia.org/wiki/Freedom_Yachts

[Sand crab]

Eric Sponberg is a proponent of free standing masts. He is retired but might be able to help. https://www.ericwsponberg.com/

BTW My tri is in the same yard as yours.

[foufou]

Ted Van Dusen at Composite engineering in Masachusets is the guy to ask

[Puget Dan]

We have a 1997 38' Tri Star and love it here in Seattle. When we got it 5 years ago I contacted I contacted Ed Hortsman in Big Fork Mt. and he was really helpful dealing with Ama rudder issues. Ed is gruff but will talk you ear off. Have not spoken to him in 4 years and he must be late 80"s now but worth a try. His number was 406-837-0768.