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Freedom 40 cat ketch: Aluminum mast taper fairing

Posted: Sun Nov 20, 2016 6:12 pm
by VeloFellow
Freedom 40 #7 is undegoing an extensive refit. Getting ready to repaint the aluminum mast. Anyone know the fairing compound used where lower straight well joined the upper tapered section?

Re: Freedom 40 cat ketch: Aluminum mast taper fairing

Posted: Mon Nov 21, 2016 1:02 pm
by bad
We did our masts 4 years ago. Hull number 21. We have a two piece longitudinal fiberglass shell, about 4 ft long, and it was cracking circumferentially at the top and bottom and along the longitudinal seams. We removed all loose fairing, taped the longitudinal seams with 2", 10oz fiberglass tape, faired everything smooth and painted. We used West System epoxy and fairing powders. The lower circumferential joint is cracking again.

Given the vintage of the boat the original sleeve and fairing are polyester resin based. You may, after chipping and grind all loose material off, consider using the 3M glass reinforced Bondo to fair with. Easy to work and you can sand after 20 min. Once all faired, I would take the masts down to bare metal above and below the fiberglass sleeve, even creating a 1/16" relief on the lower section for about 4". There is a large gap between the two metal sections and any material you are removing on the outer mast is not structual. I would use a fiberglass braided sleeve ( like http://www.sollercomposites.com/composi ... fiberglass) to bridge the entire fiberglass fairing and transitioning into the two mast sections where you have bare metal. You should use an epoxy resin system since it will bond best to the metal. If you saturate the braided sleeve with sufficient resin and then use peel ply on top, the final finish should be ready for further fairing with an epoxy or vinylester fairing compound near the ends, and the rest is good to prime and paint.

Best of luck, and whatever you do, post pictures!

Erik

Re: Freedom 40 cat ketch: Aluminum mast taper fairing

Posted: Sat Nov 26, 2016 4:48 am
by VeloFellow
Thanks erik,

Steve was curious about what material was used as the original fairing compound really is in incredible shape for 40 years old.

Re: Freedom 40 cat ketch: Aluminum mast taper fairing

Posted: Sat Nov 26, 2016 11:55 am
by bad
That is indeed what you wrote... :oops:
Our's was reddish brown. The original Bondo is similar in color.

I still think a sleeve or fiberglass tape would be the best way to keep it from re-cracking.

Does the boat still have the wrap around sails?

Erik

Re: Freedom 40 cat ketch: Aluminum mast taper fairing

Posted: Sat Nov 26, 2016 9:11 pm
by cberdie
We've tried both bondo and epoxy over our 20 years of ownership. Both cracked as soon as we encountered reefing situations. Remember the mast is supposed to bend. As soon as it does, the crack will open up. I've wondered if 3m 5200 would work as it has some stretch in it. Both our masts have had that crack in them for 20 years, less a couple of months, it doesn't seem to harm them.
Carl

Re: Freedom 40 cat ketch: Aluminum mast taper fairing

Posted: Thu Dec 01, 2016 6:17 am
by VeloFellow
Thanks, Carl.

It is interesting to see the longevity of these mast with the number of lifetime cycles of tip whip theye have been through both loaded and unloaded. The Bondo makes sense. Why add the sleeve when it appears cracing extends through that when used?