How to attach hardware to carbon fibre spars

Posted by michel.capel (michel.capel@…>)

Hi all,

I know thsi question has been answered in the past, but in those
days I didn’t pay attention to them because I had aluminum masts on
my catketch. The new boat has CF masts. I have the rare
combination - at least for Freedoms - of wishbones and single ply
sail on a track. The previous owners used the wishbones as
conventional booms; almost horizontal. I want to go back to the
original setup with the wishbones sloping downwards and rigging them
like a Wyliecat. For that I need to install several strong padeyes
on the spars; e.g. for the wishbone hangers, the throat ajusters and
the tack reef points. I know 3 ways to attach padeyes, could you
help me decide the best way:

  1. use stainless, monel or aluminum rivets;
  2. thread the holes and use stainless machine screws;
  3. just screw in selftapping screws in the holes.

Does it help to epoxy the screws?
How tight can the holes be without risk of splintering the CF?
Do I have to ask the sparmaker to epoxy on carbon pads under the
padeyes to get more meat to drill and screw in?

Thanks!
Michel

Posted by lance_ryley (lance_ryley@…>)

Michel,
when I went to the Freedom yard last year, they said the best thing
to do was to drill and tap the holes, then fill them with epoxy when
you screwed into the mast. Judging from past experience with this
question, however, everyone has a different opinion on this subject.
Another possibility which you didn’t mention is to use compression
bands around the mast to hold hardware in place. the bands pass
under the sail track, so there’s no interference there. I’ve seen
that mounting system used for radars and steaming lights on a couple
of the Nonsuch’s and the hybrid nonsuch cat ketch at my marina, and
it looks pretty good.

I’d stay away from self-tapping screws. I imagine that would
probably tear up the fiber more than any other method.

Lance

— In freedomyachts2003@yahoogroups.com, “michel.capel”
<michel.capel@…> wrote:

Hi all,

I know thsi question has been answered in the past, but in those
days I didn’t pay attention to them because I had aluminum masts
on
my catketch. The new boat has CF masts. I have the rare
combination - at least for Freedoms - of wishbones and single ply
sail on a track. The previous owners used the wishbones as
conventional booms; almost horizontal. I want to go back to the
original setup with the wishbones sloping downwards and rigging
them
like a Wyliecat. For that I need to install several strong
padeyes
on the spars; e.g. for the wishbone hangers, the throat ajusters
and
the tack reef points. I know 3 ways to attach padeyes, could you
help me decide the best way:

  1. use stainless, monel or aluminum rivets;
  2. thread the holes and use stainless machine screws;
  3. just screw in selftapping screws in the holes.

Does it help to epoxy the screws?
How tight can the holes be without risk of splintering the CF?
Do I have to ask the sparmaker to epoxy on carbon pads under the
padeyes to get more meat to drill and screw in?

Thanks!
Michel

Posted by Lorman, Alvin J. (ajlorman@…>)

Michel:

Most Freedom mast tracks are attached with rivets, which is a pretty good indication of what Freedom thought worked well. When I wanted to attach some small hardware to my mast, I consulted with a tech service guy at GMT composites and he said that rivets, appropriately spaced, would not materially weaken the mast.

Al Lorman
F30 Ab Initio

-----Original Message-----From: freedomyachts2003@yahoogroups.com [mailto:freedomyachts2003@yahoogroups.com] On Behalf Of michel.capelSent: Friday, February 24, 2006 5:12 AMTo: freedomyachts2003@yahoogroups.comSubject: [freedomyachts2003] How to attach hardware to carbon fibre sparsHi all,I know thsi question has been answered in the past, but in those days I didn’t pay attention to them because I had aluminum masts on my catketch. The new boat has CF masts. I have the rare combination - at least for Freedoms - of wishbones and single ply sail on a track. The previous owners used the wishbones as conventional booms; almost horizontal. I want to go back to the original setup with the wishbones sloping downwards and rigging them like a Wyliecat. For that I need to install several strong padeyes on the spars; e.g. for the wishbone hangers, the throat ajusters and the tack reef points. I know 3 ways to attach padeyes, could you help me decide the best way:1) use stainless, monel or aluminum rivets;2) thread the holes and use stainless machine screws;3) just screw in selftapping screws in the holes.Does it help to epoxy the screws?How tight can the holes be without risk of splintering the CF?Do I have to ask the sparmaker to epoxy on carbon pads under the padeyes to get more meat to drill and screw in?Thanks!Michel
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Posted by Frank Minelli (myslo@…>)
Michel, glad to know there is somebody else aorund that sails withthe wishbone and the single ply sail on track ! When I discarded my wrap arounds, I epoxied a glass strip, 5 ply, 12 oz weave, to the spar (sanding the paint off first) and then screwed the track to that with sheet metal screws. I inserted epoxy into the screw holes, then drove the screws home. Same with the pad eyes on the stick for suspending the boom. This has worked now since 2001, for about 5000 miles of open ocean cruising. I would be interested to learn more about the variation of outhaul used on the Wylie cat. Do you have the details?“michel.capel” <michel.capel@…> wrote: Hi all,I know thsi question has been answered in the past, but in those days I didn’t pay attention to them because I had aluminum masts on my catketch. The new boat has CF masts. I have the rare combination - at least for Freedoms - of wishbones and single ply sail on a track. The previous owners used the wishbones as conventional booms; almost horizontal. I want to go back to the original setup with the wishbones sloping downwards and rigging them like a Wyliecat. For that I need to install several strong padeyes on the spars; e.g. for the wishbone hangers, the throat ajusters and the tack reef points. I know 3 ways to attach padeyes, could you help me decide the best way:1) use stainless, monel or aluminum rivets;2) thread the holes and use stainless machine screws;3) just screw in selftapping screws in the holes.Does
it help to epoxy the screws?How tight can the holes be without risk of splintering the CF?Do I have to ask the sparmaker to epoxy on carbon pads under the padeyes to get more meat to drill and screw in?Thanks!Michel
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Posted by Jack George (chamela7@…>)
Hi Frank, Ive been in Oceanside for about a week now and waiting for your shipping instructions for the wishbone stuff. I will be here for about 4 more weeks, Ok let me know . Jack George Frank Minelli <myslo@…> wrote: Michel, glad to know there is somebody else aorund that sails withthe wishbone and the single ply sail on track ! When I discarded my wrap arounds, I epoxied a glass strip, 5 ply, 12 oz weave, to the spar (sanding the paint off first) and then screwed the track to that with sheet metal screws. I inserted epoxy into the screw holes, then drove the screws home. Same with the pad eyes on the stick for suspending the boom. This has worked now since 2001, for about 5000 miles of open ocean cruising. I would be interested to learn more about the variation of outhaul used on the Wylie cat. Do you have the details?“michel.capel” <michel.capel@…> wrote: Hi all,I know thsi question has been answered in the past, but in those days I didn’t pay attention to them because I had aluminum masts on my catketch. The new boat has CF masts. I have the rare combination - at least for Freedoms - of wishbones and single ply sail on a track. The previous owners used the wishbones as conventional booms; almost horizontal. I want to go back to the original setup with the wishbones sloping downwards and rigging them like a Wyliecat. For
that I need to install several strong padeyes on the spars; e.g. for the wishbone hangers, the throat ajusters and the tack reef points. I know 3 ways to attach padeyes, could you help me decide the best way:1) use stainless, monel or aluminum rivets;2) thread the holes and use stainless machine screws;3) just screw in selftapping screws in the holes.Does it help to epoxy the screws?How tight can the holes be without risk of splintering the CF?Do I have to ask the sparmaker to epoxy on carbon pads under the padeyes to get more meat to drill and screw in?Thanks!Michel Yahoo! Mail Bring photos to life! New PhotoMail makes sharing a breeze.
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