DN NA Class

Guests & Members Post & Read => Building, Maintaining and Repairing => Topic started by: Bob Gray on December 08, 2009, 02:36:08 PM



Title: Applying Carbon fiber
Post by: Bob Gray on December 08, 2009, 02:36:08 PM
  I needed to apply an 8 foot strip of carbon to my mast. I remembered an article Ken Smith wrote about using superglue to apply carbon to an aluminum steering rod and decided to try it. I left a narrow strip of masking tape on each end of carbon so I'd have something to hang on to. I then applied a generous amount of superglue to the mast, laid the carbon over the glue and sprayed it with insta-set. I stretched out the carbon and did the same thing on the other end. I ended up with the straightest tow of carbon fiber I've ever seen and I did it by myself. I got the glue at a hobby shop since they carry thicker superglue then you'd get at a hardware store. They also carry Insta-set which is what it sounds like, a product that instantly set up superglue. Thanks Ken, it worked great.       Bob


Title: Re: Applying Carbon fiber
Post by: DN5135 on January 05, 2010, 09:54:14 PM
Bob, does the super glue just tack the carbon in place or are you using it in place of epoxy.


Title: Re: Applying Carbon fiber
Post by: Bob Gray on January 06, 2010, 07:38:32 AM
  It kind of replaces the epoxy. I put a tab of masking tape on each end of the carbon strip (for grip), applied about an inch of super glue, let it set, stretched the carbon and glued the other end. After all is said and done, I cut the tabs off and did apply epoxy over the glued parts for insurance. I've been sailing the mast and it's held up just fine.       
                        Bob


Title: Re: Applying Carbon fiber
Post by: Geoff Sobering on January 06, 2010, 11:05:29 AM
Bob, are you saying that the only adhesive is a 1/2" band of superglue and epoxy at either end of the carbon-fiber tows? (i.e. the center 8 foot portion of the tows are unbonded?)


Title: Re: Applying Carbon fiber
Post by: Bob Gray on January 06, 2010, 02:30:21 PM
 Not what I meant. The whole carbon strip has to be saturated with epoxy, I just meant that you only need some epoxy over the glue at the very ends . Sorry about that. I also vacuum bag the mast to get rid of excess epoxy ( which can cause failure in carbon strip). If you can't bag the mast, the next best thing would be to tightly wrap it in the cellophane packaging film ( that stretchy stuff).
       
       I was told by an expert in carbon structures that excess epoxy will eventually breakup some and the shards can cut the individual carbon strands leading to failure.    Bob


Title: Re: Applying Carbon fiber
Post by: Bob Rast DN1313 on January 06, 2010, 03:00:43 PM
If applying additional reinforcement make sure you sand the mast as the proset epoxy is not the same formulation as Regular wests. I like using wet sand paper and then final wipe with acetone or similar to have a good clean surface and adhesion.
Poor mans vacuum bag  shrink wrap
A tip for shrink wrapping is to wet out glass or carbon and cover with a piece of  poly or visqeen before wrapping. wrap lightly at first then additional wrap pulling harder on shrink wrap.
If you don't  use some poly as a cover the shrink wrap gets  embedded  in the glue.
rasty
DN1313