Repair advice for carbon rear foil wing damage

Wind Slither · Since 04 Mar 2005 2611 Posts The 503 METAL

I feel like I saw a thread on this but can't find it...

Yesterday I noticed the tip of my Axis 370 rear foil wing took a hit somehow. It's flexing a bit at the crack you can see and if I tried I think I could break the tip off with my fingers.

How best to approach this? Could i just layer it with some sun cure epoxy and sand it down. or does it need some sort of vacuum clamp?

TIA,
-WS

Windian · Since 28 Apr 2008 899 Posts Newport, OR NEWPORT OG

Check out this video:

https://www.youtube.com/watch?v=KU2qph2vG9Y

I have heard that aircraft mechanics use this method for repairing chips in props. Lives depend on props being balanced and not falling apart during flights. Foilers can also use it to repair their water toys.

ldhr · Since 21 Jul 2009 1487 Posts Hood River XTreme Poster

What Hein says.....

Hein · Since 08 Mar 2005 1314 Posts Possessed

Stop by the hobby shop and get some thin CA glue. Apply it and it will wick into the crack and fuse everything back together. Then a light sand leaving the sanding dust in any remaining cracks or voids; apply some more CA. A little more sanding and CA until it's all smooth. You can apply a little CA to that tip and dip it into some baking powder to build it up. Then sand to desired shape. When all done spray with a light coat of clear acrylic. Wet sand with 400-600 and respray & repeat until its smooth and clean. The repair won't be quite a strong as new but should be good unless you have another impact. And will only take a few 10-30 minutes since the CA glue cures pretty much instantly.

All the best,
Hein

CA is CynoAcrylate aka Superglue. You want the super thin high quality type available at the hobby shop.

Wind Slither · Since 04 Mar 2005 2611 Posts The 503 METAL

Thanks you guys...I am leaning toward the super glue / baking soda approach. I have some off this loctite liquid super glue...would it be good enough? Nowhere on it does it list ingredients or explicitly mention CynoAcrylate but maybe that's redundant to the term "super glue"?

Home Depot doesn't have the Loctite 495 that was referenced in Windian's vid.

I can try some hobby shops today if this isn't high quality or thin enough.

eric · Since 13 Jan 2006 1853 Posts XTreme Poster

I have used the super glue/baking soda method many times.--with supermarket Crazy Glue and it works well. But, Hein is very knowledgeable about materials and a highly skilled engineer, so if he is suggesting a higher grade glue I would be inclined to follow his lead. When I need to do another repair I am going to try his glue recommendation out.

Eric

Wind Slither · Since 04 Mar 2005 2611 Posts The 503 METAL

Yep, had the same thought. Went into Tammy's Hobbies today and scored some "super-thin" cyanoacrylate ~$6.

Will report back...

Wind Slither · Since 04 Mar 2005 2611 Posts The 503 METAL

This seemed to go really well. The cynoacylate seemed to trickle right down into the cracks and saturate the carbon fiber. The baking soda make it dry fast and leaves it whitish to guide your sanding.

Next time I will be a little less liberal with the glue so save the sanding. I also just used the sandpaper on hand so I went 400 --> 1000 -->2000. I haven't got to the acrylic yet and I think it already looks pretty good.