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Carbon Fiber Repair - Hydrotail

ghc19127

Oct 5, 08 20:28

Post #1 of 8 (261 views)

Carbon Fiber Repair - Hydrotail	Can't Post

Somehow I cracked my Hydrotail. The photos are below. Anyone have any thoughts on the best way to repair this?

My thought was epoxy. I'm just not sure exactly what brand would be best or if it would hold up. The spot where it cracked is a flex point.

I'm curious if I should try to squeeze something into the crack and clamp it or tape it or if I should break it clean then try to fit it together. I just doubt it will go back together.

Any thoughts are appreciated, including... "just buy a new one."

1406racer

Oct 5, 08 20:32

Post #2 of 8 (257 views)

Re: Carbon Fiber Repair - Hydrotail [ghc19127] [In reply to]	Can't Post

You cannot repair it by using epoxy. To get an effective structural repair you will need to add plys of carbon like a patch to rebuild the strength in that area. If you don't have access to carbon fiber and have not worked with it before you may be better off buying a new one.

Raptor

Oct 5, 08 21:45

Post #3 of 8 (239 views)

Re: Carbon Fiber Repair - Hydrotail [ghc19127] [In reply to]	Can't Post

You can go to a radio control model airplane hobby store (Hobby People) and get both 30 minute epoxy and some 6 oz fiberglas. The fiberglas should help it become rigid again. The hobby shop may have a carbon strip that you can also attach with epoxy. I would use at least 4 to 5 layers of fiberglas.

Make sure you use vinyl gloves when using epoxy, as you will eventually get an alergic reaction to it.

(This post was edited by Raptor on Oct 5, 08 22:02)

Andrew69

Oct 5, 08 22:26

Post #4 of 8 (221 views)

Re: Carbon Fiber Repair - Hydrotail [Raptor] [In reply to]	Can't Post

Scuff the area with 80 grit paper and thoughly clean with acetone.
4-5 layers may be over kill, but you dont want to repair it again

ghc19127

Oct 6, 08 5:28

Post #5 of 8 (174 views)

Re: Carbon Fiber Repair - Hydrotail [Raptor] [In reply to]	Can't Post

In Reply To

The hobby shop may have a carbon strip that you can also attach with epoxy. I would use at least 4 to 5 layers of fiberglas.

I should have figured a hobby shop might be the place to go. The searches on Google yield results on repairing things like model air plane wings and surfboards.

Three follow up questions.

1. Any recommendations on how wide the strips should be. I'm thinking of 2" strips to run the length of the crack. Too wide or not wide enough?
2. Is it better to put 4-5 layers on one side (I would repair the inside) or 2 layers on each side?
3. What is the advantage of using a strip of carbon fiber? I'm assuming it is just aesthetic.

Thanks!

beaker

Oct 6, 08 6:39

Post #6 of 8 (137 views)

Re: Carbon Fiber Repair - Hydrotail [ghc19127] [In reply to]	Can't Post

I am PM'ing you to just warranty it. That is the easiest way!

SLC_vt98

Oct 6, 08 6:46

Post #7 of 8 (132 views)

Re: Carbon Fiber Repair - Hydrotail [ghc19127] [In reply to]	Can't Post

1. Any recommendations on how wide the strips should be. I'm thinking of 2" strips to run the length of the crack. Too wide or not wide enough?
match the width of the carbon that you are repairing.

2. Is it better to put 4-5 layers on one side (I would repair the inside) or 2 layers on each side?
Just the one side (on which the fibers are broken). you are basically sandwiching in the broken fibers. If anything add a single ply on the outside or perhaps one of the carbon chain protector strips if the fibers look whitish on that side (sign of the fiber delaminating). Note that your number of layers will depend on the repair fabric that you use. Less plys with heavier fabric. Honestly, one ply of a surfboard grade fiberglass should be plenty.

3. What is the advantage of using a strip of carbon fiber? I'm assuming it is just aesthetic.
weight, but it is pretty minor in this case. Most of the weight comes from the resin/epoxy. You could use kevlar too. Carbon does not fatigue well (when it gets bent back and forth) the fibers rapidly break down. That said. do not play around with the broken piece anymore than you have to.

Another option would be to glue on a rail (some thing that fits around the edge like a tongue and groove joint) over the top and bottom edge of your hydrotail.
that should also restore your lateral stiffness.

...
Run like you stole something

ghc19127

Oct 6, 08 9:13

Post #8 of 8 (91 views)

Re: Carbon Fiber Repair - Hydrotail [beaker] [In reply to]	Can't Post

In Reply To

I am PM'ing you to just warranty it. That is the easiest way!

I'm not used to doing things the easy way. I tracked down a local hobby shop and was heading over around lunch time. Looks like I'll have to find something else to do now.

Thanks to all for the advice. Even if I don't put it into practice this time, the general knowledge is beneficial.