Author Topic: Is this how you would repair a carbon paddle that is broken in two pieces?  (Read 12294 times)

magentawave

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I have a carbon paddle laying around thats broken in two right about in the middle and was wondering what is the best way to repair it?

I have never repaired a paddle before but this is how I was thinking of repairing it and please feel free to add your suggestions...

1) Cut and then sand both broken ends so they are straight instead of ragged from breaking.
2) Sand each end about 6" up the shaft to create a grip for the fiberglass and resin.
3) Shape an 8" long wood plug to fit inside each broken end so I can join the two pieces of paddle. Make the wood plug a little smaller in diameter than the inside of the paddle so there will be enough room for epoxy resin.
4) Brush epoxy resin inside each broken end of the paddle and on the wood plug and then join the 2 pieces of paddle.
5) Wrap layers of 2" wide 6 oz E cloth (cuz thats what I have) diagonally along the paddle extending to about 6" on each side of where the 2 pieces of paddle are joined.
6) Run another piece of the same 2" wide cloth from the other direction the same way.
7) Wrap some clear packing tape around the wetted out cloth and let it cure.
8) When cured pull off the tape and do minimal finish sanding.

What do you think? Would you cut the E cloth into 2" wide strips and how many layers of 6 oz E cloth would you wrap?

Thanks  8)
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

addapost

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Re: Is this how you would repair a carbon paddle that is broken in two pieces?
« Reply #1 on: September 18, 2013, 01:36:19 PM »
I am no expert but that sounds good to me. The only thing I would suggest to what you outlined is to epoxy the dowel in just one half of the shaft first and let it cure. Then epoxy the other half onto the protruding dowel when it is solid. That  way you get the dowel positioned exactly where you want it and it does not slide around during the mating of the two halves. Good luck.
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blueplanetsurf

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Re: Is this how you would repair a carbon paddle that is broken in two pieces?
« Reply #2 on: September 18, 2013, 01:48:12 PM »
We have used cutoffs from other paddles instead of a wood dowel.  Ke Nalu shaft cutoffs fit nicely into regular sized shafts and make a stronger, lighter joint.  You might be able to get a piece from a Ke Nalu dealer.
Robert Stehlik
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SUPflorida

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Re: Is this how you would repair a carbon paddle that is broken in two pieces?
« Reply #3 on: September 18, 2013, 02:43:59 PM »
You will create a stress point on each ending point of the wood dowel...a new breaking point...

magentawave

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Re: Is this how you would repair a carbon paddle that is broken in two pieces?
« Reply #4 on: September 18, 2013, 02:48:08 PM »
I thought about that, but whats the solution? Don't put a plug inside?


You will create a stress point on each ending point of the wood dowel...a new breaking point...
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

SUPlime

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Re: Is this how you would repair a carbon paddle that is broken in two pieces?
« Reply #5 on: September 18, 2013, 02:52:28 PM »
I have a Ke Nalu cutoff you are welcome to have. Pm me if you want it.

Beasho

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Re: Is this how you would repair a carbon paddle that is broken in two pieces?
« Reply #6 on: September 18, 2013, 03:09:08 PM »
I broke my paddle in 2 and fixed with Epoxy and Carbon - NO Dowels, NO Mandrels, NO Plug.  Total additional weight 30 grams.
 
1)  Glue shaft, with epoxy (or I suppose you could use super glue for starters).  All you are trying to do is re-align the shaft and get it 100% straight.  Strength is not as much of an issue as re-aligning and avoiding voids.  Just push the frayed carbon back together.   If you cut it it will not be as easy to get straight.
 
2)  I built up a layer 6" long (wide) that was going to end up ~ as thick as original base (e.g. 4 wraps Pie x Diameter).  The benefit here is you are laying up carbon outside of the shaft, so you get extra a bump of moment of intertia from larger diameter.  Key is to tape up a specific distance from break to be sure to know where center of break is.
 
3)  Then I layered up another 4 wraps 1 1/2" on either side of break (e.g. total 3").  
 
A trick I learned from some epoxy Zone Yoda was to load up the fiber with resin ON A SHEET OF BLACK PLASTIC.  Laminating the cloth this way ensures that the cloth only picks up the amount of resin it can handle, and you don't over-pool the resin.

(DW trick here: http://www.standupzone.com/forum/index.php?topic=19921.0)
 
Then peel off the carbon (1st piece was ~ 18" X 6") and using gloves wrap the shaft around the break.  Once dry the fix should be pretty bad-ass.  The final 18" X 3" was used to doubly reinforce directly around the break.

My repair added just 30 grams of weight (20 grams fiber, 10 grams resin).  It has held up to 6 months in the surf (so far).  I was wary at first then just forgot it was ever broken.

See my string of photos.  Note:  02 shows the two halve mashed back together, glued and sanded.  It looked pretty good right off the bat, but probably pretty weak at this point.  Shaft went from 202 grams to 226 grams (1st layer of carbon) to 224.6 sanded, then final 233.3 grams.  Note: the ratio of fiber to resin should be 2:1.  This was made possible by laying up on the black plastic.
« Last Edit: September 18, 2013, 03:18:57 PM by Beasho »

SUPflorida

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Re: Is this how you would repair a carbon paddle that is broken in two pieces?
« Reply #7 on: September 18, 2013, 03:57:59 PM »
I would sugest you orient the fiber +- 45 degrees rather than 0-90....the fiber onth 90 axis is doing less than nothing in this case...just adding weight

Easy Rider

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Re: Is this how you would repair a carbon paddle that is broken in two pieces?
« Reply #8 on: September 19, 2013, 10:37:46 AM »
I have had a few break in the past - I just cut them down and make kids paddles out of them for our demo fleet.
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magentawave

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Re: Is this how you would repair a carbon paddle that is broken in two pieces?
« Reply #9 on: September 19, 2013, 01:05:54 PM »
Yes I will for sure put the glass on a bias. Thanks.

I would sugest you orient the fiber +- 45 degrees rather than 0-90....the fiber onth 90 axis is doing less than nothing in this case...just adding weight
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

magentawave

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Re: Is this how you would repair a carbon paddle that is broken in two pieces?
« Reply #10 on: September 19, 2013, 01:09:46 PM »
Beasho - Thanks for taking the time to post the photos and explain how you did it!
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

blueplanetsurf

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Re: Is this how you would repair a carbon paddle that is broken in two pieces?
« Reply #11 on: September 20, 2013, 10:12:12 AM »
I would sugest you orient the fiber +- 45 degrees rather than 0-90....the fiber onth 90 axis is doing less than nothing in this case...just adding weight

Not true, the fiber on the 90 axis is providing compression strength which keeps the integrity of the round shape.  I learned this from Alex (Native Living Custums) who is an expert at paddle construction.
Robert Stehlik
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SUP-poser

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Re: Is this how you would repair a carbon paddle that is broken in two pieces?
« Reply #12 on: September 20, 2013, 11:15:44 AM »
This company sells carbon fiber tubing, they may have a size compatible with your paddle:

http://dragonplate.com/ecart/categories.asp?cID=52

I've never bought anything from them and can't offer any opinions on their products/service. Maybe they have a tube of an appropriate length/price which would fit the inside or outside diameter of your paddle. I suppose you could taper the ends of the section used to reinforce your paddle to reduce stress point problems? I guess an internal splint would need to be tapered inside the splint tubing. I suppose you could make a wooden plug with a through-bolt to permit spinning the splint tube for tapering with a drill (spin on the drill and sand). If the wood plug isn't completely inserted you could wrap the projecting end with tape to prevent the splint from slipping while sanding.
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magentawave

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Re: Is this how you would repair a carbon paddle that is broken in two pieces?
« Reply #13 on: September 20, 2013, 11:20:30 AM »
Thanks but I think the consensus is to not put anything inside because it creates a hard spot that will be vulnerable to breaking later.

This company sells carbon fiber tubing, they may have a size compatible with your paddle:

http://dragonplate.com/ecart/categories.asp?cID=52

I've never bought anything from them and can't offer any opinions on their products/service. Maybe they have a tube of an appropriate length/price which would fit the inside or outside diameter of your paddle. I suppose you could taper the ends of the section used to reinforce your paddle to reduce stress point problems? I guess an internal splint would need to be tapered inside the splint tubing. I suppose you could make a wooden plug with a through-bolt to permit spinning the splint tube for tapering with a drill (spin on the drill and sand). If the wood plug isn't completely inserted you could wrap the projecting end with tape to prevent the splint from slipping while sanding.
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

magentawave

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Re: Is this how you would repair a carbon paddle that is broken in two pieces?
« Reply #14 on: September 20, 2013, 11:22:07 AM »
And how would you run the layers if the shaft of the paddle was shaped like an OVAL instead of round?

I would sugest you orient the fiber +- 45 degrees rather than 0-90....the fiber onth 90 axis is doing less than nothing in this case...just adding weight

Not true, the fiber on the 90 axis is providing compression strength which keeps the integrity of the round shape.  I learned this from Alex (Native Living Custums) who is an expert at paddle construction.
Pluto Platter: 7-10 x 29.25 x 4.25 x 114.5 liters

 


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