Blade repair

Inland paddling
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G7AFM
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Blade repair

Post by G7AFM »

Has anyone managed to successfully home repair a great chunk out of a carbon fibre blade about 1/2 inch wide inch deep into the blade,
have you been able to keep as an everyday paddle for grade 3/4 or have you repaired & just kept as a spare or used for those gentle paddling trips.

Chris Bolton
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Re: Blade repair

Post by Chris Bolton »

Not actually that specific repair, but I've repaired blades, and I've repaired carbon. It should possible, but if it's in a high stress position on the blade, ie, part that carries a lot of load back to the shaft, it will be harder to make a good job. "Inch deep into the blade" sounds like a structural part; is it solid carbon, or something like a foam infill?

Photo would be useful (you can host the photos on this site now, just go to "Full editor & Preview" and look bottom left).

G7AFM
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Re: Blade repair

Post by G7AFM »

Thanks will get some pics done tomorrow it,s a set of werner player paddles ties gave way on roof rack doing about 60 paddle hit central reservation.

Steve Agar
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Re: Blade repair

Post by Steve Agar »

To follow up on Chris' comments, I would guess that you've taken a chunk out of the outer edge due to impact with a stationary object (a bit of road rather than a rock), but without applying a large force due to levering off the obstacle in question. I think you should be optimistic, therefore, that you can build up the paddle area easily as it's not likely to have weakened the areas subject to the highest stress or stress concentrations (normally the connection between blade and shaft). If in doubt, after the repair, apply a reasonable amount of weight to the blade pushing against the floor (I'm sure you've done this at some time when trying out paddles). A sound paddle won't mind, but if there's an inherent weakness due to the damage, it will soon let you know with a large cracking noise and a pair of splits. If you lose a bit of the paddle area on a grade 4 you'll talk about it in the pub, if the blade snaps off because there's underlying damage that's not obvious you'll probably end up with a few more bruises. Worth brushing up on your C1 technique, as well :-).

G7AFM
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Re: Blade repair

Post by G7AFM »

Thanks Both for the comments after cleaning up damaged area ended up with a 2 x 1 approx gap to bridge tried initially with just filling gap with p38 fibreglass
filler but due to lack of thickness to blade in the area affected any twisting motion just causes the edges of filler to crack,will have to try doing the same but also will need to overlay the blade with fibreglass sheet.

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Jim
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Re: Blade repair

Post by Jim »

P38 is polyester based with a filler medium that is easy to sand, it is meant for fairing not strength.
For a structural filler you want to be looking at mixing up a custom epoxy filler, West do a small repair pack which comes with 105 resin and hardener and small selection of fillers - I would suggest using microfibres to make a thick paste to fill most of the hole, and then microballoons for a top layer to sand smooth.
You don't specify units for your 2x1 hole (mm, cm, inches, I'm guessing not metres) but it sounds big and I doubt if filler will be enough, you will most likely need laminate some carbon cloth onto the blade. As I mentioned in a sea kayak thread the other day I don't like doing this kind of repair because it is easy to make the paddle unbalanced (I do fill small edge chips on my slalom paddles with epoxy and glass balloons), but I know Chris at Design Composites is experienced in these kind of repairs.

Chris Bolton
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Re: Blade repair

Post by Chris Bolton »

There could be some confusion here. I read the original post as a hole 1 inch deep, meaning into the thickness, so near the spine, and I think Jim has understood the same. Steve Agar read it as 1 inch into the edge, so a 2 x 1 loss of blade area. The OP's latest post mentioned "lack of thickness in the blade" so I think Steve is correct.

In that case P38 won't have the strength, it needs carbon fibre cloth and epoxy resin. A photo would really help get the right advice.

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Re: Blade repair

Post by G7AFM »

Sorry was actually p40 fibre bridging filler & yes it is inches as it is from the edge of the blade towards the middle,
Have purchased a new crank so not in any great rush now will have another go at a later date as said in last post will need to overlay the paddle will
add same amount to both ends to try to keep it balanced then keep it as a spare.

thanks guys.

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Re: Blade repair

Post by Jim »

P40 is still polyester based and unlikely to bond well with epoxy which the paddle is most likely made from, however if it is just spacing the glass cloth, it probably won't matter too much.

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