How to Repair a Damaged Composite Canoe or Kayak – Carbon/Kevlar Fibre

How to Repair a Damaged Composite Canoe or Kayak – Carbon/Kevlar Fibre


Hi welcome to this Easy Composites tutorial
on kayak repair. What we’re going to be doing is looking over this boat, it’s had a bit
of damage and just going through the different areas and showing you the best way to repair
that. So let’s take a look at the damage that we’ve got. On the sides here it’s had a crush
and it’s fractured the laminate just down here and again the same on the other side
so we’re going to be creating a patch to give it it’s rigidity back and to stop it from
leaking. We’ve got another area here which is where it’s taken a hit and again it’s taken
out the top coat of the resin. And then at the nose of the kayak here we’ve got damage
to the Kevlar joining trim and also just on the underside there’s quite severe fracture
just here which again we’ll be doing a patch just over the underside of the nose there.
First thing you need to do with any repair is make sure that the area is fully prepared
for the bond. Now to do this you need a very coarse abrasive 120 grit at the finest. Really
anything down to between 80 and 120 is perfect. Any loose bits of material remove those with
a knife or chisel, or sand them away until you’re back down to the most solid material
you can find underneath. So we’re just looking to thoroughly sand the area beyond where you
see the fracture because very often with composites the fractures run a lot further than it looks
like on the surface so your patch wants to cover a good two inches fifty millimetres
beyond the edge of the visible cracks all the way around. Now we’re going to look at
the Kevlar edging tape. It’s important with this any damaged areas cut them out and remove
them and then just lap another section of the tape, the braided tape, over the top.
So the first thing to do is as I say cut it out. A sharp knife’s the best way to do it,
if you try and sand Kevlar it goes very fluffy and you’ll soon end up in a mess. In this
nose area we’ve got quite severe damage that’s a full fracture into the hull. So what we’re
going to do here is build up an extra patch of material just over the fracture and then
another one that laps over the top and then finally once we’ve done that we’ll bring it
over the tape here and then we’ll lay another band of tape over the top and lap it all together.
So now we’re going to cut the material for the repair. Here obviously we’re using a carbon
Kevlar. That’s clearly what this hull’s made from. However it’s quite common to have Diolen
hulls. The same resin systems and the same processes all apply. Likewise with some of
the racing kayaks they’ll be full carbon and again you can do the repair with full carbon,
or indeed on more basics ones just fibreglass. So the process remains the same it’s just
a case of precutting you’re material, getting everything prepared before you actually mix
the resin and go in one the repair. Kevlar can be notoriously difficult to cut. Here
we’re using Kevlar shears, they do make your life significantly easier, and it also results
in an easy repair. We’re now going to be using Kevlar flat braid which is commonly used around
the edge of the kayak for joining the upper and lower hulls we’re just going to be using
it around that front area where we’ve got the damage to the original braid. this is
release film it’s a very thin, fairly stretchy film that is designed not to stick to resin.
So once we’ve done the repair over the front we’re going to be using this and stretching
it over the repair to give it a nice smooth even finish. Now we’re going to mix up the
resin we’re using Easy Composites rapid repair resin. It’s got very high flexural strength
which means it can flex without cracking and breaking which it obviously important on a
kayak and it’s also got very very good laminate bond strength to existing either polyester
or epoxy hulls. So that way your repair will stay firmly attached and won’t peel. It’s
very impotent that you mix resin as accurately as you possibly can, so a good set of scales
and thorough mixing is really key to making sure that your repair is sound. First looking
to brush resin over the repair making sure it penetrates really well into any cracks.
Now apply the first layer of reinforcement. You can see immediately when the resin is
wetted into the fibre thoroughly. The second layer of reinforcement that we’re applying
overlaps both the seam on the tape and the first layer. You need to be very careful around
any areas where you’ve cut the fibre. If you’re too rough with it it’s very easy to fray it
and although it won’t structurally affect the repair it won’t look as neat. Once you’ve
wetted out all the fibre nice and evenly, just give it a little brush over with a little
bit of extra resin and then when we stretch the release film over the top we can squeegee
that out and it will leave a nice consistent even finish. What we’re going to do is trim
off the excess of the release film and then we’re going to tape it back to hold it tightly
over the repair. The odd little wrinkle won’t matter that will soon knock out and smooth
out on the final part. Once the repair has been filmed over, any small air bubbles that
you see inside can just be pushed to the edge underneath the film. As you can see you end
up with a very smooth consistent finish. That’s now ready to be left. We’ve used a fast hardener
so the release film could be removed from that in as little as three or four hours,
so we’re going to move now onto the other repairs. I’m just wiping over the area here
with an alcohol wipe just to degrease it thoroughly and make sure again that we get as good as
bond as we possibly can. We’re using a slightly different technique here on these side things
because they’re more complicated and it’s very awkward to get brushes into there we’re
just going to be wetting out the fibre on a piece of release film on the table here
and then taking that and placing it onto the hull of the kayak as you’ll see. Right I’ve
mixed up a new batch of resin here ad we’re going to just apply that down onto both the
hull itself and onto the reinforcement here because you still want to make sure you’ve
got the coat down even though we’re using the patch method, coat down on the part to
penetrate into the fibres that are exposed there. Using this patch method on the sides
is very straightforward once it’s all wetted out we simply apply the patch down onto the
surface pressing it firmly against it to make sure it’s in full intimate contact and then
it’s just a case, as we’ve done on the nose, of stretching the film down as tightly as
we can and taping it down into place. With these side sections it’s quite an intricate
shape so getting the film completely smooth isn’t going to be a possibility to we’ll have
to accept some slight wrinkles that we’ll address later on. Right these repairs are
now ready to be left. We’re just going to use these to cure overnight and then we’re
going to come back to it, look at finishing them up to a nice standard and also putting
a little bit of resin over in that gel coat repair at the front. You can see how easily
the release film removes from the repair. It doesn’t stick at all to the cured resin.
The finish that we’ve got on the nose here is absolutely spot on the release film has
left a totally smooth and consistent finish so we’re just going to look at tidying up
the two repairs on the side of the boat now. Now because we couldn’t get as much tension
on the release film on these areas it’s left a very slight wrinkle onto the surface so
what we’re going to do is just flat that out and coat it with resin to seal it again. When
you’re sealing in fibres here you want to make sure that you go beyond the edge of your
line there that will seal the repair to the rest of the hull. And when you’ve keyed it
up you should have keyed up just beyond the repair because if you were to apply this to
an area of the boat that wasn’t keyed up you’d run the risk of it wanting to come off. Moving
on now to the areas that require a repair to the gel. Having already sanded these back
and prepared them it’s simply a case of using some of the mixed resin and bleeding it into
the surface. We built it up to roughly the level of the rest of the hull and now we’re
taking release film stretching it tightly over the surface, adding a little bit of extra
resin just to get it to the level, completely level with the surface. Then as before just
stretch the film out, tape it down and squeegee it out where necessary to get it completely
flush with the surface. We’ve removed the release film from these two repairs now. The
finish is really smooth and even, we’re not going to sand that, that would risk exposing
the fibres again. So really now that’s all of the repairs on that boat done. That concludes
our kayak repair tutorial. I hope you found all of the information in this video of use
and remember you can buy all of these specialist kayak materials on our website www.easycomposites.co.uk.

44 thoughts on “How to Repair a Damaged Composite Canoe or Kayak – Carbon/Kevlar Fibre

  • June 25, 2012 at 11:35 am
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    keep these videos coming guys!

    Reply
  • November 26, 2012 at 6:44 pm
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    Hey easy comp guys, any chance of a tut on your mould making and resign casting starter kits please?

    Reply
  • January 22, 2013 at 10:10 am
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    Casting is a topic we will certainly cover in the future.

    Reply
  • February 26, 2013 at 2:52 pm
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    You guys need a new back banner. "Competative" pricing? 😉

    Great video though!

    Reply
  • May 30, 2013 at 2:41 am
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    thanks for the tips great video

    Reply
  • June 9, 2013 at 3:39 pm
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    IN no time he is going to get cancer . no respirator or any PPE used.

    Reply
  • July 12, 2013 at 1:36 am
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    Good

    Reply
  • July 13, 2013 at 8:51 am
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    Sorry guys that's a half ass repair. You needed to remove the damage. And feather the repair .

    Reply
  • July 15, 2013 at 1:15 pm
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    To cut out a section of the hull and replace it to completely remove the damage is rediculously over the top for that kind of damage. The repair done is perfectly strong enough, and more importantly and the whole point of the video, is within the means of your average guy. To make a near invisible factory style repair would be both expensive, and likely impractical for people to do at home.

    Reply
  • August 5, 2013 at 8:38 am
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    Hi Leonard, thanks for your feedback. The repair covered the extent of the damage. That canoe's now been back in the water playing water polo once or twice a week for over a year with no sign of weakness from the repair. The purpose of the video was to demonstrate a simple repair that anyone could easily do, not a masterclass. The repair has proved more than adequate and hopefuly encouraged people to have a go themselves.

    Reply
  • August 21, 2013 at 10:04 am
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    This is gold. Thank you.

    Reply
  • September 11, 2013 at 10:50 pm
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    will you guys be making any new video's any time soon?

    Reply
  • September 12, 2013 at 8:47 am
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    We do have plans for further videos in the future.

    Reply
  • September 16, 2013 at 8:38 am
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    I have no idea what feathering is. However I have found this video useful. My slalom kayak is made from the same material as the hull in this video. The epoxy layer on some parts of the hull have worn away making it slightly (only very slightly) soft in parts. Could I just apply another epoxy layer or two, or would I need to patch it?

    Reply
  • October 7, 2013 at 10:42 am
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    Dry the kyak fully to see if the parts are firm again. If they are still soft, then there has been some structural damage and you would be best patching the repair to replace the strength lost.

    Reply
  • October 31, 2013 at 6:15 am
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    i ordered some carbon kevlar and resin from you guys the other day, guess what im doing this weekend.hehe

    Reply
  • November 7, 2013 at 10:19 pm
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    ive done a couple of repairs to my kayak now and the patches look pretty good, but im left with small pits from where there were tiny air bubbles left over,will this have a bad effect or is it merely cosmetic. I wouldnt have had the confidence to do it without seeing this video…

    Reply
  • December 22, 2013 at 3:11 pm
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    need to repair my slalom kayak but first time doing it its carbon kevlar but dont know what things to get to repare it could u reply with a list 

    Reply
  • March 22, 2014 at 2:49 am
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    will it fix my broken, straight leg ,chairs?

    Reply
  • July 30, 2014 at 3:49 pm
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    For the life of me, I can't get this smooth, bubble free, finish with the release film.

    There are always way too many tiny air bubbles, and some are just impossible to move to the edge without accidently & permanently wrinkling the release film (which leaves a line in the finish). I've tried 4 repairs using these steps and have not been able to get the perfect finish yet.

    Can you guys give any more detailed steps or tips for this part of the process?

    Reply
  • May 2, 2015 at 12:11 am
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    Clear informative and relevant. Thank you.

    Reply
  • June 4, 2016 at 6:03 am
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    Your hair is brilliant, almost as brilliant as Milo Yiannopoulos' hair.

    Reply
  • July 1, 2016 at 11:44 pm
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    Is the release film necessary or could something like saran wrap or clingfilm suffice?

    Reply
  • July 18, 2016 at 11:09 pm
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    Is the epoxy finish uv-resistant (i.e., will it withstand outdoor storage)? I know most epoxies are very susceptible to uv damage, and was wondering if this product incorporates inhibitors?

    Reply
  • October 6, 2016 at 5:49 pm
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    Canoe polo!!!

    Reply
  • October 6, 2016 at 5:52 pm
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    where did you get the kayak from? is there a canoe polo player from easy comp?

    Reply
  • October 31, 2016 at 4:00 pm
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    So I bought an Impex Currituck Carbon/kevlar and I noticed (webbing cracks) and a chip in the hull (outside) and a break in the fiber pattern inside. In the skeg box area the finish is breaking away as well. Should this be done by pro, how much would it cost?

    Reply
  • November 19, 2016 at 4:04 am
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    i remember using this 2 part epoxy paste that smelled like corn chips  and it took 32 hours to cure, and was hand workable. I had a friend come to me with his ct90 Honda, that had the chain bunch up and break the casing away leaving a open gap letting all the oil pore out, and I fixed that with the 32 hour resin and fiber glass and Kevlar sandwiched the Kevlar was the main structure the glass was for fill,   as I removed any lose aluminium,  lucky the bolt holes where on both side of the break so I did not need to drill bolt holes,  it  hardened like clay,  slowly getting stiffer, I was able to sand it for the aluminium cover to fit and not lose oil, and that bike worked for years, I sold it and never heard if it still works but it was treated like a dirt bike so you never know wish I took picture.

    Reply
  • March 8, 2017 at 4:30 pm
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    ive made many surfboards over the years in other countrys but never in UK and the cost of materials is very high. ive never used cling film in the proceedure but seen it used in working with carbon fibre can anyone tell me if they've seen it used in the case of ordinary fibre glass and polyester resins and on what products, thanks? I am now making my very first combat knife sheath by using a blowgun on polyethelene plastic sheet 3mm thick. the finish is amazing.I would love to make a guitar case out of this material and also out of this carbon fibre course weave material used on your canoe, but then it all depends on the price of materials in relation economically to the product. I made a rifle case once by joining two plastic kids school cases and cutting joining and reinforcing them and finished them off with angle aluminium metal beading on edge using rivets screws and fibre glass ribbon tape. glass fibre is a beautiful thing. have any of you ever read captain cooks amazingly descriptive paragraphs in the chapter of his first sighting of surfing in the Polynesian islands or probably Tahiti?. Well read it , it will blow your minds. And so that's where they got the name polyester resin. it was name after Poly the Parrot that belonged to Captain Silver in the Polynesians. He kept talkin 'n'singin…….. "did u remember to put the harder in stupid"'!!!

    Reply
  • March 20, 2017 at 10:36 am
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    Relating to the kayak used in the video, what would be it's typical construction? i.e. what weight fabric would have been used and how many layers?

    Reply
  • May 15, 2017 at 6:34 am
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    Cool! Thanks!

    Reply
  • September 13, 2017 at 11:50 am
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    Yo guys, we have a similar boat in our shed that is sort of bent on the line of the joint between the hulls…, we were wondering if you have any experience on recovering the shape? Can we possibly heat it up and soften it and try to remold it?

    We would really appreciate thoughts.

    Kind regards,

    Alejandro

    Reply
  • November 15, 2017 at 3:10 pm
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    Excellent video and workmanship but the top of the boat is called the deck. You kept referring to it as the hull which is the bottom of the boat lower than the seam. I hate to be so picky!

    Reply
  • February 15, 2018 at 10:18 pm
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    Your hair changed 😂😂

    Reply
  • February 28, 2018 at 3:36 pm
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    That's the cool thing about fibers, just patch/glue them and they're good to go and as strong as ever. Can't do that with aluminum.

    Reply
  • March 6, 2018 at 3:42 am
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    If you just have damaged resin could you just apply the resin over the damaged areas to recreate a smooth finish? Easy composites Ltd

    Reply
  • March 24, 2018 at 8:56 pm
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    Used this process to repair a 1/3 scale glider fuselage that had snapped in two places after a heavy landing. The EasyComposites scales are invaluable for correct mix of the EL2 and release film makes life so much easier when applying the wet carbon. Great vids and a great range of products! Thanks!

    Reply
  • December 13, 2018 at 11:24 pm
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    Someone grew some hair lol

    Reply
  • February 25, 2019 at 12:07 am
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    Haaa finally a girl in composites…….haaa

    Reply
  • June 6, 2019 at 9:44 am
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    hi!
    please, what Release Film is this product?
    i can't find it on your website.
    thank you!

    Reply
  • July 25, 2019 at 11:53 pm
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    I am planning a major project using your prepreg products, I was first studying the carbon fiber prepreg but since this cures in room temperature I wonder if it would not be feasible to make my entire project in Kevlar instead. Multi-layering Kevlar, without the need of using an oven must be the simplest way. I want to make a complete dakar rally fairing plus fuel tank for my motorcycle. Would you recommend to do it purely in Kevlar? I will also make a bash plate.

    Reply
  • August 5, 2019 at 10:25 am
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    Damn, take a look at that hair! Briliant! 😀

    Reply
  • September 3, 2019 at 3:42 am
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    Looking for one suitable tools for cutting Fiberglass, Carbon and Kevlar ! https://youtu.be/3e3UqL_vRwo

    Reply

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