Firstly, thanks for the really useful video on kayak repair! 

What a great resource.

I have two kayaks and three sets of blades which need a variety of patches, and your video has given me the knowledge to start the boat repairs at least!  I like the links to the relevant supplies.

Keying the surface

Is sandpapering adequate or is a better bond created if you sand right back to the carbon kevlar until it is 'fluffy'?  In my local club many people use angle grinders to take back the material this far (risky I know but it appears to be fine if you are delicate); from a structural / bonding point of view is this better than abrasing the existing gel coat and attaching the patch to that?

Advice on other repairs / videos which would be great

They aren't quite as bad as they sound, and I'd rather repair than buy a new kayak.  Most of this kit was acquired second or third hand!! 

I can upload detailed photos of the following problems if this would help you to provide advice on how best to repair:

1. Large area of delaminated / cracked gel coat - I have a large area (about 1m x 40cm) where the gel coat was coming away so I've sanded this back to the 'fluffy' carbon kevlar.  Is there a way to apply a gel coat effectively to a large area or should I just liberally paint it on?

2. Hairline cracks in gel coat - I have a number of hairline cracks (due to age and perhaps too much sun) in my older boat's gel coat.  The underlying material is good and strong.  Is it worth doing anything with this, e.g. brush some epoxy over the top??  Is it likely to be letting water in?

3. Full nose rebuild - The nose on one of my kayaks is very badly damaged - the previous patch has come totally away leaving a big hole.  How would you recommend patching this?  Is there a way to build a nose first then 'transplant' it?  I've heard you can use a balloon to create a shape to mould the end around.

4. Seam not split but not flush at edge - the seam is still holding the boat together but it has come away at one edge leaving a very sharp and rigid ridge about 1-2mm from the hull.  What is the best way to blend this back in? Should I somehow fill the gap or should I overlay another peice of seam tape to bridge the gap? (The sharp ridge runs along most of the length of the boat so I'd rather avoid an additional seam on top if possible).  I'm very reluctant to re-do the seam as the previous owner had it sent back 3 times because of the seam continuously popping

5. Paddle repair - edge split - I have one paddle with a split edge (you can actually see the inside of the blade).  Is seam tape the best way to cover this or will epoxy alone work?

6. Paddle repair - flex on front face - I have one paddle where half the carbon blade face flexes 5 degs towards my hand.  Is the best way to patch this by putting some layers of carbon on the rear of the blade, running across the line of the flex and in the direction of the shaft?  Should I use carbon, or can I use left over carbon kevlar from the boat repairs?  I have this same problem on an older blade where I'm not sure of the construction (it appears to have a foam core and a very thin (single) layer of carbon fibre on top)

7. Seat refit / adjustment - my seat is coming away on one side where it attaches to the canoe.  Can this be fixed with little repair strips?  Ideally I'd like to move the seat back at the same time but I have no idea where to cut the carbon kevlar to get it out (and it's very fiddly in terms of getting a cutting tool in there), nor how to fix it back into position.  Any advice?

8. Bumper removal and refit - Not technically a repair as such, but I notice in the demo video how clean the edge seal is around the nose.  Do you have any tips on how to remove and refit a bumper effectively and especially how to remove all the crud that stays stuck on?  I've only tried it once and the bumper ended up disintegrating.

Many thanks in advance, and sorry for so many questions!