How to Repair a Windsurf Board
Here is a brief tutorial on how to repair a hole in your composite windsurf board. Before attempting any repair its key to make sure the board is fully dry so you don't trap any moisture inside when you seal the holes. Make sure you have all the supplies to hand at the start because once you mix your resin, time will be restricted.
Supplies
2 Part Epoxy Resin (Depending on the size of the repair)
Carbon Fibre
Scissors
Packaging Tape
Gloves
Scales
Mixing Pot
Mixing Stick
Below is a useful link that has most of the stuff you'll need for a small repair:
Preparation
Make sure the board is completely dry before starting any repair: If the damage occurred on the water then tilt the board so the hole is as low as possible and leave somewhere warm for at least a few days.
Sand Back the Paint
Use a light grade sandpaper around 120 Grit to remove the paint. It is important to get rid of all the paint in the surrounding area so the new carbon can bond well to the board. It will also help show exactly where and how bad the damage is.
Get All Your Materials Ready to Go
It is useful to prepare all the materials you will need. When you are ready, mix up the epoxy resin: refer to the container to see what ratio you need to mix this (for example 2:1 resin to hardener will mean you need to mix around 60g of resin for 30g of hardener for a small hole like the one shown.)
The two key things to remember are measuring the proportions of resin to hardener with the scales accurately, and mixing them together thoroughly.
Paint Resin and Add Carbon
First mask off the area around your damage with packaging tape to limit where the resin can go. Then get the resin into the hole and apply a bit to the surrounding area using either a brush or a finger.
Add a piece of carbon fibre and make sure its completely wet before adding the second layer on top. It is better that you have a bit too much resin because too little can leave air bubbles that will reduce strength and may leak water into the board.
Leave to Dry
Add some tape over the top of the carbon so you can touch it without getting coated in resin. Then add some weights on top to compress the carbon onto the board. In this case I used a heavy box.
Ideally leave the board to dry somewhere warm: this will speed up the time for the epoxy to set and if the board is kept too low below room temperature, you could run into issues.
Sand the Excess Carbon
Consult your epoxy container to see how long it takes to cure. Once you have left the board for the allotted time, you can peel back the tape and begin finishing the repair.
You will have excess resin and carbon on the board so sand these back in the same way you removed the paint before: until the surface is nice and smooth. You can use a coarser grade sandpaper to remove more material quickly if there is a lot there.
Once the Board is all smooth again, the repair is finished.
Paint (Optional)
If you want, you can repaint the board so you can't see the repair anymore. To do this I would use a spray primer and paint and use tape to mask off any areas you don't want to paint. I tend to prefer to leave the board unpainted so you can see if anything happens to the repair.