What follows is a description of the technique I have used to preserve the fragile blade edges of my fibreglass paddle.
These edges are prone to damage when coming into contact with rocks, garage floors etc and the result is the gel coat flakes away exposing the laminations.
All that is required is some cyanoacrylate adhesive [super glue] and a bamboo skewer out of the kitchen. Using the skewer, the glue is simply painted onto the edges of the blades along where the laminations are exposed. It will then soak into the material before it hardens which only takes a few minutes.
Once set it leaves the blade edge with a hard, homogeneous and wear resistant finish.
Additional coats may be applied, the glue dries clear so is not unsightly and acetone can be used for cleaning up.
The product I prefer is an industrial type of super glue manufactured by Loctite. It is grade 406 [for difficult materials], comes in a 25ml bottle and costs about $17. It is very handy for other applications especially emergency repairs but does have a limited shelf life.
A cheaper alternative is the small tubes available from the local shops costing $3. Generally not as good unless you can get the one made in Ireland ie made by Loctite. Apply the glue straight from the tube.