OUCH! G10 EXAMPLE
The below G10 fin has severe scrapes on the leading edge.
The intention is to bring the leading edge into its original state and profile.
Note – we will not in any way modify the edge to get rid of the scratches and dents. Start with grinding (sandpaper 120 grade) a little bit over and around the affected area. This to make sure no dirt or grit is left behind.
Regular epoxy resin will be used and 3M magic tape is used to guide the epoxy.
It is put on one side of the leading edge. Don't push too hard on the tape - epoxy must be able to find its way into the smaller scratches as well.
Put the fin on a table - as seen on the picture - and raise the tip a little - until the leading edge becomes horizontal. This to keep the epoxy resin in place.
Start with a few drops of epoxy along the affected area.
You will see the resin will flow nicely along the edge and under it.
Also, to fill the dings fully in one go, wait till the resin is starting to thicken a bit so that it’s easier to fill the bigger holes.
ADVICE - SAND IT BACK AS MORE IS BETTER THAN LESS
Make sure you add it above the original fin form.
Too much will not hurt as it’s easy afterwards to model the shape by sanding it back.
BACK TO SHAPE
Wait a few days at least to make sure the epoxy is fully hardened to allow for easy sanding.
Normally I use 120, 240 and 400-grade paper and a ridged foam block to bring the form back. Start with 120 and so on.
For bigger, more serious repairs 60 or 80 could be used first.
The repair is now finessed and acceptable both from an optical as well as performance point of view.
When repairs are performed on black finish type of fins, a black Edding pencil could be used to cover the repair area.
When fin tips must be repaired it is advisable to use chopped strands of glass or carbon. This to withstand the high forces when hitting the ground again.
This technique will work for most fin materials such as glass fiber, Vinylester, carbon and G10 but not older ABS plastics or modern Nylon plastic fins.
Post by Caspar Verhaagen Product Development and Testing.