So i bought a very cheap 2nd hand 70cm fin to try and get going earlier in light winds.
I noticed it had some very small lumps on the surface (1mm diameter?) More on one side than the other. I assume it must be some sort of minor delam from being wet all the time? (The fin was soaking in its case).
So i decided to sand them off. Feels much smoother now, but ther are very small arc shaped notches left on the surface where the lumps were.
My question is, what should i do about them. Should i try and seal the notches (also how to seal them?) or just let them be and go windsurfing?

Yes its a drake fin. Using it on a jp slw 168l 2016. Taken it for one run pretty powered up with no issues before sanding it down. But it did feel a bit draggy (compared to my 56cm stock fin) hence the sanding..

I wouldn't be to worried unless doing over 30 knots? not as ugly as some of me reef biting fins

maybe wet and dry sand paper 600 will smooth it out ,

I think this may be paint reaction. The epoxy remedy, would need to adhere to the surface , not paint.
1. Remove offending area or all, then epoxy, I think 2stage Of Gorilla or such would be ok.
2. Leave it alone as suggested.

i would probably remove the paint at least I think what it is, skim coat epoxy, probably repaint. That's me.

I would not fill with epoxy as it is harder, and when sanding back then the paint will sand off easier, and you will still not have a flat surface. Squirt of hi build primer and sand back. Advantage is its grey too!!!

Mark _australia said..
I would not fill with epoxy as it is harder, and when sanding back then the paint will sand off easier, and you will still not have a flat surface. Squirt of hi build primer and sand back. Advantage is its grey too!!!

Any bigger flaws that the primer won't fill, use a bit of spot putty. Dries quickly and sands easily. If you use epoxy, you'll send a lot of time waiting for it to cure and sanding off all the gob that went in the wrong place.

Thanks for the input guys. I ended up putting a thin coat of epoxy filled with graphite and glue powder and sanded off before it went fully hard. First run yesterday fully powered up with 9.8m sail and had a blast!

BSN101 said..

sun fisher said..
Thanks for the input guys. I ended up putting a thin coat of epoxy filled with graphite and glue powder and sanded off before it went fully hard. First run yesterday fully powered up with 9.8m sail and had a blast!

what was the wind strenth? Im thinking about a 70 too

Im about 97kg, but not very good at pumping yet. I think i easily got going in 15kts maybe a bit less and it was gusting around 20kt later in the arv and was still controllable - ish