you could try a wrap of tape on your barrel nut, or cut a small wedge of plastic material
and install it with the barrel nut to tighten the nut in the bore.
You could also put some filled epoxy on the barrel nut and install it, but push it out the other side.
When the residual filled spoxy left in the barrel nut bore in your fin sets up, I think you will find the nut fits nice and tight.
I would not do anything to the finish on your Lessacher Design Duo fin.
Wolfgang makes some of the fastest fins in the world, and I'm sure he has done his homework and research (not to mention testing with some of the world's fastest sailors) and knows what finish is fast on a fin, and what finish is not.
Others have decided to "polish" Wolfgang's fins, and that's the last we ever hear from them, so I suspect that polishing or changing the finish is not a good idea.
I really have never seen a really fast fin that was highly polished.
They all have a somewhat dull finish to allow a good "wet out" to cut down the boundary layer.
Water slides best of water molecules on the fins surface. Water does not slid best on a polished surface with no water molecules adhereing.
Hope this helps,
Last edited by Roger; 20th May 2008 at 08:00 AM.