Fin for a Hawaiian Gun

General Discussion
1

I’ve been asked to make a custom wood fin for a 10’6" Hawaiian gun collector board. Could someone give me some advice regarding an appropriate shape and size for such a board. what would be a propper base width, depth length, and rake? Thanks much for any help!!

2

Hey RM

Would depend on size of rider, width of tail, width of widepoint, thickness of board, and is it really meant to be surfed in 12’+ waves.

For sake of argument…7" base, 10" tall, swept back, of course.

But that is just a general recommendation.

My #2, a 9’10" x 19 with a 9" pintail had only a 8.5" x 4.75 base single fin, and it was plenty big to do any job for a lightweight 135 lbs. rider.

Generally, with a base of the fin over 6", you’d need a thicker foil section to be able to keep some semblance of a “foil”, to prevent straight spots in the fin foil which can lead to cavitation.

Placement is especially tricky, as little groundwork has been laid in that regard.

I placed the trailing edge of the fin somewhere around 14" up from the tip of the pintail, trying to visualize exactly where my back foot was going to be placed.

3

Thanks much LeeD for your reply. The fin is for a “show board” and likely won’t see any north shore type action. Just trying to produce a fin appropriate for this gun shape. Since I’m obviously not checked out on fin shapes for a large gun style board, would you suggest more of a pointed tip at the outside of the rake or rounded off curve? Any specific peculiarites to the shape outline for this particular style fin?

4

Check out Paul Jensen’s work in the archives.

5

Hey

Keep it swept back almost 45 degrees, but slightly more straight up actually.

A curvy planform does stick better and flows better.

Straight lines have less drag and can go faster.

No real rules here, but a curvy swept fin looks athestitically cool.

6

Hey LeeDD,

Thanks again for your input. I finished it up today and it’s now at the glasser. It will go on a gorgeous 10’6" Gun that shaped by Michael Hynson while he was here on Galveston Island last Fall (check out the article in the latest “Longboard Mag”). I’ll try to post a pic once the board is finished.

Richard