Maybe some of you surf fiends might find this info interesting, maybe not.
I’m a 23 year old surfer/kneeboarder from southern california. I’ve been in and around the ocean since age 6.
Sometimes I get pretty inspired by all the knowledge you guys here have, and all the cool stuff and craftsmanship going on.
I don’t have any experience with laminates other than fixing my own dings. But I do have some experience with metals and mechanical stuff.
The last six months I have been surfing my 6-0 x 12 x 19 3/4 x 15 x 2 3/4 single fin (what amounts to a heavily concaved CI single) a lot. I have surfed probably 2 months each on a 8.5" tk flex, a 9" stage six (refoiled by me because the stock one wasn’t square enough for my liking, the result being the ‘paddle’ coming out a little more rounded.) and one of rich’s 7.75" mentals a fairly stiff base with more flex at the tip. All fins are valid designs but I spent most of my time on the mental or the paddle. Mostly because the fin tab on the tk is in the front, limiting maxing the fin forward.
The conclusion I have come to with all of these fins is run the fin as far up on the board as possible, and adjust your weight distribution accordingly.
A couple weeks ago I became curious as to what a fin out of aluminum would run like. I found some scrap 3/8’s 6061 t-6 (went to get 5052 marine alum on a suggestion from solo but they had no remnants of this type) for 15 bucks.
Took it home and cut out a 9.0 stage six (I actually added 3/4" of depth to the paddleoutline, and notched the base allowing me to run the fin an inch further up than the box would allow) with a jigzaw, and sometimes sawzall, then got a’ grindin’.
4 hours later I had a damn square alum version of the stage six.
Observations: Weight is 13.5 ounces. The original glass version was 8.5 ounces.
A stereotype of Aluminum would be ductile, soft, and weak. But with heat treatment that thing is solid. I locked the glass version in a vice and could flex it 3-4 inches at the tip, relative to the base, until I heard the faintest crack.
With the alum (keep in mind the foiling was very similar, actually a hint thinner in the blade) I could barely budge it an inch while wailing on it with an open palm.
I surfed this thing in pretty weak waves and could turn as hard with speed, and link as many turns, as with any other fin I’ve had in the board.
Well I kind of learned all I wanted out of it so I went all out and freakazoided the thing for fun.
I cut an inch (squared up to the base)off of the bottom tip of the blade. The result is a little wedge that resembles a 5 fin bonzer side runner. I made a pair of these and welded them to the base in a miniature upside down y style. Also made 4 relief cuts in the leg to encourage twist in the right direction.
Surfed it today in chest-head high lowtide semi mixed up but some fast walls to race waves.
Observations on first go out relative to how most fins feel in the board:
slower paddling into waves (increased area/drag)
more difficult to go rail to rail, change direction
First couple waves definitely noticed the nose kind of lift on the pop-up/upper half of wave on dropping in. This could be from poor angled attachment/foiling of where the 3 planes come together? Or natural occurence from more area in the tip?
Frontside bottom turns (on waves with some push) had heaps of drive. Some waves I would take off deep expecting just to feel a little bottom turn on the closeout, and ended up making the section (or two !). (no wiggle or two-stage, just angle, drop and even pressure on the bottom turn)…it was very noticable that I covered a lot of distance on a bottom turn. Seriously, one semi-holow I dropped in, ran it a bit into the flats, leaned, kicked out and I was like 40 feet from the people at the peak. Like running the TK Flex mid-rear-box, but not as stiff on topturns or cutbacks…you could still overpower it if desired. Extremely fast and lifty(?!) feeling when roller coastering/racing sections. Also, took off one one of the bigger sets (good shape) kinda doubled up-hollow, someone hooted, the heart raced as I went over because I have slid out on bottom turns in similar situations, with fins further back than I was running. Out ran the goddam section in one smooth bottom turn, kicked out. Pretty stoked feeling to be leaning on something you’ve built with your own hands and not eat sh!t!
Overall these experiences have been educational and fun. (you get stoked wondering what its gonna feel like the next time you surf). Nothing mind-blowing but interesting and I made some surprising sections and did a couple ok turns.
Pictures and updates to follow…
edit- oh yeah, this was all standup stuff I only kneelo 10 percent of the time on certain waves in certain moods.