I just made a pair of plywood keel fins to go on a fish I’m shaping. I made them with a 9" base and 5" in height They look freak’in huge. What would happen if I cut them down to say 8" base 4 1/2 " high.
Hey Tuna.
First off, I must admit, that I’ve never tried the 9x5" keels, but yes, you can easily get away with smaller ones. I’ve made two pairs, one 6 3/4" x 4 3/4", the other 7" x 5". I’ve ridden my 5’10 x 21 for two months now with the smaller fins, and it’s very loose, but still very drivey. You can easily slide the tail, but still keep it from spinning out in good size waves (overhead).
I’ve just changed to the larger ones, just to see how big a difference it makes and because I’m off to Indo next Friday, yeah!
Will have to get back to you once they’ve been tested.
I would make another smaller pair, and maybe cut the 9x5’s into two for a quad set-up (check Manuel Caro’s lovely Mandala boards or do a search on canard quad, Toby Pavel, etc etc.
Have fun
Maz
PS! Mine are toed in and canted a bit, 1/4" and 5 degrees, set 7 1/2" from the tips, 1 1/4" (or 1 1/2"?!!??? don’t remember) from the rail.
Tuna,
I don’t know the answer to your question. My first fish with 9x5s made me laugh. I thought,“no way this thing will work.” Its my favorite all around small wave board. It will depend more on the board, how the fins are foiled, etc. than whether you trim off an inch here or there. I’m not an expert. But, I’ve made three fishes with 7x5’s and two fishes(third is almost finished) with 9x5’s. They surf great. Not because I’m a good builder,but, because I make them and that is what is important to me. I suspect the huge fins work if your fish is more traditional wide tailed Lis type, ten inches between tips, big ol butt crack. I made fishes with Future twin fin set-up and did not like them nearly as much as the big keels. Plus,the keels look bitchen. Expert opinion is probably on the way. Mike
I just finished my first board, which is a 5’9" fish, and yeah, they look HUUUUUUUGE, but like Rooster said, it rides great and is way looser than I would’ve imagined. Give it a chance first.
It’s hard to give accurate info from a close up photo with no perspective on the board size but if you want turn the fins for a little better performance just change the leading edge into a more graceful rake and keeping to vertical cord of the fin about 25% off the leading edge of the fin. I think you’ll be happy with the change. But with that said I would advise you to ride it as it is for a while and decide if this sort of change will help the board. In the end you have to have enough surface area on the rail fin to hold an edge in the wave face without causing undo turbulence and drag. It’s a game of getting the most you can out of the least amount of fin because that way you get more speed when you need it.
Mahalo, Rich
Those are a bit Skeggish and Tall.
Seems the ‘keel’ part is missing from those Keel fins.
Quote:
I just finished my first board, which is a 5’9" fish, and yeah, they look HUUUUUUUGE, but like Rooster said, it rides great and is way looser than I would’ve imagined. Give it a chance first.
It was my first try with everything…Just experimenting. I’m SURE I could’ve done a million things better, but hey, you gotta learn somehow…It rides great, but yeah, on my next one I’ll try something different.
Hey, if it works, it works, and if you’re stoked, so much the better… I’ve made hundreds of fish and the keel fins to go with them… The information offered so far is all valid. Depending upon what you are after, certain designs will start to stand out. In regard to fin/keel size for a typical stand-up fish (below 5’10"), you might want to try a base length of about 8-1/4" and a depth of just under 5". Compensate for any resin hoop or outline bead. Triangulate your outline more; as mentioned, more graceful rake on the leading edge. Not such a vertical leading edge coming out of the board. Interestingly, the curve of the tails is very similar to that of the keels; I don’t have an explanation for this… On twin-keeled fish, flat-sided keels snap out on turns, and symmetric foils are a bit gushy. Over the years, the optimum foils seem to be between 80/20 and 70/30, where the “80” is the foil curve facing outward. Hope this is helpful…
Thanks, I’ll take that all in to consideration on the one I’m doing for a friend right now…
From what I’ve seen in twin fins, you have a bit more work to do with the foiling.
Yes, I am aware…Thanks. Without having a set in front of me to go by, I was just guessing/eyeballing. I’m stoked on them, they work good, so whatever, like I said, I’ve learned alot by just even attempting to make my own.
And, if you ever became unhappy with them you can grind them off and put different fins on. But, I would’nt. I’d make a new board with different fins. Any excuse to make another board. I found myself making keels then shaping a board for them. Ride it. If it was’nt better than what I already ride,sell it,and use the money for supplies to try again. Making your own fins from scraps of wood saves you about 40-50 bucks a board and they look so kool, too. Mike
Keep up the good work and have fun w/ your first board. You did a great job!
Hey Dubstar,
What are the dimensions on those gephart keels, about 8 x 5 ?
How do you like that fish from Mannie?
I have a quad from him, I’ve only had it out once but it went really nice!
Take care
JN
I’ll have to measure later, they are fairly long and deep.
I think the 5’8 twin keel is very cool. The first month I had it, most of the sessions were solid H to OH with very strong offshore winds and full 5/3 rubber with hood boots and gloves. I alternated between getting the wave of my life and getting hung up in the lip and air dropping into the tube and oblivion.
The last 4 or 5 times I rode it, I’ve been wearing a 4/3. 2 days were big and clean and the board worked great, my paddling has improved, whether due to less rubber or just finding the sweet spot. It’s very fast and smooth, cutbacks are great but so are big arching turns where you can hit the trim line in with both feet locked together in the center of the board. There’s no need to pump, even in smaller surf.
The last 2 times, it was medium-small high tide and the board is working real well. Much faster then anything else i have and you can actually turn instead of just making the section. You can even pull almost cheater 5’s. I probably wouldn’t have surfed these sessions without the board, or not have had so much fun.
Even kneeboarded a few waves…great board!
PS
The yellow one on Manuel’s site is my board.
Dubstar,
Your board looks absolutely beatiful, and all the things you describe about the ride make me laugh and smile, cause that is just how I felt getting to know my little fishy. That completely effortless acceleration and glide and the big swooping turns.
Next week we’ll see how it goes in Indo perfection.
Thanks to all for inspiration and ideas.
Maz
PS!
Sorry for semi-hijacking your thread.
“The transition between the slow-paddling take-off to the super fast speed turn-on shocks your awareness into a new time frame. The fish has affected a lot of surfers the same way. You have to ride it to believe it.”
I just made some templates for the fish I’m shaping now. The board is 5’9", and the skegs are 7 1/2" at the base, 5" tall, with MUCH more rake from the front of the fin to the tip and not straight down at the back…If that makes any sense. They look dang small, but that might be because the other ones I made were SO huge. Think those dimensions should be ok?? Also, how thin do you think I should make the thickest part of the skeg before they’re glassed? I’d rather go a little thicker than have them snap…
This may not be what you’re looking for, but I had some made at Baines shop and they were 3/16” thick w/o the glass. I had a couple of sets, one of which was a give away at the Swaylocks campout, which were balsawood There are a lot of fin experts here so take my word w/ a grain of salt, but I like them thinner about ¼”.