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The standard surf fin is 30 layers.
I’d understand if it’s a trade secret, but, if not, would you mind explaining that laminate schedule?
we lay up 10 layers per step. 2 layers remove air repeat till you get 10 stop.Repeat 2 more times. Wait 12 hours remove from glass. Trace outlines,cutout,route base,drill holes,foil,sand,fine sand,screen,spray,add hardware and sell.
0/90, 45/45 alternate or all 0/90? What ounce cloth? Resin? Remove air??? By vacuum?
Janklow,
None of my keels, except the old ones I made, have flat spots. This includes keels from lokbox(Made in the Rainbow factory I think), glass ons from Rainbow, and Gepharts from True Ames. Mike
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Shawd,
Thank you very much for replying! I kind of hoped that someone from Rainbow would chime in. This is exactly what I love about the Swaylocks community.
My first introduction to anything other than your typical longboard fin was one of your fins, a Wingnut Cutaway, and I loved it. I still do! I saw the rake on the wingnut sweep, and thought it might catch less kelp than the cutaway which my girlfriend is using, as it has some nice rake. When it came, I noticed the flat sides and was concerned that it might hurt performance. However, I didn’t want to take it out and find out through trial and error, so I posted here. Glad to know that it is to spec, and that the spec is known to not decrease performance. I’m keeping the fin, and if there are problems, I will come to you first next time!
Thanks also for the price breakdown. I gladly paid the $65, and don’t begrudge you for a second the price. Glad that wingnut gets a buck every time someone buys a fin with his name on it!
–Ben
Great post Shawd. Too bad you have to use asia at all, but it’s a competitive market out there today and it’s unfortunately become part of the landscape.
Of course I can’t miss an opportunity to say Wingy had little to do with that cutaway other than putting his logo on it. It’s pretty muchh a rip off of Cheyne’s and Geoff’s bannana fin. It’s certainly not a wingy fin. I have one of Cheyne’s old templates and one of wingy’s and they are pretty darn close. But…thats life in the surf business.
Aghh Yes the Wayne Rich…My Favorite LB fin.
Good choice.
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stay local
Wayne Rich Classic
Wayne Rich needs no gimmick. He thrives because he is a good surfer who makes good functional boards, and this fin is a perfect reflection. Its popularity derives from its versatility as a low area performance template, welcomed by all types of boards.
Prices start at $37.00 Choose Size 7" - $37.00 7.5" - $39.00 8" - $43.00 8.5" - $45.00 9" - $47.00 9.5" - $50.00 10" - $53.00Share with a friend!
nobody still answered these
…what happend with the bonzer side runners, double sided too?
and what with the sidebites in the 2+1 log set up?
thanks
Hi – Thanks for posting. I admire your plan and making fins here as much as possible. All of these points are well taken. Putting all of this in perspective though, I find that what percentage of doing business offshore is relative to the demand of your product. In my interactions with Chuck Ames, regardless of how much of his product is built overseas, he is always working in his shop building and hand foiling fins for his custom market. I’ve never gone in there and not seen him busy with his machines, usually by himself, feeling like you are taking his pay away stopping him from working.
I hope that Rainbow can continue to keep their domestic operation going. Also, I now know that Halcyon makes his living as a plumber, laboring his beautiful fins on the side. I didn’t know that but totally understand the characteristics of that equation.
What I do try to do is help out the local guys as much as possible, make my choices carefully, and try to nourish this art of building surfboards. I do find it harder to paint these scenarios in such contrast as black and white. I respect these other points of view.
hey 11 footer- take that fin and add some bondo to it along leading edge and and smooth/feather it out towrds trailing edge.your 3/8" fin will now be about 3/4" then you can start sanding away testing it each time you sand some off… a pretty simple and direct way to learn a little about fin foils…
Matt,
Bondo! It’s not just for rustbucket cars in the Northeast! I think I might do this, but not on this fin. If Shawd says it is OK, I’ll leave it. Besides, I’m guessing my girl will prefer a shiny fin to one covered in bondo. Just a guess.
I can just see it now. Catch a wave, paddle back out, flip the board, whip out some wet dry sand paper and work on the fin until the next set comes through…oh wait, that would be polluting. Scratch that.
Solo,
I hear you. I still think it is cool that he gets a $1 off of each one, regardless of the role he did or did not play in its design. And just because the template is the same, doesn’t mean the foil is. Just playing devil’s advocate.
–Ben
I know you just meant to add a filler and hand foil from there. But, Bondo is a terrible recommendation. It absorbs water and will crack and fall off when the fin flexes. We have already heard from 11 foot. But, if you choose to refoil any of your fins for testing purposes, cabosil and epoxy on a 60 grit roughed surface will work until you flex the fin and then no filler is going to hold up.
Thanks for your concern. I actually do plan on refoiling a couple of old fins that I inherited, however not using filler. Upon a suggestion by Bill Thrailkill I’m going to use some pu foam, insert fin, foil, then glass. Or, same but using wood instead of foam. If they last, excellent. If they don’t, oops.
–Ben
I use Bondo all the time. Trust me, it lasts awhile. Long enough that I usually have to use a grinder to remove it. Make sure to rough up the surface before applying. A word of caution, cabosil+epoxy is a good idea only if building up a 1/8" or less, (at a time) otherwise it gets so hot that it smokes- just saw it happen to a laminator 2 days ago, not fun. I slop Bondo on 1/2 thick at a time sometimes. Good stuff. 
A good trick is to paint it with rattlecan enamel after you’re done. Then no problems from the water. -Carl
Seems bondo would crack if it was over 1/8th thick as well. Painting it would seal it from water if you used something catalyzed like urethane. I’d think the flex would start being serioulsy altered in a weird way with filler, hence skewing your feedback. Why not just use suncure lam resin and start adding layers of clear glass. Do two or three at a time, then refoil. stagger the fore and aft edges and blend it into the existing fin. This would be as close as possible to having it layed up thicker, without just remaking the fin. As you add layers just hotcoat and fine sand, then go ride it. You could add layers to different thicknesses and try each level. When your happy with whatever thickness you end up with, just re-gloss/re-polish and viola, you keep your girl happy. BTW what is a perfect foil, and who was it made for? What conditions was it tested in? High speed or low speed waves? Beachbreak, reef or point surf? Was it glassy california smooth or 25 knot trade wind bump? Rusty P. once showed me a set fins that had really flat foils that were made in australia, and claimed that they were his favorite fins ever. Super fast and tons of release. Tested in 4 to 6 foot cloudbreak with light offshores. Will they work at cardiff in 2 to 3 foot high tide? Hmmm
Well with fillers, generally you are building up the base of the fin. Usually with a standard fin blank, the thickness vs. the chord of the foil is enough on the “top” half of the fin. You can usually get a nice foil without using any kind of filler- so flex doesn’t really come into the equation. Generally any fin that you are building up thickness all the way to the tip is going to be a low-performance deal anyhow, simply because the thickness ratio to chord length is going to be skewed toward that direction. Simply put, “thin” foil- high speed applications, “thick” foil- low speed applications. I say “thick” and “thin” because of the generalizations, there is so much more to it. -Carl
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if you choose to refoil any of your fins for testing purposes, cabosil and epoxy
Might wanna try epoxy with 3 parts micro’s to 1 part cabosil. Straight cab is extremely hard and a bitch to sand/fair.
If the fin your working with is made from fiberglass cloth and polyester resin stick with the program. Lay a tape line where you don’t what to build up thickness, then laminate several layers of 6oz. cloth with poly resin until you get the extra thickness you want plus some. Use sanding resin for the final layer so it’ll work nicely when it’s cured. You’ll want to sand the area with 120 before you start laminating so you’ll get a good bond. Once the extra layers of lamination cure just foil to suit. When the fin is shaped the way you want it finish with a rattle coat of hot coat as you choose. Done this way the fin well have the same integrity a new one would have. Bondo seems a poor shortcut IMHO. Molded fins are something you don’t want to address with a refoiling project. Most of the complex composite construction fins don’t lend themselves to reworking the foil either.
No Worries, Rich
hey Carl,
“low performance” is not the same as "low speed’. . … . Low speed high performance craft exist e.g some yachts which are optimised for low wind conditions can be described as ‘high performance’ because they use the available energy efficiently. . … . . also there are undoubtedly ‘high speed’ but low performance craft. . . . e.g a Hot Rod with an inefficient engine and large wind resisistance that can still go ‘fast’
The reason I say this is that there is a common assumption that ‘high performance’ surfing means going ‘fast’ or turning hard, whereas in reality performance is relative to the design goal . . . thus a fin designed for low speed applications can be high performance, if it does the job efficiently
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Rich- Yeah, sorry- Bondo is good for rapid prototyping. I forget that the rest of the world isn’t making modifications to their equipment constantly. If I were to set something in stone, it would be with fiberglass and resin.
Roy- Absolutely, I should have worded that differently. Thanks for clearing that up. -Carl (Who uses Bondo to optimize the performance characteristics of his surfing craft regularly!)
Hi all,
Interesting thread. I don’t surf but am into composite construction and find this site full of ideas and interesting techniques. I cannot explain the “feel” of differant fins but I can address why the flats on the fin are not good from a hydrodynamic perspective. Foil theory is very complicated and I don’t understand much of it but I do know enough to shed some light onto the subject of flat sides. Here it goes:
The basic ides of a symetric foil is to provide lateral resistance w/o paying any drag penalty. The best shape for this keeps the fluid in a laminar state where the foil just moves the fluid to the side and brings it back together (two bits of the fluid part at the leading edge and are rejoind at the trailing edge) and everything remains in alignment. If the bits of fluid change positions you have turbulance which results in drag. For this discussion there are two forms of drag: Parasitic and induced. P-drag is created by something sticking out into the fluid and the rate of drag goes up as the square of the speed. I-drag is a byproduct of lift and is greatest at slow speed. There is a cross over between the two curves and this is where the foil is most efficient. Slow down and I gets you, speed up and P is the culprit. Ultimately P drag is the largest contributer to overall drag. Lift is generated when the fluid has to speed up to remain in alignment and laminar as described above. When using a symetrical foil changing the angle of attack (AoA) (what angle the fluid strikes the foil in relation to the chord line(a straight line between the longest axis of the foil)) changes the distance the fluid must move to remain laminar. The point where the fluid seperates is known as the stagnation point(SP). The SP moves as side loads are are added to the foil. When the AoA exceeds about 15 degrees the fluid can no longer remain attached and starts to tumble losing lift and creating drag. The higher the AoA the higher the drag. The drag happens on the top side (side with the greatest distance from the SP to the TE of the foil) of the foil. In severe cases, the water will vaporise and the foil will cavitate. The void created by the cavitation is a very low vacuum and the fluid does not like this and wants to fill the hole. What happens is the foil is easier to move then the entire mass of the water and the lateral resistance is gone because a vapor is flexible and can get larger so the foil loses stability. This action of cavitation and refilling is extreme and the drag becomes very high so the entire craft slows. If there is no cavitation but turbulance the foil has stalled and is no more effective then a piece of plywood stuffed into the water. When the hole is filled or the stall recovered the foil hooks back up and does its job. A proper foil keeps generating lift and resists stalling to a higher AoA then the squared off plywood.
Take a break, have a beer, whatever you want. The reason for the bad flats is coming.
Fluids cannot make corners. They must move around curves. The transistion from any surface to another is a corner and this transition “trips” the fluid and it starts to tumble. As the AoA increases the abruptnes of the corner gets larger and the fluid detaches much sooner. This detachment is the stall or cavitation described above. The abrupt transition causes the stall to occur at a much slower speed and for it to be more severe and require more time to recover. The P drga created by the flats is much higher to. For example: let’s assume the initial drag of the smooth foil is 2 units and the flatted foil is 3 at speed X. Going to 2X makes 4 and 9 and 4X 16 and 81. Starting at low drag pays huge benefits at higher speeds.
There are symetric foil shapes that work better at higher AoA than others. I assume the back end of the board has more lateral movement then something near the CG (center of gravity) or CE (center of effort of the hydrodaynamics of the board) of the entire board nd thus the fins see more radical changes in AoA. The scimitar shape and eliptical tips to the fins are very efficiant regrdless of foiling or not.
I hope my distillation of basic foil theory helps a bit and was not too confusing. There is more to this subject but I wanted an explaination not a disertation.
Thanks for the ideas and help solving unique problems I’ve found the surfing community has discovered.
Take care, Kevin