No worries, i did not take it that way.
I am not trying to be argumentative nor insulting . I like your threads, input and experimentations regarding fins and board design and ability to think outside the box and value your experience and willingness to share.
So since i had your attention, tried to hold it. Your bringing up the FCS h2s alone was worth it. ;)
If I were on Oahu, I'd be asking you to put my SharkyHARs in one of your proboxxed boards to try. Still might, when I make more and refine them some more...
Funny how the H2 hasn't recieved the attention I thought it would get, but now everyone is making the hollow foil on the side fins and they all have their favorite shape. One thing I need to research is the H2 in a position (cant and tow) that it wasn't designed to be used at. I do know that they have a unique hum in the zero cant boxes, but I didn't hear it in another board I have. I'm not going to let that hum stop me from using them the way I've been using them, but I'll have to see if they are even better with more cant. Lots of things to check out this summer.
I did not realize the H2's had a concave inside foil on the rail fins. How much more toe in do you think the offset fcs tabs add? How deep is the concave?
I don't find it very surprising such fins never got much attention, as they look so far outside the expected dol-fin shape that both surfer and non surfer eyes have been trained to expect, and the general surfing public are a bunch of sheep who must be fed what they expect lest the whinge fest begin.
I have made 70/30 and 80/20 foils in the distant past, just moving the center line over and trying to lightly foil the smaller convex side, but these never seemed to have the responsiveness and projection of a flat sided rail fin, and are harder to make. They were however smooth and predictable in larger more powerful waves.
I am now just making my rail fins now with flat sides, not only as it is significantly easier, but they feel better, even though the flat sides make little sense from a design standpoint. I keep trying to get MrMik interested in designing and printing rail fins now that his large single fins are highly refined and reliable performers. I embarrassed myself when he referred to inside foils as 'cambered foils', and I was unsure what he meant though that the correct term.
The latest center fin I modified to fit Probox, I glassed over the 3d printed PLA with two layers of 1.43oz cloth and did two thick hot coats. I sanded it to about 85% in a rush, and went surfing in some very fun conditions, and the fin was almost always humming, each and every wave, 90% of the ride. Easily The most prevalent fin hum/whistle I ever experienced.
People I passed were commenting on it, as my hollow board helps that noise to resonate like a guitar. The humming on a few hard frontside bottom turns became ridiculously loud, then the tail started drifting shoreward with a loss of drive. I really liked the fin combo despite this. and just kept from pushing those frontside bottom turns as hard, then the wind came up .
Afterwards, I spent more time wetsanding the hot coat and sharpening the last 3/4 inch of its trailing edge.
Next session it was completely quiet, not a single humm/whistle, and I was not able to overpower it, but had few frontside waves and none of which allowed a hard frontside bottom turn in the flats, and the conditions were smaller/weaker. I cannot say the overpowering of it the previous session on hard frontside bottom turns was due solely to the humming/ inaccurate foil/fat trailing edge, but I suspect it played a significant part.
Pretty much every fin that hums, when I inspect closely and then razorblade scrape/wetsand on a block the trailing edge, the humming stops. I am not making it knife sharp by any means, just thinning out the last 3/4 to 1/2 inch of the foil and blending it into the rest.
I had the carbon TC redline center fin hum sometimes in my newest HWS, but it never hummed in any previous board I rode it in. When I sanded away some of those white and red paint lines to thin the trailing edge, no more humming.
So I'd take a close look at the trailing edge of your H2's. There might be a slight round near the trailing edge, from the spray on glossy finish they applied, that likes to form a bit of a ridge, especially if they sprayed it on thick.
I take fin humming/whistle as a sign something is wrong, and a few longboard fins, when they would start humming, the board would seem to go dull underfoot as long as the humming lasted.
When I was trying the injection molded wavegrinder winglet fins both the 4.8 and 5.7" deep ones, in my board they would also humm, and when the humming started I could feel it in my feet and the board would go dull. I was able to stop the humm by tuning the trailing edge on these too, but I never was able to click with those fins. I think the winglet angle needs to match the tail rocker of the board and then in certain parts of the wave it feel rocket like, but in other parts it feels weird and unnatural and kind of tracky.
The large wavegrinder WG2 fin in my one 9'3" longboard with less tail rocker, worked very well, but would track sometimes, it worked much less well in my 9'7" with more tail rocker.
Mr Mik made a printed version of the WG2, and I broke the winglet off hitting bottom. I rebuilt it with some Bubinga wood and changed the angle of the winglet so that it would 'dig' less, and that fin would be an absolute rocket in the trough trimming past sections on my bigger LB, where the fin whose winglet would dig more was rocketlike with the tail up high in the wave.
This inconsistency of the WG2 fin design became more noticeable when I started trying his turbucled fins, which did not seem to favor the top or bottom of the wave face, and were much more forgiving and predictable all around, but they were not as quick as the WG2. When I first tried his GullWhale design which is even higher aspect ratio, I was a bit blown away in that it not only turned well and was intuitive and predictable, but had the speed of the WG2 as well and not just iup high or down low on the wave face. Any other fin design ridden my LB is a tremedous let down now.
So this is why I am now so willing to try/experiment with designs so far outside accepted norms, and am becoming tremendously biased against the standard dol-fin shape the more I try other designs, as unconventional and as weird as they look.
I think the H2 fins have 1/16" of toe built in. The H2s will only hum when you engage them hard. I've had the same thing happen with single fins, where they will hum when I stomp on the bottom turn. The hum is more like a buzz. I also think it may be only on the lower cost glass flex versions I have. I think the fins I last used in the board with 5 degree FCS fusion boxes is made with texallium and they seem a bit stiffer than the glassflex version. Those fins are mediums and the glassflex are large, so there are several differences that may be why I hear or don't hear the buzzing. I also use them in my shorter performance boards.
This company in Indonesia makes the H2 fins in 3 sizes and you can get them in 3, 4, or 5 fin sets. I haven't bought from them yet. I got mine new from FCS and used from other people.
My brother gave me the Wavegrinder fins years ago, both the center and sides. I still haven't been able to get myself to try them, but one of these days I will give them a try. My brother said they work best in low rockered boards.
A buzz rather than a humm is strange, but it occurring on a hard bottom turn is pretty much where I now expect fin noises to appear most often and at their loudest. I have always, so far anyway, been able to stop it by tuning the trailing edge of the fin.
Regarding the wavegrinder fcs1 tabbed fins, they do sit a bit proud of the hull, and one can likely sand the forward or rear tabs to adjust the winglet's angle, though I am not going to bother. The 4.8 inch deep pair is not actually in my possession anymore, have not seen the guy in many months, and the 5.7's, the last time I rode it in my 6'11's center box felt absolutley atrocious, to the point I considered kicking it out shearing the tabs, and finishing the session as a twin, but the wind came up and I got out before I did so.
WG wingletted fins working better on flatter rockered boards makes sense and is my experience with the larger WG2 on 2 longboards, and the 3d printed clone whose winglet broke and I modified its angle when I replaced it.
The 50/50 foils of the WG fins, as rail fins, might be part of the reason I do not like their feel. Perhaps they need zero tow in and zero cant...... Either way I so much prefer the feel of the other fins I have been experimenting with, and am not too stressed if I never again see the guy to whom I lent the 4.8's, and if someone wanted my 5.7's, they'd get a deal on them, as long as I don't have to go to the post office. As far as the large longboard sized WG2 goes, it is too flexible for me, and Mr Mik's turbucled G-whale fin outperforms it in every way by a significant margin.
The WG fins started my whole foray into High aspect ratio, and the ensuing joy, so I am thankful for their existence, but the winglet has a narrow sweet spot in the wave where tail/hull rocker and winglet align to give that drag free feeling burst of speed. The WG2 also feels like it sometimes dictates the line taken, causing me to go further out on the shoulder before being able to turn. It does however feel really good on the downturn from high up in the lip accellerating almost unnaturally into the pit. I'd certainly be riding it often in place of my regular Dol-fin in my LB, if I did not have turbucled Gwhale fins which are speedy happy go lucky frothers themselves.
Every time I start making new fins, it is as I forgot how labor intensive they are, especially when making a pair of rail fins and trying to keep them symmetrical.
Below left to right is the recycled 3d printed 0.45GWhale fin, whose tab I just extended to allow it to sit further back in the board, a FCS 'rusty' fin from teh 90's, my latest unfoiled cedar sharkyhars, an the purple fin is Mr Mik's Albatross whale fin cut down in size to fit probox. This fin needs to sit further back on the board by at least 1/2 inch and will get modified as the 0.45GW did.
Very much liked the 0.45GW with larger sharkyhars before I modified the tab, but it was not enough fin with the smaller sharkyhars. The 0.5GW's felt much better with them, sitting 1/2 inch further back and being slightly deeper.
My sharkyhars are deep fins, as is the purple 0.5AW fin, but they feel less draggy than the Tc redline sized normal fins and certainly pivot faster.