I’ve been to most all of the fin makers websites and thickness seems not to be dimension they want to share. Any experience with this you can share? Maybe a 9 1/2 to 10 inch say 3/4 inch thick?
all the best
Hi Greg.
It’s more about base (chord) length than height if you’re considering thicker fins for better performance.
A thickness to chord ratio of about 13% seems to be a good starting point. So if your fin base length typically measures 150mm for example, your fin should be around 20mm thick at the base.
Thank you RDM
all the best
I don’t think you will find fins thicker than the standard fin box slot, about 3/8". You’d probably have to special order it from Larry Allison.
If you foil fins yourself, you can get thick G10/FR4 panels on ebay cheap. I’ve made fins from panels up to 3/4" thick. Downside is a long thick G10 fin is heavy. Haven’t tried it, but I think it’s possible to add glass to an existing fin and make a thicker fin.
True.
On it. Thx guys.
all the best
SPOT ON.
When I worked at Channin Surfboards in 1970’s, one of the shapers (Tracy Richmond) was very into thick foiled single fins on his boards. He would first cut fin template out of standard glass panel. Then he’d cut out most of the middle leaving maybe 1/2 inch width of the outline. Then laminate on the both sides, a wood panel. When foiled it was beautiful, had nice solid glass edge for strength, and was very light weight. Took a fair bit of extra work but worth it for both aesthetics and performance.
I don’t know Dr Strange. Reminds me of an old thread:
https://www.swaylocks.com/forums/dont-build-your-own-fins-thread
all the best
There is a shaper/friend/customer up here in the Northwest who does his that way.
All true! Tracy was an incredible craftsman and artist. He did it for love really, and because that was the only way he could get the fins the way he wanted for the ride/feel he was after.
There you go. I missed that show. Those look great.
I was looking for the pics Mr Cooper had previously posted on one of his social media accounts some years back showing how he did the hollow base but I couldn’t find them.
I’m setting up to build a noserider for one of my guys and my plan was to use a 1/8th panel of black G-10 for the spine and build the rest out of aircraft ply. I don’t expect it to flex much, though.
Two things.
1. I don’t go for thick base fins on standard noseriders because I’ve found they tend to drag. Tail rocker + a soft edge plus a thick fin just tends to accentuate the effects of the tail rocker and slows down the board. Too much of a good thing.
To the contrary, when a board has hard edges in the tail and moderate to low tail rocker then the thick base tends to set the tail, engaging the edges. The board feels more engaged overall and looser since tracking is minimized. Efficient with reduced drag.
These are my opinions based on the long term use of thick bases, the scientific fin theory guys may come to different conclusions. I do believe that if you were to build a noserider around the fin, with reduced rocker and thin hard edges, then you might be on to something.
- If the bulk of the fin is plywood then I don’t see the need to hollow it out since ply is light. I guess you could cut away the interior of the 1/8" panel before gluing up but not much weight reduction there.
Three things in response:
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I’m humbled you would even reply to me. I’m not worthy to even sweep your shop. Luv your work.
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I am going to do the fin and I am going to take your advice to moderate the tail rocker and go for the hard edge in the tail, probably with some tuck.
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I had no intention of attempting to hollow the base of the fin. And besides, since I have no experience with this combo I was planning on using a box anyways, so retaining the spine all the way through will make that simpler.
Edit to add pic of a 3/4" thick side fin I did using this combo.
Somebody had to post this
Lol and HeHaw!!
I’m not qualified to sweep your shop, either.
@GTate
The simplest variable to control/quantify/evaluate is fin surface area.
(Mass, velocity and fin surface area.)