…seems to me more complicated than to do a panel and then cut and foil the fins…
.and resin + microballons or aerosil + couple of carbon layers is not weak for the tabs?
what are the benefits of this method? besides lightness
thank you
Theres two reasons whiy I want to do this, and they are sort of both the same reason!
I don’t know what makes a good fin, i’m trying to learn as much as I can about them, but it’s a slow process.
So, I’d quite like to copy fins that I know already work, but make them lighter than you can buy in the shops.
Man those plastic fins are heavy.
So this is a way of perfectly reproducing the foils that you know actually work.
Yeah, I sorta feel bad copying other peoples foils, but if they made fins that light for a reasonable price maybe i’d buy them.
The second reason is, when I make my own foils, if I make a set that are magic, then I can reproduce them.
Perfectly. I don’t believe I could hand foil copies of fins anywhere near the same…
So this is basically training for when I want to make many copies of my own foils.
Kit
well personally i wouldn’t copy a small guys work
but i have no problem copying a big company 
especially the ones that don’t supply little guys
I feel KKsurf and Silly allready answered this one.
about the tabs-
these are my first homemade set of fins, I have
test ridden them only twise before I left home
(10 more days to go…and then home sweet home)
seems like microglass+carbon+some chopped fibers are more than enough and I truely hope that in the case of a really
hard collision the tabs will collapse and break instead
of the board.
only time will tell…
…thank you for the answers
but still, lightness is the only advantage that I see
how many times can you use the mould?
because in 20 min you can foil thruster fins
so, in a day you can foil a lot of fins
“in a day you can foil a lot of fins”
If the fins are flat sided rail fins I agree completely with the statement above, but the idea that the world is flat went out of fashion some time ago. IMHO all fins should be foiled with both sides cambered.
Back to the fin shop, Rich
Has there ever been flow testing, similar to wind tunnel testing, of surfboard fins? The flat sided, sharp leading edge side fins, in an academic sense, seem to invite flow separation, the opposite of smooth operation.
FCS has done a considerable amount of research, and Futures I’m confident have as well. I’m working with a few professors and a grad student at the University of Swansea at Swales on a fin design software package. They did tank testing lift drag analysis on all our fins as a base line to compare their software predictions. When the software is finally released, there is a flow analysis program that will be available.
Here is a site you can check:
http://cetic.swan.ac.uk/surfs/products/findesigner/index.asp
not only that
foiling fins in a backyard environment sux imo
i aim to eliminate 90% of sanding and power tools
and stilll churn out a balsa in under 10 ours
good fins are almost a third of the cost of compsand board
ridiculous!
i dont need to foil twenty fins in day
i need tabbed, perfect foam core fins 2 times a month
raptor sell plugs seperately!
a compsand board costs me around 200$nz for materials and then another 100$ for a set of fcs foam core
i cant justify that expense for fins
if they were around 40 to 50 for a high end fin i might change my mind
i have a feeling when i get the process right i hope it will only take around 45 mins hands on
to have a finished set of tabbed fins
reverb,
if hand foiling works for you then you’re fine, no need to change.
I just don’t think I could reproduce the same set of fins more than once, accurately.
So molding is the way for me to do it exactly, and once you’ve set up your systems, you can have a production line…
You could due 100 units at once… theres some time savings!
Y’know, it’s pretty funny, everyone is up in arms about the molded, “pop-out” surfboard thing, but almost every board has pop-out fins on them…
And fins are one of the most important parts of a boards performance.
I think thats really funny
Kit
done some more research
soft molds are an option
so didnt do my money on the rtv
got it pretty much figured out
im gunna start with a center fin
then when thats sorted ill do the three at once
im expecting at least 40 odd sets from a mold before it starts to deteriorate
though i dont really know
i imagine the silicon will peel away pretty cleanly
a good mould can be used around 100 times.
making a good new mould may take a few hours …
you are talking about lightness…
well , as u know , people pay a lot of money just for cutting another gram of their product.
it works in airplanes, bicycle, motobikes, and surfboards as well …
is it really needed? some would say - yes
but probably they own a composite-material factory!!!
so is it really needed…
in the aviation world it is…
in surfboards i’m not so sure!
a very light surfboard may be too loose in the water and only a really good radical surfer
will be able to enjoy its characteristics.
I know that I wouldn’t ! but yet, making things by my own that have the same qualllity of a
factory pruduct and even sometimes better, this is what gives me the rush!
working with a mould is not magic and sometimes requires more time and effort than the old fashion “hand shaping and glassing”.
but I am not a shaper and (still- not for long) don’t know how to design a board by my own,
so copying a proven shape by using the most modern tech known to surfers is , as I see it, a great
improvment .
it seems like u really have a revulsion from “popouts”…
Quote:
Y’know, it’s pretty funny, everyone is up in arms about the molded, “pop-out” surfboard thing, but almost every board has pop-out fins on them…
And fins are one of the most important parts of a boards performance.
Right!
I’ll take it even further, EVERY part of a surfboard is a molded component.
PU blanks are molded.
A finished shaped blank is a single-use male mold for the subsequent laminate.
Popout?
Molded?
That terminology is incorrect IMO.
What people are trying to say, using meaningless buzzwords they heard from their friends, is that it’s NOT CUSTOM.
Molds are about efficiency and repeatable dimensional controls. Use it to your advantage…everyone else has.
Nicely said!
had a though more about my rubber molds
if the rtm transfer is not succesful
was thinking to do it similar to Lees project for the centre
and when the two halves gel
just clamp them together at that stage
----KKsurf.
I understand your point
happens that in the custom orders, I put custom fins always
----Lee_Jordan
“…it seems like u really have a revulsion from “popouts”…”
no, no man
Im trying to figurate out the benefits
nuthin more
----Silly
looking forward to know more about your technique
hey reverb
ive used a bigger template for the mold so i can customize them a bit if necessary
started posting the progress in the compsand thread
Lee, impressive work. Your results with the finished fin are pretty amazing, especially the overall finish quality.
Just playing devil’s advocate here though, in the end all you have is a copy of an FCS G-3000 fin. As you said, a good mould can probably make hundreds of fins. Do you plan to sell these or do you snap alot of fins? What was the overall weight savings of your carbon fins vs. the original FCS ones?
I understand alot of the times, projects like are just as rewarding for the experience and knowledge gained, but it seems lost just duplicating a mass-produced fin.
I’m not really sure what I’m trying to say here, but I am impressed to see the quality of work that you did on these fins but at the same time bummed to see it wasted on copying an average fin.
I guess it’s alot of work to put into prototyping fins though. Probably easier to just grind out glass panel to play with templates and foil, then mold it in carbon once you find something you like.
thanks :-*
u guys give me tons of motivation with your responds.
I have no plan for mass production right now.
ofcourse when I will, it won’t be a FCS copy since it’s illigal to steal their design.
franklly, the fin that I used as my master, isn’t an original FCS.
it’s a perfect fcs duplicate made by a small manufactorer , he sell them for a lower price.
this was my first attempt to make molded parts for surfboards and there was no reason to
get crazy on this one.
when it’ll be time, I’ll mold some other, maybe more proffesional foiled fins.
as I said earlier in the thread, the original fcs weigh 60grams, molded carbon fins can get as light as 15 gram.
mine are 32 grams . next set of fins will be filled with PU and not with thin Microbaloon slurry.
it will make them around 15 grams (maybe less).
next time I’ll be in a surfshop, I’ll weigh the original G-3000 carbon fins.
just for the record- I think they use PE resin in their fins! YUKKKKKK!!! UGH!!!
see ya’ in tha water dude…( I’m getting it…aint I ? )