i dont really know all that much but...
Slalom fins are really hard to turn into freestyle fins due to the thickness... and it would take forever to sand it down.
Really at the end of the day, you can use ANY type of fin to turn it into a freestyle fin. Gollito grabs any fin cuts it using a circular saw and then goes sailing on it...
Having a fin that is 24cm, makes freestyle quite hard, all the boys that i have spoken to use fins from 20cm and under?
Hope It Helps!
CHEERS!
white water samba mundial 20 or a MFC freestyle 20. 24 is way to big for freestyle no mater how experienced.
so what does a freestyle fin look like ... like a wave but with out that curver that stick out the back?...and so so small that u can easily spin out in sertainnamouvers but still hold grip for others?
cheers guys,
looking for a 24-25cm fin, don't have what it takes to get the small freestyle fins going.
unfortunately my 25cm mfc freestyle pro fell out of my board yesterday after i didn't screw it in properly so i need a new one.
i liked the freestyle pro very much, it had excellent early planing, went upwind and carved well, only downside was it's top end speed which you hit in about 50m.
looking at the new mfc goya freestyle but having trouble finding one. 
lanky have you tried the white water freestyle MX?
Yea tried both the freestyle MX and the samba. decided to go with the samba 18cm on my board but a fried of mine has the samba 22 or 24 can't remember exactly and loves it. I think he uses it it both his freestyle wave 92 and 106lt
cheers again guys,
hi mark,
mk over here has made some cracker fins using the method you describe. he hits them with the grinder and then cleans them up by hand.
^ agree mate,
but without seeing one i'm just not sure. plus they have a 4 week turn around. i need another fin asap to get back on the freestyle wagon. only other fin i have for the board is a 32cm freewave.
edit* wanted to mention the freestyle pro i lost is not the new shape, it's the older white one.
cut something to around 20cm, any longer and it would catch a little to much.. u should be able to get used to sailing with a smaller fin by keeping your weight way way forward (also way more catapults) and eventually it will feel normal again.. it should improve your speed and normal sailing by gettin used to sailing small fins..
with a grinder it wont take long.. make any shape u want but a little bit of a bendy wave-like tip cant hurt.. my current fin was about 30cm and i cut it down with a hacksaw and used a brick for the sanding, its 15cm.. make life easy by gettin some good sandpaper
cheers barn,
awesome vid by the way. seeing what you are doing with a fin cut with a hacksaw brings a lot of perspective to things. 
edit.... as everyone has suggested above i'll go for 20cm.
Brainstorm: Sharper rails, like heeeeaps?
Kites get away with much more power and tiny, wee little fins.
