Noisy fins!!

[WANDERER]

How do you stop fins from humming? both of my new boards do it and I'm positive that a humming fin is a dragging fin. Any ideas?

[Longboarder]

haha my mini mal i had a few yrs ago hummed, it only happened as the board got older so i cant explain why it does it or how to fix it. I reckon if both boards do it and u bought them off the same shaper then it has something to do with there placement and bottom shape of the board. 2 bad both boards huh lol i use to enjoy the noise sometimes it was a nice hum if you ask me

[WANDERER]

It is a nice hum, but it is the noise of lost speed and drag!

[the kalakau kid]

Humming fins are mysterious things but heres a couple of reasons that I've worked out which you might be able to do something about.

1) A bead of resin or piece of plastic somewhere on the foil that is interfering with the fins flow through water.

2) Space under the fins ( if removable) that is allowing water to pass through. Gotta eliminate the space.

3) Incorrrect alignment. This is tough to fix without ripping the buggers out. Use a set square to see if they are straight. This is not simple due to things like Veee bottoms & canting etc but you might see that one is really out of whack.

3) A twist in the fin. Rare but sometimes duds make it out of factories. Look up close & you'll see.

hope this helps.

tkk

[Lard Lad]

1234

[the kalakau kid]

now that is a sad tale mate. I guess you have moved on from occy straps now? Theres a reason why those webbing straps are so popular with truckies - they don't snap!

feeling for you with that one.

[buzzy]

My very first custom board my fins hummed. In that case it was saused by misaligned fins.

Put me off custom boards for 15 years.

[platty]

Wanderer, Check the trailing edges. Whenever I've had humming fins it has always been a bead of resin on the trailing edge. As for lost speed and drag, I think it would be negligible.platty.


TKK, The kettle is allways ready to put on. The MP is still collecting dust. platty.

[Longygrom]

I have the same fin problem with an old single fin and i found out it was because of some fibreglass on the fin.

[Troy_Cisco_Kid]

Could anyone measure the loss of speed it would cause ?

Probably doesn't give a shit of difference to us type surfers.
I had a boad that didn't it to, my first home made longboard...i reckoned it was kinda cool ....

[Bigpete]

Used to happen a lot in the early sixties when we used plywood for fins. One coolite board I remember riding at City Beach in WA really sung. If you cranked a hard turn it howled.
A sharp or damaged leading edge is the usual culprit. Judicious application of #120 wet and dry usually fixes it.
I wouldn't fix it though. Those sort of individual idiosyncrasies are nice in a board