Gofoil humming problem

[scubasteve]

Hi
Recently bought a gofoil maliko 200 over the moon with the quality.
I have got out on the foil from brand new so no damage,i had one small ride on the foil but she hum's.
Does anybody no the fix for this? Both wings are tight, but the rear only tightens up in the last 4mm, i suspect the rear wing.
Any ideas how to stop it humming?
Thanks
Steve

[Dwight (DW)]

No idea how to fix. Gong foils says it’s normal and can’t be stopped without sharp edges. Lots of “surf” foils hum.

Even foil experts give conflicting advice on how to prevent.

I assumed all surf foils “must” hum because of the rounded safety edges, but then I switched to Naish, and no hum on mine or my friends. So I don’t know shit apparently

[clay]

I know guys who have sanded - ummm if I remember correctly the trailing edges on the tips - don't really remember where.   But anyway they sanded a bit and humming went away.  Maybe try googling it.

My Maliko would hum now and then.

My foil science does not and never has hummed.

[opie]

Small imperfections can cause this or make it worse.  Even a new foil might have some.  My first step on a kite foil is always this.

https://www.youtube.com/watch?v=YsN-2T7zMLM

It is usually the mast, but not always, on kite foils.  I have heard, but never had to try, that sanding the trailing edge of the mast square a tiny bit can help.  This is on sharp kite foils though, not sure if it applies to more rounded surf foil masts.

There are lots of long threads about this on kiteforum.com.

[sharksupper]

Mine all do it (Lift/GoFoil), I figured it's normal.  I don't see any imperfections in the parts at all.  What does it hurt really?

[Dwight (DW)]

Kite foilers go to extremes trying to get rid of hum, but then you look at the thick lumpy Naish stenciling on their wing and it’s silent.

[PonoBill]

I like the hum. If smoothness is the answer then I'm never going to be quiet. I've run mine into too many rocks.

[cnski]

Clay- Can you post some pics of your Foil Science foil at some point? Love seeing new designs. Thanks

[scubasteve]

Interesting responses
Is there any people who have a gofoil that is quiet....?
It would be interesting to see what the ratio is from quiet to noisy.
Noise genrated would be inefficient an have a slight drag effect.
I am just thinking that the trailing edge of the rear wing in the middle where its square is where it is coming from.
I will be able to do some testing next wk when home.

[Sup-position]

I took a file to the trailing edge of my Gofoil Mast
The humming was significantly reduced after that.
At full lift is is silent
at lower lifts and going at an angle to the wave I sometime hear the humming
Going Straighter on the wave it is silent

[DailyBread Surf Photo]

my gofoil doesn't hummm, and it has many deep scrapes in the surface. 

[starman]

This link my help explain the problem as well as a fix.

https://www.windfoilzone.com/single-post/2017/07/13/WHY-IS-MY-FOIL-WHISTLING?fb_comment_id=1537020639689651_1537032623021786

[scubasteve]

Thanks for all the replies.
I have received an email from Alex, explaining what to look for.
He says to
look for rounded surface of the wings trailing edges in the last 1/4 inch. You need to correct this by sanding a concave or straighter release in the last one inch.But put a straight edge on the trailing surface of the last one inch top and bottom and see if you see a rounded direction at the edge.

I will look at mine next week when home.

Top bloke Alex.

Cheers
Scuba

[PonoBill]

I think the reason mine hums is that it doesn't know the words.

I did notice yesterday that when I get the foil higher it stops humming. If I get it too high it starts slurping. Auditory instant help for the ideal position. It's not a bug, it's a feature.

[blueplanetsurf]

I talked to a friend who is a good kite foiler about this.  The humming is not really a problem in itself but it is caused by vibrations which can make the foil function less efficiently.  That's why kite foilers, who operate at much higher speeds than we do on surf foils, will go to great lengths to get rid of humming, usually by wet sanding the tail wing.
If they are testing a new kite foil and can't eliminate humming noises by sanding it, they consider it faulty and will scrap the design.
I don't think that a humming surf foil is a concern and I have heard that some people like the auditory feedback but in the kite foiling world a foil that hums is considered inefficient.  Personally, having experienced both, I prefer the sensation of smooth and quiet flight over a humming noise but have not noticed that humming has any effect on performance.