Contact   Imprint   Advertising   Guidelines

Foil sanding to get rid of turbulence

A forum dedicated to Hydrofoil riders
rnelias
Very Frequent Poster
Posts: 1133
Joined: Mon Sep 16, 2019 11:07 pm
Local Beach: RJ, Brazil
Favorite Beaches: Arubinha, RJ
Cumbuco, CE
Barra da Tijuca, RJ
Praia da Bica, RJ
Style: freeride
Gear: Boxer 9m for foiling
Rebel SLS 8m or Crave HL 9m for boosting on twintip
Brand Affiliation: None
Has thanked: 290 times
Been thanked: 269 times

Re: Foil sanding to get rid of turbulence

Postby rnelias » Sat Jun 04, 2022 4:25 pm

Matty V wrote:
Sat Jun 04, 2022 4:05 pm
Yacht rudder and keel design.. brilliant

This is why the internet is stupid. A normal yacht with a keel operates in a 6-12 kt speed range.

Our kite foils are a magnitude thinner in profile and operate at speeds 3-4 times that of the article.

Think before you sand
until someone devote time to research and publish data specifically about kite foils, it's the best we have on this subject, otherwise, we can only rely on our perception about complex physics related to wings and foils. The book only discusses how the TE finish affects the flow pattern. When I had problems with a home made stab whristling I carefully sanded the TE with #7 profile and it worked fine, but it's not the original question -- draggy perception at low speed -- and I think you, @Matty V, pointed out something to be checked before. Screws and bad parts fit seem to be a better bet in this case :wink:

User avatar
Kamikuza
Very Frequent Poster
Posts: 7057
Joined: Fri Jan 09, 2009 4:49 am
Local Beach: Sabae Beach
Favorite Beaches: Ol' Stinky
Gear: This, that, the other
Has thanked: 220 times
Been thanked: 193 times

Re: Foil sanding to get rid of turbulence

Postby Kamikuza » Sun Jun 05, 2022 11:25 am

Matty V wrote:
Fri Jun 03, 2022 9:18 am
99.9% of the time where surface finish is concerned you will make it worse.
That's a bit pessimistic.

I was anti the effort involved to supposedly make things better, filling the holes and whatnot. Turns out, all you need to do to overcome the lumpy feeling from scuffs and scratches is run some 1000 grit wet gently over the surface. Run the water on it and let it "dry" --the water should come off uniformly, without clearing from spots in the middle, if you get me. Gently square the TE and you're done. Should feel silky smooth under foot again.

andylc
Very Frequent Poster
Posts: 1175
Joined: Fri Apr 07, 2017 3:26 pm
Local Beach: Exmouth
Favorite Beaches: Saunton Sands
Gear: Reedin Supermodel V3 7,9,11m, Duotone Juice 13m
Saul Custom Wave Board 138cm
Nomad Superleggera LW 142cm
Brand Affiliation: None
Has thanked: 2 times
Been thanked: 139 times

Re: Foil sanding to get rid of turbulence

Postby andylc » Sun Jun 05, 2022 11:51 am

Not tried it with a foil but sanding carbon fibre isn’t that difficult - just wet sand with coarse enough grade to get rid of marks and then keep going down to about 2000 grade before buffing. I have filled small deficits with black Milliput in other situations (carbon fibre mountain bike crank) which worked well.


Return to “Hydrofoil”

Who is online

Users browsing this forum: Brent NKB and 67 guests

cron