DavidJohn said...

I think you're right.. (the topic title bit)..

DJ

make it bullet proof or at least dy point proof

Piros said...

This will probably start the argument again of polished finish v Protect , it all comes down to surface tension. Aircraft are nice and shiny for maximum slip but water grabs and sticks , so you need to find ways to break the grip of the water , Protect seems to be the answer of roughing up the surface to break the tension but there is no real science of how much texture is to much and when a textured surface actually creates more drag.

MickV said...

I remember going through this stuff when I used to race K1's. All the experimentation ended up showing that only a certain type of minute groove pattern, running in a specific direction proved to be faster than a polished surface. The gains were only marginal but enough to get the grooved material banned.
We tried wet rubbed vs highly polished and in the end there we couldn't prove enough difference to bother with.

I did a similar test when I used to water ski race , the results were dramatic when you are doing 90mph , we first started rubbing the bottom of skies back with 1000 grit wet and dry , you could really feel the difference on the drag on the ski was heaps less. I took it too far and rubbed my ski back with 400 grit for the Hawkesbury river race and after just 5km my legs were blown and it cost us the race.It felt like I had shag pile carpet nailed to the bottom of my ski.

It's alot harder to feel the results at 10 to 15km on a Sup, yachts still use the grooves that MickV tried but thats more channeling the water for straight line running.

In my humble opinion we still haven't found the sweet spot between polished and Protect and Lacey might be onto something........

Rob

MickV said...

I remember going through this stuff when I used to race K1's. All the experimentation ended up showing that only a certain type of minute groove pattern, running in a specific direction proved to be faster than a polished surface. The gains were only marginal but enough to get the grooved material banned.
We tried wet rubbed vs highly polished and in the end there we couldn't prove enough difference to bother with.

MickV said...

Hi Lacey, I stopped racing a long time ago so I don't know what they do now. But back then we tried a few different things and car polish was one of them. There were different theories going around then, various degrees of wet rubbing right through to extreme polishing. There was even a type of acid that you painted on the hull and let dry and when you put it in the water it reacted and made the boat more slippery (never tried this one on a kayak but used it yacht racing years later). In the end I think most just settled on a clean boat.
Mostly I copied some of the stuff that the top guys were trying. Piros the coating with the grooves was used at world champ. level for a while. I think the Americans used it until it was banned. My lack of ability kept me well away from that level.