Standup Zone Forum

Stand Up Paddle => Downwind and Racing => Topic started by: mastman on September 18, 2018, 06:21:21 PM

Title: Paddle Blade Coatings for a Race?
Post by: mastman on September 18, 2018, 06:21:21 PM
So obviously putting a teflon or other slippery coating on your race board is fast, but what about the paddle?  Does it make any sense to coat a paddle?

I have no engineering background at all so this is probably a dumb question.  My uneducated thought is that, no, you do not want to make your paddle blade more slippery.  Any advantage you would get in sliding the paddle in and out of the water would be lost when you are powering through the stroke as the paddle would be more included to feather side-to-side. Do I have that basically right?  Does anyone apply coatings to their paddle blades?
Title: Re: Paddle Blade Coatings for a Race?
Post by: Quickbeam on September 18, 2018, 06:58:07 PM
I can’t answer your question about paddle blades, but I believe your assumption that putting a “slippery coat” on your board will make it faster may be incorrect. I remember reading somewhere that it is actually the opposite and that in fact a rougher surface on your board will make it faster. I believe the “Board Lady” had some information on her website to this effect. I think it was something about the water sticking more to a smooth surface and actually slowing you down.

I’m not entirely sure on this as I’m going from memory. Hopefully someone else will chime in.
Title: Re: Paddle Blade Coatings for a Race?
Post by: Quickbeam on September 18, 2018, 07:19:03 PM
More on this from the Board Lady:

https://boardlady.com/fast.htm


Title: Re: Paddle Blade Coatings for a Race?
Post by: SaMoSUP on September 18, 2018, 08:13:59 PM
You can try Onit Pro on your blade...

https://www.onitpro.com/xtreme-cream-blue-goo.html

The paddle wax works good on the shaft when your hands get slick from applying sunblock.
Title: Re: Paddle Blade Coatings for a Race?
Post by: PonoBill on September 18, 2018, 08:36:25 PM
No, and no. Putting gook on your raceboard will make a little money for someone else, no matter how much the true believers may howl. I've tested it, nothing, and I mean nothing I tested does a damned thing. I don't care what the seat of your pants, your Garmin, or your uncle the sailboat god says, it's holy water.

Eva is a smart lady, and yes, it's been known for many decades, from back when lots of engineering colleges had test tanks and boat performance was critically important that a matte surface had less drag than a polished one. I can see the difference between a polished bottom and the same board with the bottom sanded to a matte finish with fine sandpaper at my personal test tank: A section of the Hood River below the old hydro dam that runs straight for some distance. With a windsurfing mast, a load cell, and a dragline I used to test a lot of stuff there.

One year OnIt Pro gave me a bunch of their stuff to test. I did that and some magic goop that a guy who posted here long ago claimed was "known" by all the fast yachties to be substantially faster, and anyone who doubted that was simply stupid. I tested it along with Onit Pro. Nada. In fact, I could say both were slower, but the 1 percent or so slower is certainly in the error band. Sanding is faster--barely. About 4 percent less drag on average.

Now, where were we? Oh yeah, paddles. It would be cool if we could generate some lift, like a wing paddle does for Kayaks, but other than that, more holy water. Quickblade did some golf ball dimples for a while. I guess that finally embarrassed them and they quit. The best thing that can happen to a paddle is for the water to stick to it like glue and refuse to slip across the face.
Title: Re: Paddle Blade Coatings for a Race?
Post by: TallDude on September 18, 2018, 10:29:56 PM
The other end of the paddle is more important in a race. If your hands slip while your in a race, that's not good.
Title: Re: Paddle Blade Coatings for a Race?
Post by: ukgm on September 19, 2018, 12:04:02 AM
1) With a windsurfing mast, a load cell, and a dragline I used to test a lot of stuff there.

2) Sanding is faster--barely. About 4 percent less drag on average.

3) Quickblade did some golf ball dimples for a while. I guess that finally embarrassed them and they quit.

1) That's pretty much how its been done in the research papers when in the field too. i.e. Speedboat moving at a constant velocity with a lateral boom and then kayaks strung behind that clear of the wake and with a load cell in the cable.

2) If you can't find a reliable difference when tow testing, I'd argue it isn't there. There are other reasons I've mentioned before its worth keeping your hull clean though. These include the build up of a 'scum' line around the waterline which will attract grime and minimising the cross contamination of water sources of bacteria. The solution in these case ? - soapy water.

3) I've seen this with a few brands over the years (we had it with cycling helmets). It's a complete misunderstanding of how such a pattern works. Unless people are going to be twirling their paddles like a cheerleader or majorette (and at a very high speed), the dimple pattern will do absolutely squat.

The only caveat to all of this (is that with respect to nature and natural selection), is that sharks developed a course skin and their velocity isn't that much different to SUP's. Therefore, was this development with respect to speed or something else ? (plus dolphin's did not develop the same).

I'm certainly be tempted to test this and find out but like you, I already know what the answer probably is. It certainly won't be statistically significant as my own field testing sees a typical coefficient of data variation of 3% but that's still so great that it would like swamp the results of any special coatings.
Title: Re: Paddle Blade Coatings for a Race?
Post by: SaMoSUP on September 19, 2018, 12:20:23 AM
Yeah so why does my car run faster and get better MPG after I wash and wax it??
Title: Re: Paddle Blade Coatings for a Race?
Post by: ukgm on September 19, 2018, 01:27:32 AM
Yeah so why does my car run faster and get better MPG after I wash and wax it??

Because its moving at a much higher speed. Air resistance rises exponentially so reducing drag becomes increasingly critical the faster you go. For example, it takes you twice as much power to move a bicycle at 30mph as it does at 20mph. SUP's are so slow when moving through water, the fluid flow conditions they are facing are radically different to a car.
Title: Re: Paddle Blade Coatings for a Race?
Post by: ukgm on September 19, 2018, 02:28:14 AM
More on this from the Board Lady:

https://boardlady.com/fast.htm

Again, a windsurfing board is moving at a complete different speed so the fluid conditions won't be comparable to that of a SUP. There's the possibility of hell of a lot of placebo in that write up (or for the nerds interested, the 'Reynolds number' is different between these cases).
Title: Re: Paddle Blade Coatings for a Race?
Post by: yugi on September 19, 2018, 03:19:17 AM
I can’t answer your question about paddle blades, but I believe your assumption that putting a “slippery coat” on your board will make it faster may be incorrect. I remember reading somewhere that it is actually the opposite and that in fact a rougher surface on your board will make it faster. I believe the “Board Lady” had some information on her website to this effect. I think it was something about the water sticking more to a smooth surface and actually slowing you down.

I’m not entirely sure on this as I’m going from memory. Hopefully someone else will chime in.

...
it's been known for many decades, from back when lots of engineering colleges had test tanks and boat performance was critically important that a matte surface had less drag than a polished one.
...
 Sanding is faster--barely. About 4 percent less drag on average.
...

Yep.

A polished or hydrophobic surface such as teflon would give you bubbles along the surface which is turbulence and slows you down. The idea of a sanded surface is that a thin film of water clings to the board surface and water on water is the least drag.

Google boundary layer theory in fluid mechanics

Hull speed perfection is sought after in yacht racing. I went from yacht racing to windsurf racing. In board sports in general the rider skill outweighs any surface imperfections so much that you'll notice that racers aren't anal at all about their boards. The fact that a yacht costs thousands of times more than a board has a lot to do with it.

In 2010 America's Cup (AC33) Oracle Team USA's trimaran USA-17 had some really fancy "friction reduction system" boundary layers fluids going on in it's ama's.

http://forums.sailinganarchy.com/index.php?/topic/102723-usa-17-friction-reduction-system/

You do want to keep your blade and fin edges free from dings and nicks however. That makes a difference.

Of course keeping your board clean does help. And there-in is a tossup. If you wet sand your board for the ideal surface you also create a slight rough surface for shit to grow on. So you need to clean it a lot more than if it was polished.

Which also begs the question to tape up the exposed fin slot or not. I'm lazy and have grey hair and ride a DW board and I also like Larry Alisons take on the fin slot not needing to be taped up. So I don't.

The other end of the paddle is more important in a race. If your hands slip while your in a race, that's not good.

Yep.

And the technique of the owner of the hands even more.

Fitness helps too just BTW.
 8)
Title: Re: Paddle Blade Coatings for a Race?
Post by: stoneaxe on September 19, 2018, 06:20:41 AM
I've heard that magnetic copper hologram bracelets can add power to my stroke and make the waters part before me.....do they work...?
Title: Re: Paddle Blade Coatings for a Race?
Post by: ukgm on September 19, 2018, 06:52:34 AM

In 2010 America's Cup (AC33) Oracle Team USA's trimaran USA-17 had some really fancy "friction reduction system" boundary layers fluids going on in it's ama's.


Coincidentally, I'd also been told about a special coating that Sir Ben Ainslie's last America's Cup campaign was using via a couple of friends I had that worked for the team. I inquired but it was ludicrously expensive (gold was cheaper !) for even just a small amount, (let alone it wasn't easy to lay hands on either).
Title: Re: Paddle Blade Coatings for a Race?
Post by: yugi on September 19, 2018, 08:21:07 AM
I've heard that magnetic copper hologram bracelets can add power to my stroke and make the waters part before me.....do they work...?

I wore one of those hologram bracelets on a night I spent with a Venezuelan hottie. Oh yeah. Works like crazy.
Title: Re: Paddle Blade Coatings for a Race?
Post by: Kwolfe on September 19, 2018, 08:55:58 AM
From Greg Barton himself (olympic K1 paddler and co owner of Epic):

“I’ve only seen two things (so far) that make a significant difference in speed – and both have been banned by the International Canoe Federation for racing. The first is a slimy polymer compound applied to the surface of the boat. This compound dissolves in the water, lowering the viscosity of the water next to the hull and reducing drag. As it dissolves it comes off until it is no longer effective (leaving contaminated water in your wake)…The other item that really works is a “riblet” material manufactured by 3M. It is an adhesive backed plastic film with very fine grooves machined into it (similar to the grooves in a phonograph record). The size of the grooves is matched to the density of the fluid (water in our case) and the speed of travel so that the grooves dampen the turbulence of the water as the flow detaches from the hull.”
Title: Re: Paddle Blade Coatings for a Race?
Post by: ukgm on September 19, 2018, 09:43:29 AM
The size of the grooves is matched to the density of the fluid (water in our case) and the speed of travel so that the grooves dampen the turbulence of the water as the flow detaches from the hull.”

Absolutely. ..... and this is for watercraft that are typically operating at 13-15kph. SUP's are lucky to get to 10 so you can imagine how relevant that probably isn't when compared to other factors at that point (such as addressing theoretical maximum hull speed).

Note: We use 'trips' and changes in surface texture on our skinsuits in cycling now to do the same thing. I've got a time trial suit designed for 40kph and another for circa 40kph that I use (depending on the kinds of courses I might be racing over..)
Title: Re: Paddle Blade Coatings for a Race?
Post by: PonoBill on September 19, 2018, 05:44:45 PM
Dolphins have tiny lateral grooves in their skin that vibrate with muscle movement to mitigate wall drag. Sharks do a similar thing with their denticles, which are a lot more prominent. Dolphin skin also seems to shed bacteria and fungus by its microstructure. Nothing much grows on a dolphin.
Title: Re: Paddle Blade Coatings for a Race?
Post by: Pierre on October 01, 2018, 03:52:50 AM
Boundry layer, also called limit layer, laminar, turbulent, means a lot... purpose is to get it as thin as possible.. on a paddle blade I guess purpose is NOT to take water out with it.
on a hull, 400 to 500 sand paper... many other solutions here...and finally!!!   https://www.gp14.org/a-smooth-bottom-is-a-fast-bottom/
Title: Re: Paddle Blade Coatings for a Race?
Post by: yugi on October 01, 2018, 08:26:03 AM
^ Yep.

The article’s conclusion is spot on:
“In the end, it’s not that complicated. Your appendages should be as smooth and fair as possible, and your hull should be just as flawless in the forward areas. Aft of where you expect transition on the hull (certainly by amidships), the surfaces need only be “hydrodynamically smooth.” Finally, when faced with the myths, remember the no-slip condition.”

Thanks for the link, Pierre. Fun, because I was at Brown with Paul Grimes but no longer sailing undergrad regattas.

After that I was mostly in board sailing (and traction) sports. Where I quickly learned first-hand that when planeing no one cares about the “boundary layer” on their boards.

More relevant at our (SUP) speeds, but still technique, ability and fitness still count so much more that it’s practically irrelevant.
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