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[AlanP]

Just a quickie, does it make any difference polishing the bottom of the hull on a fast electric boat?
 
Alan

[Mad_Mike]

Its deemed a bad idea to polish propellers as it increases surface tension of the water passing over the blade. A rough surface gets air bubbles on it which act as a lubricant between the water flow and the surface. So i can only presume then that a polished hull would have the same affect.
Im probably wrong though

[Stavros]

I allways give my 1 mtr Yacht some polish as I find it does make a difference.Think about it when you polish a car the water will globulate and simply fall off the car,with no polish on it the water simply sticks to the paintwork,so if I am right a polished hull will go faster.Another thought is winter sports why do skiers and snowboarders wax the ski's and boards...........simples really to make them go faster.......I rest my case My lord..................I THINK !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


Dave

[john44]

Surfers spend hours waxing their boards, I T-cut lightly and re-wax
/ polish my IOM if it feels at all flat or gritty, a scum line tends to
 form on the hull after a while and that really slows the yachts down.
So I presume the same goes for fast power boats.

john

[AlanP]

So, up till now that's two for polish and one against 

[derekwarner]

  in OZ...surfers wax the top of their boards to make it a tacky surface .......so their feet don't slip off  ....nothing to do with speed ....Derek....without a surfboard.....

[john44]

Well Derek, I can,t hold a candle to that reply.

john

[eddiesolo]

I have some plastic polish I use on the car, it is expensive and the stuff that the MOD use. It comes in a small grey bottle, very good stuff and gives a lovely smooth finish.




Si:)

[Guy Bagley]

so why doesnt my car go faster when its polished then  ?......

[Netleyned]

You need Polish petrol or diesel

Ned

[knoby]

Class 1 offshore powerboat thinking is that a matt hull is faster, they tend to wet flat their hulls rather than polish them, for much the same reason as Mad Mike stated for prop thinking. However in recent times a USA Company has produced a high gloss polish that many are now using instead. The 'Shark suit' used for a while in swimming was considered such an advantage that it was banned, but each year the swimmers still break records without using it now.
I doubt very much that it matters what kind of hull finish a model has, as the amount of it in the water is so slight, the main thing is you keep it as clean & smooth as possible. Personally I wax all my hulls, both power & sail, just so they look good.

[sparkey]

  Whatever you do don't polish your boat every time I polish the car it rains,Ray.

[john44]

Yes but without rain we would have no pools to sail our boats in.

john

[sparkey]

  Good point John,Ray

[Mad_Mike]

I allways give my 1 mtr Yacht some polish as I find it does make a difference.Think about it when you polish a car the water will globulate and simply fall off the car,with no polish on it the water simply sticks to the paintwork,so if I am right a polished hull will go faster.Another thought is winter sports why do skiers and snowboarders wax the ski's and boards...........simples really to make them go faster.......I rest my case My lord..................I THINK !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


Dave

the globulating water is caused by the surface tension which causes drag. The rough surface gets air bubbles in it which act as a barrier and reduce the surface tension but this is at high speed. Skiers and snowboarders polish there gear because the snow doesnt create bubbles when its cut at speed like water does. Even if snow does create bubbles it wont be to the same extent as water.
As knoby says and i agree polish or no polish at scale size the speed difference would be largely unoticeable.

[AlanP]

Right, I have taken on board all the comments, constructive and otherwise  and decided to go for the polished look, as knoby says, it will look good. As the buoys on our lake have fibre glass magnets in them it may help the boat slide over them easier, some say it is my steering skills that are to blame, not the magnets 
Alan

[pompebled]

Hi Alan,

Mike is correct, a mat surface (600 grid, sanded wet) makes a waterfilm cling to the surface, making the boat quicker.

I once tested this with two identical speedboats; one waxed, and one sanded wet with 600 grid.

We swapped all components between the two boats, motor, batteries, props, to eliminate one component being faster.
Endresult: the waxed boat always lost out, the sanded hull was quicker, in acceleration and in topspeed.

Needless to say all my competition boats are sanded and yes, they pick up dirt more than a smooth hull, but we clean them prior to every run.

Regards, Jan.

[AlanP]

Thanks for that Jan, was there much difference?
 
Alan

[martno1fan]

Surfers spend hours waxing their boards, I T-cut lightly and re-wax
/ polish my IOM if it feels at all flat or gritty, a scum line tends to
 form on the hull after a while and that really slows the yachts down.
So I presume the same goes for fast power boats.

john

Surfers wax there boards to help them stick to the water  .
Most racers actually wet sand there boats bottoms this creates tiny air bubbles and stops the boat sticking to the water thus makes them run faster.Mercury marine for instance leave there props with a duller finish for the same reason.
You can also buy special paints and coatings to spray on your boats bottom that disperse the water faster thus making the boat run faster.
Don't wax the bottom save that for above the water  .
Mart

[john44]

Thanks for that info guys, it just goes to show you,r never too old to learn.
I will sand my hull down with 600 wet and see if there is any difference
when sailing my Cockatoo IOM.

john

PS if it doesn,t it,l be in the sales posting.

[pompebled]

Thanks for that Jan, was there much difference? Alan

Hi Alan,

Racing around a 30 x 30 x 30 m course with just two boats, the difference was sufficient to lose a place every ten laps or so.
Given the fact that we ran about 30+ laps in the 7 minute heat, this was enough to drop significantly in the overall results, specially as there were more than 2 boats at the start (usually 4-6 boats).

Regards, Jan.

[pompebled]

Thanks for that info guys, it just goes to show you,r never too old to learn.
I will sand my hull down with 600 wet and see if there is any difference
when sailing my Cockatoo IOM. john
PS if it doesn,t it,l be in the sales posting.

Hi John,

A sailboat is too slow to be able to see the speed difference between a smoothly dull sanded and a waxed hull.
Here it's more the set-up and the man/woman at the sticks that will make the difference...

Regards, Jan.

[martno1fan]

Hey Jan you may have seen this but this product might be worth a try,i know a few guys have used Teflon type spray paint also which seems to work.
Mart
ps this stuff would be great to protect electronics against water and also hardware against corrosion and dirt.
http://www.break.com/video/can-this-product-really-keep-liquids-out-of-everything-2464694

[john44]

Hi John,

A sailboat is too slow to be able to see the speed difference between a smoothly dull sanded and a waxed hull.
Here it's more the set-up and the man/woman at the sticks that will make the difference...

Regards, Jan.

Jan you have found me out, I was all for blaming the paint finish for my
performance in the yacht racing events at our club waters.
I,ll have to think up another reason now. 

john

[boatmadman]

Now you know why I was thinking of a matt or satin finish!