SMOOTH enough ?

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wouter's picture
Joined: 04/23/2004

Dear all,

When is a board SMOOTH enough?

Do you stop at 320 grit and know from experience that the board-bottom is SMOOTH enough to surf it ?
Or, did you rather take the whole process a step further and fine sand it to a 1000 Grit, after which you took out the Polisher and polished it till 10.000 grit, till you found the board to be REAL smooth.

WHAT is the difference in the skimming [surfing] properties of the surfboard with a real real smooth surface and a seemingly smooth surface?
From boat-builders in my country I heard saying that the competition sailers do not want a perfect smooth boat-bottom. For then the bottom and the water stick together better [something called adhesion ?] ==> more resistance for the boat to go through the water.

Anybody did experiments?

Bye U-all, happy writings.


ambrose's picture
Joined: 03/18/2004

Smoother =burn through potntial accelerates to likely reality...a good gloss dont need much ....if you need a place to shave keep polishing till you can see yourself clearly....polish is another way to make up for a less than successful gloss...I think a good rub out happens a month or two after the gloss goes off - its harder and must take the polish polish deck stronger polish go surfing quicker... When I picked up Lockwoods board that was a year old that the rail still had that hard edge of the gloss tape still there ...smooth is smooth enough but its not smoothe..polish freaking is a captivating pursuit , its fun sometimes and then you get with a card carryin' polish critic and you can really find out how far you can go on the polish trail...ambrose...I can always see the flaws when I quit...


ambrose M. curry III

wildy's picture
Joined: 03/19/2004

Polishing does seem to be a dying art, the spray matt finish era took it's toll on new boardmakers developing the skill.

I sprayed a few boards years ago with some sort of two pack urethane gloss paint and got a great finish, with no extra work. There were a lot of guys who had never seen a shiny board and then wanted them. I read in here that many others are spraying gloss with success.

Although feeling slicker, the shiny smooth bottom is not the fastest. The adhesion you mentioned creates a larger boundary layer, which although giving you grip, is not as fast.

I wanted to try and reduce the boundary layer, so I did a first hand experiment with this by leaving the bottom rough. I sweegeed the filler to leave the weave, like textured decks used to be, then sanded where I wanted grip. I sanded the rails and edges, and probably half inch of the bottom under the rails. Fins were smooth of course.

The board went great, fast, smooth, nothing ballistic. Till I refilled the bottom and sanded it smooth. Then I felt the resistance the smooth bottom created. The board still went really well, just didn't feel quite as free.

I've heard about some stick on stuff used in high perfermance yachts to reduce surface tension. Anyone know about it or tried it?

LeeDD's picture
Joined: 03/18/2004

Windsurfers always try all the different goopy slick stuff, and in the end, it just barely makes the speed the same. Going sideways, spinning out, taking longer to achieve planing, all offsets whatever top speeds it can give, besides wear out unevenly, in patches, causing irregular planing ability on different parts of the board.
Wouters, fastest so far anyone can find is sanded 400 IN THE DIRECTION of water flow.
Makes no difference in surfing, as speed is important only 20% of the time.
Most of the time in surfing, you are going very slow, or barely planing, or turning.

gregloehr's picture
Joined: 03/22/2004

Try 400 wet and dry like Wildly suggested and you'll feel the difference. Taking the gloss off definitly make the board freer. Lee is right too. Accelleration is more important in surfboards than speed.

meecrafty's picture
Joined: 03/20/2004

There are clear spray on products for boat hulls that keep the surface wet...
Hydrophillic coatings. It's basically the opposite of car wax (hydrophobic).
They are not cheap and may not make a significant
difference due to surfing's low speeds and the relatively small planning area (as compared to boat hulls) but I use them anyway. Using crude water hose testing, water runs off the board easier. One issue though...after waxing the top of the board and carrying it, the wax residue from the hands always contaminates the bottom/rail.

SMOOTH enough ? | Swaylocks
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