given two idential shapes, which is faster through the water? (sorry if this has been discussed before).
Your board won’t go fast enough to benefit from either a textured or gloss surface. I remember Jim Phillips posting some info. from an Navy/Coast Guard report to this effect. It comes down to asthetics.
I take my recommendations from the billionares that build and design 12-meter or America’s Cup boats that have to perform at similar speeds…the shinier the better.
I take my recommendations from the billionares that build and design > 12-meter or America’s Cup boats that have to perform at similar > speeds…the shinier the better. …I prefer (for myself)a fine sanded surface with a thin,speed-sanded,acrylic wash on my bottoms,and rails(I could care less about the deck).The acrylic surface is faster/looser than a resin surface.After I surface a board like this, I have a hard time duck-diving my boards, because they are so slick they’re hard to hold onto.Herb
given two idential shapes, which is faster through the water?>>> (sorry if this has been discussed before). Sanded is faster. Think about an un waxed, glossed and polished longboard, you can stand up on it without slipping because it will not hold water against the surface like a sanded finish. Sailboards use sanded. Sharks have dermal skin for the same reason. Water on water is fast. The big question is the level that you will notice it in the surf. If speed is the issue, I would look to knock a little rocker out of the blank, or maybe a little bit harder rail. That’s where you can seriously talk about speed in the design formula. I tried an experiment a few years back. Put a gloss and polish on the front 1/3rd of a board with a sanded finish in the back. My theory was that the board would drive into a turn harder by making the tail of the board faster across the water (remember, the tail has to travel a further distance in a turn than the nose). It seamed to make a difference. Or was it just the placebo effect? Maybe I’m just board. Shine
Those 12 meter teams spend millions of dollars every year checking out hull treatments that will gain them a thousandth of a meter/sec. Not one of those boats has a sanded finish. The old theory of laminar flow turns out to be incorrect. You know, that’s the one where water molecules form sheets so by having these microscopic pits in a surface would make things turbulent enough to keep the sheets from grabbing the surface and slowing things down. Well in fact, water molecules form strings and the strings just love to grab onto little pits hence slowing things down. Probably the weirdest surface was the one tried by Morey back in the seventies. Crush up some Alka Seltzer into your hot coat, paint it on (you have to keep the bottom out of the water 'til the last second). Jump on a wave and you glide on a cushion of carbon dioxide… Newbs
Those 12 meter teams spend millions of dollars every year checking out > hull treatments that will gain them a thousandth of a meter/sec. Not one > of those boats has a sanded finish. The old theory of laminar flow turns > out to be incorrect. You know, that’s the one where water molecules form > sheets so by having these microscopic pits in a surface would make things > turbulent enough to keep the sheets from grabbing the surface and slowing > things down. Well in fact, water molecules form strings and the strings > just love to grab onto little pits hence slowing things down.>>> Probably the weirdest surface was the one tried by Morey back in the > seventies. Crush up some Alka Seltzer into your hot coat, paint it on (you > have to keep the bottom out of the water 'til the last second). Jump on a > wave and you glide on a cushion of carbon dioxide…>>> Newbs --------------I tend to agree, after working on boats for a few years none of the hulls I (we) did was the hull left sanded . I personally love the feel of a 400-600 grit sanded finished board but I don’t for a moment think they are any faster–I’ve done my own research EC,WC,& Hawaii but have of yet to come up w/any concrete evidence that makes me believe a sanded is faster than a gloss.And since you brought up the alka seltzer thing remember the spray teflon coating stuff or Steve Walden’s peel and stick vinyl coating on the bottoms.
What really sold me wasn’t the theories…it was finger prints! Those sanded finishes always got so dirty after a while. That meant that you’d have to sand off the schmooze constantly to keep that flow clean. If schmooze and boogers stuck what was the point? Hell, what about the slots you put your fins in, or the screw that sits up like a little bullet right in front of the leading edge of the fin. Oy and what about your leash hanging off the tail or your toes hanging off the rail. The first response to this thread was right…you’ll never be able to tell. (but its fun thinking about it!) Newbs
specifically, the trailing edge of the slot on a long box always seemed like it could catch the water flowing around the base of the fin and act like a brake. I’ve been known to take a rat tail file and take the corner off that back edge of the slot. Did it work? I don’t know - but it made sense at the time!
Back in April of this year, I wrote: "In all my boards that involved a hard resin or epoxy finish on the bottom, rails and fin(s), that #320 wet/dry, parallel to the centerline was the exact combo for performance and FEEL. When wet, it wasnt as much slippery, as it was sort of "directionally slimey"... that water would just sheet out cleanly." Although I cant personally quantify higher speeds, running surfaces which retain a very thin film of water, as opposed to a beaded high gloss finish, have always seemed to perform and feel better (to me). Plus, Im not convinced that its accurate or productive to closely compare racing sailboats and surfcraft… aside from the obvious differences, there are many other significant factors relating to choppy open ocean surfaces vs. all that`s occurring on (and inside) the body and curves of a wave. Dale