I know we have talked about this before, but I saw this quote on Bruce Jones’ discussion board. Quote, …“You won’t notice a difference in the gloss vs. sanded finish when it comes to performance. Sail boat racing teams (ie Americas Cup) have spent Millions of dollars on hull surfaces in test tanks (textured vs. super smooth) with no definative results…” So, are the glassers out there trying to make their jobs eaiser, or is a sanded finish faster? SteveA
If you took a sanded finished board, a speed coat (sprayed), and a gloss coated board put them bottom up at an angle and ran water from a hose on to the surfaces one at a time, I think that you will find that water will flow better over the gloss. Does that mean a gloss is faster? I don’t know and I don’t think anyone else can give you a for sure answer. There are so many variables with a board and the ocean. I think it comes down to asthetics and material cost.
I know we have talked about this before, but I saw this quote on Bruce > Jones’ discussion board. Quote, …“You won’t notice a difference in > the gloss vs. sanded finish when it comes to performance. Sail boat racing > teams (ie Americas Cup) have spent Millions of dollars on hull surfaces in > test tanks (textured vs. super smooth) with no definative > results…” So, are the glassers out there trying to make their > jobs eaiser, or is a sanded finish faster? SteveA maybe the difference has to do with a factor of velocity (that cannot be reached by a surfboard or a sailboat); consequently the indifferent results. cool question for us amateur physicists to ponder…any fluid dynamic experts out there? you would think a smoother surface with less inherent surface area would have less friction…
Sanded is faster than gloss. Sanded holds water against water. Here is the test: Stand on an unwaxed sanded board – you fall right off 'cause its slipery when wet. Stand on an unwaxed gloss board – yeah, you can do it – your nubby little toes stick to the slick gloss surface. However, one versus the other will make little noticable difference when surfing. Shine http://users.leading.net/~shine
i remember reading somewhere about airflow over the wing of a plane and how the leading edge was textured like sandpaper. something about “pre-exciting” the air flow and thereby reducing turbulence over the middle and trailing edge. seems if the above post is correct and a sanded board is faster, wouldn’t sanded fins be faster(smoother water flow) as well?..
i remember reading somewhere about airflow over the wing of a plane and > how the leading edge was textured like sandpaper. something about > “pre-exciting” the air flow and thereby reducing turbulence over > the middle and trailing edge. seems if the above post is correct and a > sanded board is faster, wouldn’t sanded fins be faster(smoother water > flow) as well?.. Yes – but remember in all this that at somepoint increasing the texture on a surface will produce drag and turbulance. A boat with barnicals on the hull will not go fast. A plane with frost on the wings will crash. But a shark with a skin textured to about 100 grit will cut through the water like a knife. As for a fin, yes it will be faster. But is that a good thing? May make it more likly to cavitate. Shine http://users.leading.net/~shine
besides making a board look significantly better, does the gloss improve the structural intregrity of a board whatsoever? can the gloss add some extra strength? -steve
besides making a board look significantly better, does the gloss improve > the structural intregrity of a board whatsoever? can the gloss add some > extra strength?>>> -steve …A gloss can add some longivity to a board by sealing it better,but over polishing can also make it weaker.Herb.
maybe the difference has to do with a factor of velocity (that cannot be > reached by a surfboard or a sailboat); consequently the indifferent > results. cool question for us amateur physicists to ponder…any fluid > dynamic experts out there? you would think a smoother surface with less > inherent surface area would have less friction… You’re exactly right in that the velocity achieved with sailboats (or surfboards)renders minute differences unmeasurable. I was involved in a lot of testing of bottoms for IOR sailboats in the 80’s, and even with the displacement of 38 - 48 foot boats you couldn’t measure a difference. In theory the finely sanded surface is faster as it grabs a film of water creating a boundary layer for the moving water to flow against. In practice the difference doesn’t even begin to be measurable when you’re talking small displacements like surfboards.
I know we have talked about this before, but I saw this quote on Bruce > Jones’ discussion board. Quote, …“You won’t notice a difference in > the gloss vs. sanded finish when it comes to performance. Sail boat racing > teams (ie Americas Cup) have spent Millions of dollars on hull surfaces in > test tanks (textured vs. super smooth) with no definative > results…” So, are the glassers out there trying to make their > jobs eaiser, or is a sanded finish faster? SteveA In an article that came out in the 70’S, the U.S. Navy in conjunction with the UC Santa Cruz did tests on laminar flow for naval ships, The resulting data showed that the true laminars boundary didn’t start to happen until 57 knots, way beyond anything of surfboards of todays technology.
besides making a board look significantly better, does the gloss improve > the structural intregrity of a board whatsoever? can the gloss add some > extra strength?>>> -steve Yes a gloss does make a board stronger, not to the point of indestructibility, but like the shell on an egg. Also it is less pourous than sanding resin and more resistant to water creep. Glossing and polishing is a pain for todays disposible short boards, the industry have sugar coated the advantages of sanded finishes and we as consumers, not wanting to seem ignorant have bought right into it. My oldest son is a foot taller than me and insists that he can’t turn a board over 6’6" or that a glossed one is tooooooooo heavy. My own son a sheep!
You’re exactly right in that the velocity achieved with sailboats (or > surfboards)renders minute differences unmeasurable. I was involved in a > lot of testing of bottoms for IOR sailboats in the 80’s, and even with the > displacement of 38 - 48 foot boats you couldn’t measure a difference. In > theory the finely sanded surface is faster as it grabs a film of water > creating a boundary layer for the moving water to flow against. In > practice the difference doesn’t even begin to be measurable when you’re > talking small displacements like surfboards. thanks, an interesting bit of factual info that can be filed away for reference…
In an article that came out in the 70’S, the U.S. Navy in conjunction with > the UC Santa Cruz did tests on laminar flow for naval ships, The resulting > data showed that the true laminars boundary didn’t start to happen until > 57 knots, way beyond anything of surfboards of todays technology. I’ve always gone for the best of both worlds. I get a gloss coat to seal everything up but I don’t polish it, just do the primo wet sand. I feel putting the buffer on a “green” glass job heats the laminate up too much and weakens the bond. Plus I like the “flat” look finish rather than the hard candy, off the rack, mainstream polished finish.
thanks, an interesting bit of factual info that can be filed away for > reference… I’ve found that a last touch with 1500 grit wetdry and a little hand waxing does the the trick for me. A little careful hand work can go a long way.
This is right up my alley since this is what I do for a living. I believe the best finish is a wetsanded gloss. A nice thin gloss coat seals up the board-waterproofing it. I know “sanded finishes”(or sanded unfinished in my opinion) are the norm and most surfers order this in order to save a little weight. All my boards are glossed and they perform just as well as any sanded hot-coat only board, so I believe it’s all in the head. Anyhoo, I believe all longboards should be polished, especially if they have color work. A brand new tinted longboard all buffed out looks so bitchin’. As for shortboards, I occasionally polish my shortboards and do wacky things like only polish the rails and wetsand the deck and bottom. I think polished rails look really cool. Polishing the deck of a surfboard is like building a sandcastle because it’s gonna get waxed. If you do a nice clean hot-coat you can give a sanded only board a really good finish. Sometimes the customer can’t tell the difference if you do a nice job. Perfromance wise, I once wetsanded the bottom of a board that was originally polished and it seemed to ride better. I thought it scooted along a little faster. But, like Jim Phillips said, who can really tell? remeber, polishing is waay more labor. Plus, I think you can really tune in the edges better when wetsanding. Sometimes the buffer will knock the edge down a bit(this starts the debate wether any surfer can tell the difference-but oh well).
Yes – but remember in all this that at somepoint increasing the texture > on a surface will produce drag and turbulance. A boat with barnicals on > the hull will not go fast. A plane with frost on the wings will crash. But > a shark with a skin textured to about 100 grit will cut through the water > like a knife.>>> As for a fin, yes it will be faster. But is that a good thing? May make it > more likly to cavitate.>>> Shine All of my fins are made from volan and are sanded finish only.The cavitation problem comes from the foil of the fin.ie,a shrp leading edge vs a fuller rounded leading edge.I have two fins of the same template but one has a thin, sharp leading edge, the other a full, rounde leading edge.There are definite differences,one of which is the sharp edged one will be the one to cavitate.