We live in an area with lots of tanic acid in the water from eel grass. How much does waxing a boat really hurt performance??? I know that it messes up the laminar flow a bit, due to water beading rather than staying attached, but is it really significant?

LOL, you don't realize it but you've brought up a subject that has been debated with religous ferver lots of times. The end result being no decernable difference between waxed/unwaxed for cats.

The only subject I've seen stir up more contention than that one is the question of whether you should trailer with the rudders on/off. The correct answer to that one is "on".

There may be no noticeable difference between the two but I'm fairly sure you won't find many "RACERS" who wax. Using snobol once a month is easier than waxing anyway.

Have Fun
Mike

Rainex.
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Ok, I don't do it, but apparently, some lightning sailors around here do.

Waxing has no impact. The flow on cat hulls and foils is laminar. That means the water that actually touches the hulls does not move.

For years, there have been a lot of people who understand this, have waxed their hulls and stood around watching people do silly things because:

1) They were tired of arguing with idiots applying static behavior to a dynamic situation i.e. "if you look at the way water beads on a waxed hull, you are going to cause bubbles and .... "

2) They were amused by people who didn't know what they were doing wet sanding their hulls to 1200 grit, with the scratches all going in the same direction.

3) Liked to watch the people who had just wet sanded their hulls go into a panic when you told your hull were 3200 grit ( typical grit of a wax/polish)


If you want to really want to go fast, touch up the dings in your hulls and keep the crud washed off.

Carl Bohannon

But does Rainex keep his hulls from being discolored by the tannic acid in the water?

(I'm just posting this to test how the "quote" feature works.)

Wax on, wax off, young son.

Seriously, I wax my H20 a couple of time a year. It keeps the stain off the boat. I've never noticed a performance difference. If anything I think wax is faster because it helps keep the road grime off the hulls. A good looking hull is a fast hull.

Keep One Hull Flying,
Mike Hill
H20 #791

If anything else, waxing makes the hulls look nicer... and if you're gonna suck on the race course, you might as well look sharp doing it!

Well your right the flow is laminar. But to have a good flow besides the abstence of scratchs and dings you need the proper boundry layer. Correct me if I'm wrong,that is the layer that holds the unmoving water. Remember the hull does not sit at a static attitude. It is constantly moving up and down. Wax repels water. That tends to introduce air in the area of the hull that is moving in and out of the water and disturb the laminar. Now that might seem like a small thing to worry about to some but when I spend the time on everything else to make sure it's in top shape I'm not going to smear wax all over my hulls.

Just point out the importance of the boundry layer, you might remember the 3M material called riblets that was applied to the bottom of Stars and Stripes. It was a textured material that held water,thus improving the boundry layer. I built custom sailboats and they are painted with Imron or awlgrip. Finishes which don't require wax. For a while I had a 100 grit finish on my boat and I swear it was the fastest.

If your coming by the causeway to race I encourage you to wax up real good.

Have fun
Mike

According to Frank Bethwaite (author of 'High Performance Sailing',18'skiff, tasar, 59er designer, father of Julian Bethwaite, 49er designer), who has done extensive testing of his claims, the more highly polished a surface is the less drag it has. Laminar flow has significantly lower co-efficients of drag that turburlent flow - this is why modern airliners can fly as fast and efficiently as they do, they use laminar flow foils.

Any imperfections cause the flow to become turbulent thus increasing drag. In tests comparing highly polished centreboards with those sanded slightly to remove the shine, the highly polished boards came out in front every time.

To read an article on this very subject by Frank see:
http://www.bethwaite.com/bethwaite/publications/fastestfoils/fastestfoils_0987.htm

Can waxing give a highly polished surface? If so then waxing would give a low drag surface, better than one that had been sanded. Frank found stainless steel polished to a mirror finish to be very low drag.

Rob.

Ok, I agree about a very smooth surface. Its easy to acomplish. A high speed buffer and a polishing compound that contains no silicone.

the last time Bethwaite was mentioned, it ellicited a bitter response :P

Instead of rainx....try using Mclube....

I wax mine about once a year....

To Wax, or Not to Wax
An Engineering Perspective
http://www.thebeachcats.com/OnTheWire/www.catsail.com/archives/v3-i2/feature4.htm

Here is an article from On The Wire that I came across while browsing.

Malc

Here's my $.02 worth....

I bet the Kiwi's had someone committed to hull preparation, didn't much matter since their boat fell apart!

I sail a 1984 boat, I win some, I lose some.....and I'll bet you everyone who has responded not to wax loses races too. While I'm sure there is a definitive answer on the subject, waxing protects your boats finish and increases the longevity and value of the boat. Think about the REAL speed difference in waxing and not waxing. On a typical triangle (or even a distance course) I seriously doubt it would add up to the time lost by one blown tack or a misjudgment on downhaul/sheet tension, weight distribution, etc. Sail fast and sail smart....wax your boat and be proud of the way it looks, if you lose you can blame it on the shine even though you know it was really your blown tack or the fact that you went high on the course when the leaders went low, etc., etc. etc.

Jeff Worman
SC17 Smokin'

Ok, I see where the problem lies. Some of you think wax and polish are the same thing. One is a protective coating, the other smoothes the surface. Polishing compounds can and are added to wax. I never said sand your hulls,I said don't put wax on them if your racing. I assume that your hulls are polished and smooth.

Malc,I would say forget about the performance question for now. I would suggest you wax your hulls and see how long it takes before the hulls discolor. Now remember how much work you put in to waxing the hulls. Also wax does not nessesarly clean the discoloration on the hulls. This means you will have to use something like snobol first to clean them. Then once they discolor take the snobol wipe them down and see how long it takes for them to discolor again. Decide for yourself which type of maintenance leaves you more time to sail and is simplest and cheaper and....Oh yea, silly. I don't know how much you sail but my boat goes in on friday and stays in until late sunday and it takes about a month and a half before the discoloration gets to the point that I want to clean them. 10 minutes with snobol and they look like new.

The link offered has some incorrect info. Stars and Stripes, the 12 meter had a material that was applied in sheets that had a adheisive backing. Not a polish. Also any gain no matter how small can be important. I'll take 1 foot ahead over one foot behind at the finish line anyday. One of the Tornado sailers was helping another couple with the rigging on their boat in a effort to remove weight. He said they would work on the ounces and that would soon become pounds.

One more thing,orbital buffers that are used for waxing. Some quality orbitals have a very smooth action. Others are brutal. I would use caution vibrating the hull. It could cause a separation of the foam from the outer laminate.

Have Fun
Mike

I stare at how beautiful those shiny white hulls glide through water........and forget about trimming the sails!If Gelcoat is absorbent then water does permeate through it,waxing must in someway reduce water tension so that its not absorbed and it also must deter any foreign matter found in the water to stain the hulls. On our beach a hobie 17 circa 1996 has sat and for the three years I've known it the cat has never been in the water now there are glycol blisters all over whatever touches the sand. Another reason to use or move your boat once in a while or at least wax it.Is a painted hull another story? DSYC

Due to the repulsion of water and wax, I wax my hulls only underneath (to reduce displacement)and aft of the crossbar on the sides. This makes me move like a squeezed watermelon seed on a hot day. Similarly I wax the last two thirds of my rudders to stop them popping up. Rainex is technically illegal, and some clown is bound to protest.

There has been some testing done over the years on wax.

Chemical and piping firms looked at coating the inside of pipes with wax, because it pays off if it reduces the power needed to pump liquid. The result was a waxed surface at a given surface roughness was the same as a unwaxed surface.

There have been a couple of student studies on the effect of wax or polish on boats. One was a link from Mad For Sailing, one I saw at a conference and I know I have read at least one other. The result the better the finish, the lower the drag and the better the flow stays attached (very important for rudders). There was a big improvement between 400 grit and 1000 grit. The difference between highly polished wax and unwaxed surfaces was minimal with a slight edge toward waxed surfaces.

If any of you are students, in need of a project for a lab, especially if you have access to a flow tank, this would be a pretty good research project. You could probably publish in at least one of the major sail magazines.

From an engineering standpoint, I can see pros and cons both ways. I actually pulled out a couple of my Chem E books and did a little research, but....

I figure it helps keep the grime off the hulls, so a smooth clean hull is faster than a dirty one.

But the real difference that I see depends on what part of the boat I put the wax on. If I wax the area around my or my crews feet, I tend to not do as well...I think it stems from my crew taking the stick out of my hands and beating me with it to show me his appreciation for the nice new wax job.

Will