Hull Oxidation

Greg- did you do the whole kit or just the vertglass part? I just got the whole kit in the mail today and will probably start the process today.

I did the Oxidation Removal with the scrubby pad they provided. I went around twice washing the boat off periodically. Then I waited a day and washed the boat using Step 2 boat wash. Let that dry completely..
Finally I painted on Step 3 and I just continuously painted till I had 6 or 7 (I lost track, quite frankly, cause I was listening to the Red Sox game at the time)coats on. My hands were sick of painting and it was getting dark so that is all I've done and I still have enough stuff to put more coats on at the beginning of next season if I want.
Good Luck. Hope you get the same results I did.
Greg

Yes - but the affect would be ever so slight and tiny that it wouldn't be measureable. If you were trying to move the hull through air closer to the speed of sound - yes, it might make a measureable difference. However, at highway speed, the resistance due to airflow is more about profile drag than skin drag...and when changing the finish of a suface on the magnitude of these coatings, you would be affecting skin drag.

Skin drag is largely affected by how thin/thick the boundary layer of turbulent airflow is between the skin of the object and the smooth laminar air flow around the object. There is so much outside turbulance coming from other cars, the tow vehicle, and cross breezes that your not going to get a steady boundary layer no matter what you do. Hence the skin drag (through air) can't be significantly impacted by a coating on this level and at these speeds.

Disrespecting laminar flow?!? BLASPHEMY!!

I'll Paypal money for a six of Newcastle Brown Ale to anyone that can post a reference to a credible, objectively executed drag test that puts to rest the hydrophobic/hydrophilic debate. Preferably with a .edu, .nasa.gov or .navy.mil URL. I have yet to find one.

Just finished with the oxidation removal (FLIPPIN WATER STAINS!) and wash... looks better already... but as with washing anything- the flaws really stand out when you look at it THAT closely.

Did you take "before" pictures???? Hope so. Love to see them.

Greg

More after photos......

Last one....

I'll double that ante!

Jake,

Check out Bethwaite's book. I believe he mentioned something about waxing vs. not waxing his "GREAT ALMIGHTY AUSSIE SKIFF".

It's not documentable enough to win the brew, but it's a start.

I agree with the comments that polishing hulls does accomplish two things:
(1) it puts you in a racing mindset by focusing your brain on going fast
(2) it offers you the opportunity for CLOSE inspection of the hull, and you can spot and repair scratches, road grime, crud, etc. that could slow you down.

Last time I polished the hulls (about every 6 months), I noticed some scratches that I repaired. I wash the hulls before every race, and I once found that my daggarboard tape was sticking down (which has GOT to be slow), and fixed it.

This probably is only something the top sailors need worry about, since more of us blow races from bad tactics, bad technique, or just bad manners....

Either that or someone can Paypal me $100k and I could get some time in the Navy's tow tank at Carderock.

\
OK, but you owe me big time.
I was RC at the Savannah Olympics and we had a couple of lay days. I was staying in my RV behind a warehouse that had a couple of old wrecked cars.
So, I decided to do a speed test on surfaces.
The hood of this car was slightly downhill.
I set up several race tracks for drops of water to compare the time it took for each drop of water to move down it's race course.
Here are the race tracks
1)nothing
2)polish and/or wax
3)McLube
4)Rainex
5)McLube and Rainex

Results (as I vaguely remember them):
1)nothing = the drop did not move
2)polish and/or wax = the drop did not move
3)McLube = 9 seconds
4)Rainex = 11 seconds
5)McLube and Rainex = 1 second

Now if we could just keep McLube and Rainex on our hulls all the time, we would really be hot. <img src=

alt=

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When I got my diesel RV Stan Woodruff and I pushed it pretty hard and when we arrive at Sandy Hook for the Wave NAs, the boats were pretty dirty from the diesel soot.
Stanly worked hard for hours cleaning his hulls, but meanwhile I had talked to Mary. She explained that diesel soot is a long chain polymer.
I won the regatta. <img src=

alt=

/>
Rick
)

Greg,
Your original hulls looked pretty good compared to many I've seen. I recall you did a lot of work on them a little while back. Now that you've "Verted" your hulls they look great. Congratulations! If you applied the stuff correctly and continue to re-apply it according to the specs, you'll be a happy guy. By some of your comments, I noticed you misunderstand some of my comments. As do several others. You don't have to appologize to me. Listening to the feedback, I think we're talking past one another. I'm pleased somebody finally did something. Several times now I suggested some advantqages to using UV protectants, irrespective of brand. If it makes anyone feel better to use one instead of the other, by all means do so. Something is usually better than nothing. If you're the kind of person who's curious, or even skeptical, about the kind of marketing claims we are all continually bombarded with in this country, then you'd probably want to ask any number of probing questions to help yourself sort things out to your advantage, not Madison Ave. advantage.

I'm loath to open up Pandora's box (sorry Jake) and start discussing avionics. If I read this thread correctly it seems that it's more important to be right than correct. Jake is incorrect regarding whether these products, when properly applied, decreases drag. I don't think anything I can say will change that. I'm not even sure Rick's experiment will suffice. Jake and SteveH and those who doubt the drag reduction comment, would be better advised to go to a credible Physics Department on their local college campus and see if they can bend the ear of one of the post docs for an explanation.

Mary,
It sounds like you first must determine if this stuff makes things go faster in water, before you can move on and discover whether it does the same for an airfoil. I think you've indicated that your boat already goes fast enough, so I fail to see any advantage in doing a test. And you'd also have to move from the hypothetical to the material. I think the greater advantage for you may be in trailering. You would arrive at your destination with a cleaner pair of hulls or hulls that would wash the road grim off with less effort.

SteveH,
A six pack of beer, especially Newcastle, isn't much of a stimulus. Last time I was there the Britts don't even drink the stuff since they started pasturizing it; it's kinda like Bud for them. However, as I suggested a visit to your local campus may find a more willing taker. There is a caveat though, in addition to maintaining healthy skepticism when you walk through the doors of the physics lab, your required to have an open mind.

PTP,
Whether you need to use the entire kit depends upon the condition of your hulls.

In case any of you are still sailing out there, today was nasty. Steady between 20 and 25 and frequent gusts of 30 and better. As a newcomer I reserve the right of silence regarding whether we went over or not. Unfortunately no other cats were on the lake. There was a group of diehard boarders and some fall kite sailors out. Sailed an F18 all morning and a 6.0 this afternoon. We could take all but a couple of the boarders, I suppose because of the heavy waves. I'm sworn to secrecy so I can't disclose whether the hulls were coated and if so, what with. You know how it goes, ...orders from headquarters.

Daniel

OBJECTIVE DATA!!! Rick, you've at least earned a couple of bottles of substandard beer. However, not sure that it's 100% applicable. The surface tension of the droplet would play a part in the race and wouldn't on a hull. Also, in my googling of 'hydrophobic hydrophilic drag test,' I came across a reference stating that some coatings can be hydrophobic in air and hydrophilic in water. So if the RainX/McLube coating is hydrophobic/hydrophilic, which side wins? Yeah, I know, doesn't make sense to me, either.

Daniel, thanks for the suggestion, but almost half the people in my hallway at work are physics Ph.D's and I wouldn't trust them on SWAGging this nor on running the test. All I've seen for both sides until Rick's results is ad claims and intuitively obvious anecdotal evidence put forth by messageboard experts based on some other messageboard expert's intuitively obvious anecdotal evidence. I'm not claiming to be either right or correct, but if you can't bring anything objective to the table, then no beer for you. BTW, I'm fine with Pandora's boxes.

How about the one where Hydrophobic wax (regular 'ol wax) would make your boat float higher because it pushes water away?

I'm an enginerd and have never heard any testing that anyone performed that was objective and thorough in relation to waxy, oily, or wetsanded hull bottoms flowing through water. You can tell me until you are blue in the face that you think your boat is faster with this coating or that or that you were faster than sombody else without but it's not objective. As an example, it always seems like my truck runs better after a washing although I know it's physically impossible. Point is, personal opinion and "feel" are not adequate enough to stake a claim on some scientific result. Show me the money! Until then, I'll focus on keeping the bottom of my boat clean and fair and trying to avoid mistakes on the course.

Here's the kind of test that doesn't cut it. It's for the hydrophilic coating, Hyspeedkote. The results look interesting. Interesting enough to include in a test, but there are too many uncontrolled unknowns in real-world testing. This is what it takes for a thorough, objective test. A controlled environment, a carriage that can maintain a set speed and electronics to measure small differences in forces.

BTW, that's me on the plank. Seriously, $100k and a week at that tank and the answer is known.

Would a hydrophilic coating make the boat sit lower in the water?

All this stuff is bringing back my ice cream headache. Hydrophobic, Hydrophilic, it's all Hydro-PHALLIC to me....

All I wanted was purty, shiny hulls and I got em.

New question..... Triradial vs. Horizontal-cut dacron sails.
What is the difference? Why do I want one or the other. Why does Triradial cut cost a lot more? $820 vs $ 975 from Calvert for a 5.0 oz Yellow Square-Top Dacron Main.
Thanks
Greg

Wouldn't a thicker boundary layer produce less drag? Wouldn't a surface that is not as slippery to water produce that thicker boundary layer? Wouldn't this lead us to the non waxed/coated/slippery hulls being faster?

The box has been opened further.

Triradial is better because it aligns the fibers in the direction of stress on the sail. Thus the sail is consistently stretched throughout.

Triradial costs more because you waste more material when building the sail because of the many cuts.

Mike Hill
www.stlouiscats.com

The pre pictures are further back in this forum. I am not sure the pictures do it justice, but the system is pretty amazing with vertglass... it was amazing to see all the oxidation washed off the boat with the first step.. I have no idea how many coats I did with the vertglas- maybe 6 or so- some parts more than others. It DOES look like a new boat... now I guess I have to do the centerboards.. ugh

and another

last one... then maybe this thread should go bye bye.

Looks good. Glad you like it. It's really hard to take pictures that do it justice. In person it's much more impressive.

Have a great weekend.
Greg

Busy week,
But I do have some comments.
Greg your boat looks good. I have a friend that purchased a older faded yellow H14 and I plan on getting him to try it. Good tip Jake. I have seen this stuff at boat shows but I am skeptical of these kind of products and am tired of wasting my money on the latest quick fix that doesn't work. Fact is it's still just a band aid but the best I've seen so far.

I preface my comments with some of my experience just so you know. In the late 70's early 80's I worked for KIWI BOATS. We built custom one-off racing yachts. IMP,LOVE MACHINE, EVERGREEN, KIALOA IV. Just to name a very few. We were on the cutting edge building composite,balsa cored boats. Back then we built them on a male mold. As you might guess the outside of the boat is raw glass and has to be finished by hand. So how do you fair a 81 ft. hull to perfection? Sandpaper, fart rock, putty,epoxy primer, paint and a lot of work day and night. We also built the KIWI 40 and MINI TONNER in female molds. Those had gel coat exteriors. For the last 22 years I've worked in my own business touching up cars. The last 5 for high end dealers only. I have had Cats since 1982.
I don't claim to know everything but I do have a good working knowledge of finishes painted and gel coated.

One other thing Greg, none of us really explained why your hulls look good for a short time after you buffed and waxed and then go bad so fast. Picture a cross section of the surface. A new surface is smooth. A degraded surface looks like a mountian range with peaks, valleys and slopes. When you buff you polish only the peaks. Not the slopes which depending on how bad the surface is has much more surface area than the
peaks. You have done nothing to polish or remove the oxidation from the slopes and valleys. Wax leaves, right back where you started.

If the gel coat is not that badly degraded it can be sanded and polished. We have first hand experience not coming from me but MBOUNDS. He lays out a good schedule of sanding. The only thing I would add is a guide coat so you don't over sand or under sand. A guide coat is simply a can of flat black spray paint. Dust it very lightly on before you start sanding. Sand until the paint is gone. This will also show the highs and lows which may be too much info for some. Sanding should be done by hand with a board file and there is a right way to sand. I could go on and on about this and if anyone wants to know more PM with your PH# and I'll gladly call you and discuss it.

Fact is there is only few ways to fix bad gel coat. Polish,sand and polish,re-gel coat or paint.

Daniel,
This comment,are you speaking of yourself? Let me straighten you out on a some of things. My comment about polishing my painted hulls meant after four years they looked as good as the day they were painted. Like Greg's hulls do now. I don't use wax,I was simply trying show the guy who bought my boat how nice it could look. It's all I had at the time. I have argued against waxing for racing on this forum before. The paint has lasted longer than any gel coated surface I have seen.

You say don't sand and buff, but you say it's ok to use a rag and compound. Talk about paddling upstream. The gel coated surface of a cat is the best surface you could ever get to buff for an amateur. It's not that hard to learn.

I've given you examples of painted boats. No comment?

I did go buy some 303. 16 oz bottle. Now it may help keep a new boat looking new. The bottle says 100% Prevention of UV caused slow-fade with regular use. SPF 40 for your stuff. Like your comment about Vertglas I doubt it. I can tell you that on the places I tried it there was no difference in color or sheen. I used a third of the bottle just on my decks in front of the main beam. It does not make an old boat that needs restoration look better. I have friends whose boats have aluminum strips on the bottom of their boats to help protect the hulls from beaching. Trust me the aluminum wears. This stuff will not prevent any wear from the beach.

Referencing your comment above. A lot of people visit this site to get info. Some are people that have never had a boat before. Make sure you don't cause them to paddle upstream.

As much as I do like the vertglass- I agree.. nothing will protect the boat from being dragged on the sand- in fact.. when I was using the oxidation remover you could tell there was less oxidation under the boat from the "polishing" of draggin it across the sand occassionally (although, admittedly, the bottom of the hulls get less UV rad).

Steveh,
He may not have the credentials your looking for but Jack Sammons wrote on this subject in his book Welcome to A-Fleet. I think he's in the sailing hall of fame on this site. He discusses the various drag layers and does not recommend wax for racing. Though the book is written for the Hobie 16 it has a lot of good info and is well worth reading. It's also fun to read. Problem is I don't know if it's still in print. Someone has to have a copy.

Rick, did you use regular RainX or the concentrate that you add to the water in the washer fluid tank?

Jake, I'm thinking if you push the water away you go deeper.

Assume a glass-smooth finish. The problem as I see it is that, according to boundary layer theory, that very first layer of water next to the hull is going at hull speed no matter what the surface is. So unless that magic coating can allow that first layer of water slip by in violation of the theory, what's to improve on?

Steve,

The navy has been working on this for years. They discovered years ago that dolphins and whales as well as many fish exhibit far less drag than theory says they should given their shapes. They think they have it down to some substance exuded by their skin. Every now and then you hear a little blurb about it but I have not seen anything published recently. Not suprising with the Russians revealing their FULLY OPERATIONAL super-cavitating torpedoes. Can you say ketchup?

Jimbo

Maybe it's not as complicated as we think it is.